recording cvs-1.6 file death

6 files changed, 0 insertions, 13100 deletions

diff --git a/gnu/lib/libg++/include/regex.h b/gnu/lib/libg++/include/regex.h
deleted file mode 100644
index 9e404e8..0000000
--- a/gnu/lib/libg++/include/regex.h
+++ /dev/null
@@ -1,272 +0,0 @@
-/* Definitions for data structures callers pass the regex library.
-
-   Copyright (C) 1985, 1989-92 Free Software Foundation, Inc.
-
-This file is part of the GNU C++ Library.  This library is free
-software; you can redistribute it and/or modify it under the terms of
-the GNU Library General Public License as published by the Free
-Software Foundation; either version 2 of the License, or (at your
-option) any later version.  This library is distributed in the hope
-that it will be useful, but WITHOUT ANY WARRANTY; without even the
-implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
-PURPOSE.  See the GNU Library General Public License for more details.
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the Free Software
-Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-#ifndef __REGEXP_LIBRARY
-#define __REGEXP_LIBRARY
-
-#if defined(SHORT_NAMES) || defined(VMS)
-#define re_compile_pattern	recmppat
-#define re_pattern_buffer	repatbuf
-#define re_registers		reregs
-#endif
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* Define number of parens for which we record the beginnings and ends.
-   This affects how much space the `struct re_registers' type takes up.  */
-#ifndef RE_NREGS
-#define RE_NREGS 10
-#endif
-
-#define BYTEWIDTH 8
-
-
-/* Maximum number of duplicates an interval can allow.  */
-#ifndef RE_DUP_MAX /* kludge for AIX, which defines it */
-#define RE_DUP_MAX  ((1 << 15) - 1) 
-#endif
-
-/* This defines the various regexp syntaxes.  */
-extern int obscure_syntax;
-
-
-/* The following bits are used in the obscure_syntax variable to choose among
-   alternative regexp syntaxes.  */
-
-/* If this bit is set, plain parentheses serve as grouping, and backslash
-     parentheses are needed for literal searching.
-   If not set, backslash-parentheses are grouping, and plain parentheses
-     are for literal searching.  */
-#define RE_NO_BK_PARENS	1
-
-/* If this bit is set, plain | serves as the `or'-operator, and \| is a 
-     literal.
-   If not set, \| serves as the `or'-operator, and | is a literal.  */
-#define RE_NO_BK_VBAR (1 << 1)
-
-/* If this bit is not set, plain + or ? serves as an operator, and \+, \? are 
-     literals.
-   If set, \+, \? are operators and plain +, ? are literals.  */
-#define RE_BK_PLUS_QM (1 << 2)
-
-/* If this bit is set, | binds tighter than ^ or $.
-   If not set, the contrary.  */
-#define RE_TIGHT_VBAR (1 << 3)
-
-/* If this bit is set, then treat newline as an OR operator.
-   If not set, treat it as a normal character.  */
-#define RE_NEWLINE_OR (1 << 4)
-
-/* If this bit is set, then special characters may act as normal
-   characters in some contexts. Specifically, this applies to:
-	^ -- only special at the beginning, or after ( or |;
-	$ -- only special at the end, or before ) or |;
-	*, +, ? -- only special when not after the beginning, (, or |.
-   If this bit is not set, special characters (such as *, ^, and $)
-   always have their special meaning regardless of the surrounding
-   context.  */
-#define RE_CONTEXT_INDEP_OPS (1 << 5)
-
-/* If this bit is not set, then \ before anything inside [ and ] is taken as 
-     a real \.
-   If set, then such a \ escapes the following character.  This is a
-     special case for awk.  */
-#define RE_AWK_CLASS_HACK (1 << 6)
-
-/* If this bit is set, then \{ and \} or { and } serve as interval operators.
-   If not set, then \{ and \} and { and } are treated as literals.  */
-#define RE_INTERVALS (1 << 7)
-
-/* If this bit is not set, then \{ and \} serve as interval operators and 
-     { and } are literals.
-   If set, then { and } serve as interval operators and \{ and \} are 
-     literals.  */
-#define RE_NO_BK_CURLY_BRACES (1 << 8)
-
-/* If this bit is set, then character classes are supported; they are:
-     [:alpha:],	[:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
-     [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
-   If not set, then character classes are not supported.  */
-#define RE_CHAR_CLASSES (1 << 9)
-
-/* If this bit is set, then the dot re doesn't match a null byte.
-   If not set, it does.  */
-#define RE_DOT_NOT_NULL (1 << 10)
-
-/* If this bit is set, then [^...] doesn't match a newline.
-   If not set, it does.  */
-#define RE_HAT_NOT_NEWLINE (1 << 11)
-
-/* If this bit is set, back references are recognized.
-   If not set, they aren't.  */
-#define RE_NO_BK_REFS (1 << 12)
-
-/* If this bit is set, back references must refer to a preceding
-   subexpression.  If not set, a back reference to a nonexistent
-   subexpression is treated as literal characters.  */
-#define RE_NO_EMPTY_BK_REF (1 << 13)
-
-/* If this bit is set, bracket expressions can't be empty.  
-   If it is set, they can be empty.  */
-#define RE_NO_EMPTY_BRACKETS (1 << 14)
-
-/* If this bit is set, then *, +, ? and { cannot be first in an re or
-   immediately after a |, or a (.  Furthermore, a | cannot be first or
-   last in an re, or immediately follow another | or a (.  Also, a ^
-   cannot appear in a nonleading position and a $ cannot appear in a
-   nontrailing position (outside of bracket expressions, that is).  */
-#define RE_CONTEXTUAL_INVALID_OPS (1 << 15)
-
-/* If this bit is set, then +, ? and | aren't recognized as operators.
-   If it's not, they are.  */
-#define RE_LIMITED_OPS (1 << 16)
-
-/* If this bit is set, then an ending range point has to collate higher
-     or equal to the starting range point.
-   If it's not set, then when the ending range point collates higher
-     than the starting range point, the range is just considered empty.  */
-#define RE_NO_EMPTY_RANGES (1 << 17)
-
-/* If this bit is set, then a hyphen (-) can't be an ending range point.
-   If it isn't, then it can.  */
-#define RE_NO_HYPHEN_RANGE_END (1 << 18)
-
-
-/* Define combinations of bits for the standard possibilities.  */
-#define RE_SYNTAX_POSIX_AWK (RE_NO_BK_PARENS | RE_NO_BK_VBAR \
-			| RE_CONTEXT_INDEP_OPS)
-#define RE_SYNTAX_AWK (RE_NO_BK_PARENS | RE_NO_BK_VBAR \
-			| RE_CONTEXT_INDEP_OPS | RE_AWK_CLASS_HACK)
-#define RE_SYNTAX_EGREP (RE_NO_BK_PARENS | RE_NO_BK_VBAR \
-			| RE_CONTEXT_INDEP_OPS | RE_NEWLINE_OR)
-#define RE_SYNTAX_GREP (RE_BK_PLUS_QM | RE_NEWLINE_OR)
-#define RE_SYNTAX_EMACS 0
-#define RE_SYNTAX_POSIX_BASIC (RE_INTERVALS | RE_BK_PLUS_QM 		\
-			| RE_CHAR_CLASSES | RE_DOT_NOT_NULL 		\
-                        | RE_HAT_NOT_NEWLINE | RE_NO_EMPTY_BK_REF 	\
-                        | RE_NO_EMPTY_BRACKETS | RE_LIMITED_OPS		\
-                        | RE_NO_EMPTY_RANGES | RE_NO_HYPHEN_RANGE_END)	
-                        
-#define RE_SYNTAX_POSIX_EXTENDED (RE_INTERVALS | RE_NO_BK_CURLY_BRACES	   \
-			| RE_NO_BK_VBAR | RE_NO_BK_PARENS 		   \
-                        | RE_HAT_NOT_NEWLINE | RE_CHAR_CLASSES 		   \
-                        | RE_NO_EMPTY_BRACKETS | RE_CONTEXTUAL_INVALID_OPS \
-                        | RE_NO_BK_REFS | RE_NO_EMPTY_RANGES 		   \
-                        | RE_NO_HYPHEN_RANGE_END)
-
-
-/* This data structure is used to represent a compiled pattern.  */
-
-struct re_pattern_buffer
-  {
-    char *buffer;	/* Space holding the compiled pattern commands.  */
-    long allocated;	/* Size of space that `buffer' points to. */
-    long used;		/* Length of portion of buffer actually occupied  */
-    char *fastmap;	/* Pointer to fastmap, if any, or zero if none.  */
-			/* re_search uses the fastmap, if there is one,
-			   to skip over totally implausible characters.  */
-    char *translate;	/* Translate table to apply to all characters before 
-		           comparing, or zero for no translation.
-			   The translation is applied to a pattern when it is 
-                           compiled and to data when it is matched.  */
-    char fastmap_accurate;
-			/* Set to zero when a new pattern is stored,
-			   set to one when the fastmap is updated from it.  */
-    char can_be_null;   /* Set to one by compiling fastmap
-			   if this pattern might match the null string.
-			   It does not necessarily match the null string
-			   in that case, but if this is zero, it cannot.
-			   2 as value means can match null string
-			   but at end of range or before a character
-			   listed in the fastmap.  */
-  };
-
-
-/* search.c (search_buffer) needs this one value.  It is defined both in
-   regex.c and here.  */
-#define RE_EXACTN_VALUE 1
-
-
-/* Structure to store register contents data in.
-
-   Pass the address of such a structure as an argument to re_match, etc.,
-   if you want this information back.
-
-   For i from 1 to RE_NREGS - 1, start[i] records the starting index in
-   the string of where the ith subexpression matched, and end[i] records
-   one after the ending index.  start[0] and end[0] are analogous, for
-   the entire pattern.  */
-
-struct re_registers
-  {
-    int start[RE_NREGS];
-    int end[RE_NREGS];
-  };
-
-
-
-#if defined(__STDC__) || defined(__cplusplus)
-
-extern char *re_compile_pattern (const char *, int, struct re_pattern_buffer *);
-/* Is this really advertised?  */
-extern void re_compile_fastmap (struct re_pattern_buffer *);
-extern int re_search (struct re_pattern_buffer *, char*, int, int, int,
-		      struct re_registers *);
-extern int re_search_2 (struct re_pattern_buffer *, char *, int,
-			char *, int, int, int,
-			struct re_registers *, int);
-extern int re_match (struct re_pattern_buffer *, char *, int, int,
-		     struct re_registers *);
-extern int re_match_2 (struct re_pattern_buffer *, char *, int,
-		       char *, int, int, struct re_registers *, int);
-
-#if 0
-/* 4.2 bsd compatibility.  */
-extern char *re_comp (char *);
-extern int re_exec (char *);
-#endif
-
-#else /* !__STDC__ */
-
-#define const /* nothing */
-extern char *re_compile_pattern ();
-/* Is this really advertised? */
-extern void re_compile_fastmap ();
-extern int re_search (), re_search_2 ();
-extern int re_match (), re_match_2 ();
-
-#if 0
-/* 4.2 bsd compatibility.  */
-extern char *re_comp ();
-extern int re_exec ();
-#endif
-
-#endif /* __STDC__ */
-
-
-#ifdef SYNTAX_TABLE
-extern char *re_syntax_table;
-#endif
-
-#ifdef __cplusplus
-extern int re_max_failures;
-}
-#endif
-
-#endif /* !__REGEXP_LIBRARY */
diff --git a/gnu/usr.bin/awk/gawk.texi b/gnu/usr.bin/awk/gawk.texi
deleted file mode 100644
index b280262..0000000
--- a/gnu/usr.bin/awk/gawk.texi
+++ /dev/null
@@ -1,11270 +0,0 @@
-\input texinfo   @c -*-texinfo-*-
-@c %**start of header (This is for running Texinfo on a region.)
-@setfilename gawk.info
-@settitle The GAWK Manual
-@c @smallbook
-@c %**end of header (This is for running Texinfo on a region.)
-
-@ifinfo
-@synindex fn cp
-@synindex vr cp
-@end ifinfo
-@iftex
-@syncodeindex fn cp
-@syncodeindex vr cp
-@end iftex
-
-@c If "finalout" is commented out, the printed output will show
-@c black boxes that mark lines that are too long.  Thus, it is
-@c unwise to comment it out when running a master in case there are
-@c overfulls which are deemed okay.
-
-@iftex
-@finalout
-@end iftex
-
-@c ===> NOTE! <==
-@c Determine the edition number in *four* places by hand:
-@c   1. First ifinfo section  2. title page  3. copyright page 4. top node
-@c To find the locations, search for !!set
-
-@ifinfo
-This file documents @code{awk}, a program that you can use to select
-particular records in a file and perform operations upon them.
-
-This is Edition 0.15 of @cite{The GAWK Manual}, @*
-for the 2.15 version of the GNU implementation @*
-of AWK.
-
-Copyright (C) 1989, 1991, 1992, 1993 Free Software Foundation, Inc.
-
-Permission is granted to make and distribute verbatim copies of
-this manual provided the copyright notice and this permission notice
-are preserved on all copies.
-
-@ignore
-Permission is granted to process this file through TeX and print the
-results, provided the printed document carries copying permission
-notice identical to this one except for the removal of this paragraph
-(this paragraph not being relevant to the printed manual).
-
-@end ignore
-Permission is granted to copy and distribute modified versions of this
-manual under the conditions for verbatim copying, provided that the entire
-resulting derived work is distributed under the terms of a permission
-notice identical to this one.
-
-Permission is granted to copy and distribute translations of this manual
-into another language, under the above conditions for modified versions,
-except that this permission notice may be stated in a translation approved
-by the Foundation.
-@end ifinfo
-
-@setchapternewpage odd
-
-@c !!set edition, date, version
-@titlepage
-@title The GAWK Manual
-@subtitle Edition 0.15
-@subtitle April 1993
-@author Diane Barlow Close
-@author Arnold D. Robbins
-@author Paul H. Rubin
-@author Richard Stallman
-
-@c Include the Distribution inside the titlepage environment so
-@c that headings are turned off.  Headings on and off do not work.
-
-@page
-@vskip 0pt plus 1filll
-Copyright @copyright{} 1989, 1991, 1992, 1993 Free Software Foundation, Inc.
-@sp 2
-        
-@c !!set edition, date, version
-This is Edition 0.15 of @cite{The GAWK Manual}, @*
-for the 2.15 version of the GNU implementation @*
-of AWK.
-
-@sp 2
-Published by the Free Software Foundation @*
-675 Massachusetts Avenue @*
-Cambridge, MA 02139 USA @*
-Printed copies are available for $20 each.
-
-Permission is granted to make and distribute verbatim copies of
-this manual provided the copyright notice and this permission notice
-are preserved on all copies.
-
-Permission is granted to copy and distribute modified versions of this
-manual under the conditions for verbatim copying, provided that the entire
-resulting derived work is distributed under the terms of a permission
-notice identical to this one.
-
-Permission is granted to copy and distribute translations of this manual
-into another language, under the above conditions for modified versions,
-except that this permission notice may be stated in a translation approved
-by the Foundation.
-@end titlepage
-
-@ifinfo
-@node Top, Preface, (dir), (dir)
-@comment  node-name,  next,  previous,  up
-@top General Introduction
-@c Preface or Licensing nodes should come right after the Top
-@c node, in `unnumbered' sections, then the chapter, `What is gawk'.
-
-This file documents @code{awk}, a program that you can use to select
-particular records in a file and perform operations upon them.
-
-@c !!set edition, date, version
-This is Edition 0.15 of @cite{The GAWK Manual}, @*
-for the 2.15 version of the GNU implementation @*
-of AWK.
-
-@end ifinfo
-
-@menu
-* Preface::                     What you can do with @code{awk}; brief history
-                                and acknowledgements.
-* Copying::                     Your right to copy and distribute @code{gawk}.
-* This Manual::                 Using this manual. 
-                                Includes sample input files that you can use.
-* Getting Started::             A basic introduction to using @code{awk}.
-                                How to run an @code{awk} program.  
-                                Command line syntax.
-* Reading Files::               How to read files and manipulate fields.
-* Printing::                    How to print using @code{awk}.  Describes the
-                                @code{print} and @code{printf} statements.  
-                                Also describes redirection of output.
-* One-liners::                  Short, sample @code{awk} programs.
-* Patterns::                    The various types of patterns 
-                                explained in detail.
-* Actions::                     The various types of actions are
-                                introduced here.  Describes
-                                expressions and the various operators in
-                                detail.  Also describes comparison expressions.
-* Expressions::                 Expressions are the basic building
-                                blocks of statements.
-* Statements::                  The various control statements are 
-                                described in detail.
-* Arrays::                      The description and use of arrays.  
-                                Also includes array-oriented control 
-                                statements.
-* Built-in::                    The built-in functions are summarized here.
-* User-defined::                User-defined functions are described in detail.
-* Built-in Variables::          Built-in Variables
-* Command Line::                How to run @code{gawk}.
-* Language History::            The evolution of the @code{awk} language.
-* Installation::                Installing @code{gawk} under 
-                                various operating systems.
-* Gawk Summary::                @code{gawk} Options and Language Summary.
-* Sample Program::              A sample @code{awk} program with a 
-                                complete explanation.
-* Bugs::                        Reporting Problems and Bugs.
-* Notes::                       Something about the 
-                                implementation of @code{gawk}.
-* Glossary::                    An explanation of some unfamiliar terms.
-* Index::                       
-@end menu
-
-@node Preface, Copying, Top, Top
-@comment  node-name,  next,  previous,  up
-@unnumbered Preface
-
-@iftex
-@cindex what is @code{awk}
-@end iftex
-If you are like many computer users, you would frequently like to make
-changes in various text files wherever certain patterns appear, or
-extract data from parts of certain lines while discarding the rest.  To
-write a program to do this in a language such as C or Pascal is a
-time-consuming inconvenience that may take many lines of code.  The job
-may be easier with @code{awk}.
-
-The @code{awk} utility interprets a special-purpose programming language
-that makes it possible to handle simple data-reformatting jobs easily
-with just a few lines of code.
-
-The GNU implementation of @code{awk} is called @code{gawk}; it is fully
-upward compatible with the System V Release 4 version of
-@code{awk}.  @code{gawk} is also upward compatible with the @sc{posix}
-(draft) specification of the @code{awk} language.  This means that all
-properly written @code{awk} programs should work with @code{gawk}.
-Thus, we usually don't distinguish between @code{gawk} and other @code{awk}
-implementations in this manual.@refill
-
-@cindex uses of @code{awk}
-This manual teaches you what @code{awk} does and how you can use
-@code{awk} effectively.  You should already be familiar with basic
-system commands such as @code{ls}.  Using @code{awk} you can: @refill
-
-@itemize @bullet
-@item
-manage small, personal databases
-
-@item
-generate reports
-
-@item
-validate data
-@item
-produce indexes, and perform other document preparation tasks
-
-@item
-even experiment with algorithms that can be adapted later to other computer
-languages
-@end itemize
-
-@iftex
-This manual has the difficult task of being both tutorial and reference.
-If you are a novice, feel free to skip over details that seem too complex.
-You should also ignore the many cross references; they are for the
-expert user, and for the on-line Info version of the manual.
-@end iftex
-
-@menu
-* History::                     The history of @code{gawk} and
-                                @code{awk}.  Acknowledgements.
-@end menu
-
-@node History,  , Preface, Preface
-@comment  node-name,  next,  previous,  up
-@unnumberedsec History of @code{awk} and @code{gawk}
-
-@cindex acronym
-@cindex history of @code{awk}
-The name @code{awk} comes from the initials of its designers: Alfred V.
-Aho, Peter J. Weinberger, and Brian W. Kernighan.  The original version of
-@code{awk} was written in 1977.  In 1985 a new version made the programming
-language more powerful, introducing user-defined functions, multiple input
-streams, and computed regular expressions.
-This new version became generally available with System V Release 3.1.
-The version in System V Release 4 added some new features and also cleaned
-up the behavior in some of the ``dark corners'' of the language.
-The specification for @code{awk} in the @sc{posix} Command Language
-and Utilities standard further clarified the language based on feedback
-from both the @code{gawk} designers, and the original @code{awk}
-designers.@refill
-
-The GNU implementation, @code{gawk}, was written in 1986 by Paul Rubin
-and Jay Fenlason, with advice from Richard Stallman.  John Woods
-contributed parts of the code as well.  In 1988 and 1989, David Trueman, with
-help from Arnold Robbins, thoroughly reworked @code{gawk} for compatibility
-with the newer @code{awk}.  Current development (1992) focuses on bug fixes,
-performance improvements, and standards compliance.
-
-We need to thank many people for their assistance in producing this
-manual.  Jay Fenlason contributed many ideas and sample programs.  Richard
-Mlynarik and Robert J. Chassell gave helpful comments on early drafts of this
-manual.  The paper @cite{A Supplemental Document for @code{awk}} by John W.
-Pierce of the Chemistry Department at UC San Diego, pinpointed several
-issues relevant both to @code{awk} implementation and to this manual, that
-would otherwise have escaped us.  David Trueman, Pat Rankin, and Michal
-Jaegermann also contributed sections of the manual.@refill
-
-The following people provided many helpful comments on this edition of
-the manual: Rick Adams, Michael Brennan, Rich Burridge, Diane Close,
-Christopher (``Topher'') Eliot, Michael Lijewski, Pat Rankin, Miriam Robbins,
-and Michal Jaegermann.  Robert J. Chassell provided much valuable advice on
-the use of Texinfo.
-
-Finally, we would like to thank Brian Kernighan of Bell Labs for invaluable
-assistance during the testing and debugging of @code{gawk}, and for
-help in clarifying numerous points about the language.@refill
-
-@node Copying, This Manual, Preface, Top
-@unnumbered GNU GENERAL PUBLIC LICENSE
-@center Version 2, June 1991
-
-@display
-Copyright @copyright{} 1989, 1991 Free Software Foundation, Inc.
-675 Mass Ave, Cambridge, MA 02139, USA
-
-Everyone is permitted to copy and distribute verbatim copies
-of this license document, but changing it is not allowed.
-@end display
-
-@c fakenode --- for prepinfo
-@unnumberedsec Preamble
-
-  The licenses for most software are designed to take away your
-freedom to share and change it.  By contrast, the GNU General Public
-License is intended to guarantee your freedom to share and change free
-software---to make sure the software is free for all its users.  This
-General Public License applies to most of the Free Software
-Foundation's software and to any other program whose authors commit to
-using it.  (Some other Free Software Foundation software is covered by
-the GNU Library General Public License instead.)  You can apply it to
-your programs, too.
-
-  When we speak of free software, we are referring to freedom, not
-price.  Our General Public Licenses are designed to make sure that you
-have the freedom to distribute copies of free software (and charge for
-this service if you wish), that you receive source code or can get it
-if you want it, that you can change the software or use pieces of it
-in new free programs; and that you know you can do these things.
-
-  To protect your rights, we need to make restrictions that forbid
-anyone to deny you these rights or to ask you to surrender the rights.
-These restrictions translate to certain responsibilities for you if you
-distribute copies of the software, or if you modify it.
-
-  For example, if you distribute copies of such a program, whether
-gratis or for a fee, you must give the recipients all the rights that
-you have.  You must make sure that they, too, receive or can get the
-source code.  And you must show them these terms so they know their
-rights.
-
-  We protect your rights with two steps: (1) copyright the software, and
-(2) offer you this license which gives you legal permission to copy,
-distribute and/or modify the software.
-
-  Also, for each author's protection and ours, we want to make certain
-that everyone understands that there is no warranty for this free
-software.  If the software is modified by someone else and passed on, we
-want its recipients to know that what they have is not the original, so
-that any problems introduced by others will not reflect on the original
-authors' reputations.
-
-  Finally, any free program is threatened constantly by software
-patents.  We wish to avoid the danger that redistributors of a free
-program will individually obtain patent licenses, in effect making the
-program proprietary.  To prevent this, we have made it clear that any
-patent must be licensed for everyone's free use or not licensed at all.
-
-  The precise terms and conditions for copying, distribution and
-modification follow.
-
-@iftex
-@c fakenode --- for prepinfo
-@unnumberedsec TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
-@end iftex
-@ifinfo
-@center TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
-@end ifinfo
-
-@enumerate
-@item
-This License applies to any program or other work which contains
-a notice placed by the copyright holder saying it may be distributed
-under the terms of this General Public License.  The ``Program'', below,
-refers to any such program or work, and a ``work based on the Program''
-means either the Program or any derivative work under copyright law:
-that is to say, a work containing the Program or a portion of it,
-either verbatim or with modifications and/or translated into another
-language.  (Hereinafter, translation is included without limitation in
-the term ``modification''.)  Each licensee is addressed as ``you''.
-
-Activities other than copying, distribution and modification are not
-covered by this License; they are outside its scope.  The act of
-running the Program is not restricted, and the output from the Program
-is covered only if its contents constitute a work based on the
-Program (independent of having been made by running the Program).
-Whether that is true depends on what the Program does.
-
-@item
-You may copy and distribute verbatim copies of the Program's
-source code as you receive it, in any medium, provided that you
-conspicuously and appropriately publish on each copy an appropriate
-copyright notice and disclaimer of warranty; keep intact all the
-notices that refer to this License and to the absence of any warranty;
-and give any other recipients of the Program a copy of this License
-along with the Program.
-
-You may charge a fee for the physical act of transferring a copy, and
-you may at your option offer warranty protection in exchange for a fee.
-
-@item
-You may modify your copy or copies of the Program or any portion
-of it, thus forming a work based on the Program, and copy and
-distribute such modifications or work under the terms of Section 1
-above, provided that you also meet all of these conditions:
-
-@enumerate a
-@item
-You must cause the modified files to carry prominent notices
-stating that you changed the files and the date of any change.
-
-@item
-You must cause any work that you distribute or publish, that in
-whole or in part contains or is derived from the Program or any
-part thereof, to be licensed as a whole at no charge to all third
-parties under the terms of this License.
-
-@item
-If the modified program normally reads commands interactively
-when run, you must cause it, when started running for such
-interactive use in the most ordinary way, to print or display an
-announcement including an appropriate copyright notice and a
-notice that there is no warranty (or else, saying that you provide
-a warranty) and that users may redistribute the program under
-these conditions, and telling the user how to view a copy of this
-License.  (Exception: if the Program itself is interactive but
-does not normally print such an announcement, your work based on
-the Program is not required to print an announcement.)
-@end enumerate
-
-These requirements apply to the modified work as a whole.  If
-identifiable sections of that work are not derived from the Program,
-and can be reasonably considered independent and separate works in
-themselves, then this License, and its terms, do not apply to those
-sections when you distribute them as separate works.  But when you
-distribute the same sections as part of a whole which is a work based
-on the Program, the distribution of the whole must be on the terms of
-this License, whose permissions for other licensees extend to the
-entire whole, and thus to each and every part regardless of who wrote it.
-
-Thus, it is not the intent of this section to claim rights or contest
-your rights to work written entirely by you; rather, the intent is to
-exercise the right to control the distribution of derivative or
-collective works based on the Program.
-
-In addition, mere aggregation of another work not based on the Program
-with the Program (or with a work based on the Program) on a volume of
-a storage or distribution medium does not bring the other work under
-the scope of this License.
-
-@item
-You may copy and distribute the Program (or a work based on it,
-under Section 2) in object code or executable form under the terms of
-Sections 1 and 2 above provided that you also do one of the following:
-
-@enumerate a
-@item
-Accompany it with the complete corresponding machine-readable
-source code, which must be distributed under the terms of Sections
-1 and 2 above on a medium customarily used for software interchange; or,
-
-@item
-Accompany it with a written offer, valid for at least three
-years, to give any third party, for a charge no more than your
-cost of physically performing source distribution, a complete
-machine-readable copy of the corresponding source code, to be
-distributed under the terms of Sections 1 and 2 above on a medium
-customarily used for software interchange; or,
-
-@item
-Accompany it with the information you received as to the offer
-to distribute corresponding source code.  (This alternative is
-allowed only for noncommercial distribution and only if you
-received the program in object code or executable form with such
-an offer, in accord with Subsection b above.)
-@end enumerate
-
-The source code for a work means the preferred form of the work for
-making modifications to it.  For an executable work, complete source
-code means all the source code for all modules it contains, plus any
-associated interface definition files, plus the scripts used to
-control compilation and installation of the executable.  However, as a
-special exception, the source code distributed need not include
-anything that is normally distributed (in either source or binary
-form) with the major components (compiler, kernel, and so on) of the
-operating system on which the executable runs, unless that component
-itself accompanies the executable.
-
-If distribution of executable or object code is made by offering
-access to copy from a designated place, then offering equivalent
-access to copy the source code from the same place counts as
-distribution of the source code, even though third parties are not
-compelled to copy the source along with the object code.
-
-@item
-You may not copy, modify, sublicense, or distribute the Program
-except as expressly provided under this License.  Any attempt
-otherwise to copy, modify, sublicense or distribute the Program is
-void, and will automatically terminate your rights under this License.
-However, parties who have received copies, or rights, from you under
-this License will not have their licenses terminated so long as such
-parties remain in full compliance.
-
-@item
-You are not required to accept this License, since you have not
-signed it.  However, nothing else grants you permission to modify or
-distribute the Program or its derivative works.  These actions are
-prohibited by law if you do not accept this License.  Therefore, by
-modifying or distributing the Program (or any work based on the
-Program), you indicate your acceptance of this License to do so, and
-all its terms and conditions for copying, distributing or modifying
-the Program or works based on it.
-
-@item
-Each time you redistribute the Program (or any work based on the
-Program), the recipient automatically receives a license from the
-original licensor to copy, distribute or modify the Program subject to
-these terms and conditions.  You may not impose any further
-restrictions on the recipients' exercise of the rights granted herein.
-You are not responsible for enforcing compliance by third parties to
-this License.
-
-@item
-If, as a consequence of a court judgment or allegation of patent
-infringement or for any other reason (not limited to patent issues),
-conditions are imposed on you (whether by court order, agreement or
-otherwise) that contradict the conditions of this License, they do not
-excuse you from the conditions of this License.  If you cannot
-distribute so as to satisfy simultaneously your obligations under this
-License and any other pertinent obligations, then as a consequence you
-may not distribute the Program at all.  For example, if a patent
-license would not permit royalty-free redistribution of the Program by
-all those who receive copies directly or indirectly through you, then
-the only way you could satisfy both it and this License would be to
-refrain entirely from distribution of the Program.
-
-If any portion of this section is held invalid or unenforceable under
-any particular circumstance, the balance of the section is intended to
-apply and the section as a whole is intended to apply in other
-circumstances.
-
-It is not the purpose of this section to induce you to infringe any
-patents or other property right claims or to contest validity of any
-such claims; this section has the sole purpose of protecting the
-integrity of the free software distribution system, which is
-implemented by public license practices.  Many people have made
-generous contributions to the wide range of software distributed
-through that system in reliance on consistent application of that
-system; it is up to the author/donor to decide if he or she is willing
-to distribute software through any other system and a licensee cannot
-impose that choice.
-
-This section is intended to make thoroughly clear what is believed to
-be a consequence of the rest of this License.
-
-@item
-If the distribution and/or use of the Program is restricted in
-certain countries either by patents or by copyrighted interfaces, the
-original copyright holder who places the Program under this License
-may add an explicit geographical distribution limitation excluding
-those countries, so that distribution is permitted only in or among
-countries not thus excluded.  In such case, this License incorporates
-the limitation as if written in the body of this License.
-
-@item
-The Free Software Foundation may publish revised and/or new versions
-of the General Public License from time to time.  Such new versions will
-be similar in spirit to the present version, but may differ in detail to
-address new problems or concerns.
-
-Each version is given a distinguishing version number.  If the Program
-specifies a version number of this License which applies to it and ``any
-later version'', you have the option of following the terms and conditions
-either of that version or of any later version published by the Free
-Software Foundation.  If the Program does not specify a version number of
-this License, you may choose any version ever published by the Free Software
-Foundation.
-
-@item
-If you wish to incorporate parts of the Program into other free
-programs whose distribution conditions are different, write to the author
-to ask for permission.  For software which is copyrighted by the Free
-Software Foundation, write to the Free Software Foundation; we sometimes
-make exceptions for this.  Our decision will be guided by the two goals
-of preserving the free status of all derivatives of our free software and
-of promoting the sharing and reuse of software generally.
-
-@iftex
-@c fakenode --- for prepinfo
-@heading NO WARRANTY
-@end iftex
-@ifinfo
-@center NO WARRANTY
-@end ifinfo
-
-@item
-BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
-FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
-OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
-PROVIDE THE PROGRAM ``AS IS'' WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
-OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
-MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
-TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
-PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
-REPAIR OR CORRECTION.
-
-@item
-IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
-REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
-INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
-OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
-TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
-YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
-PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
-POSSIBILITY OF SUCH DAMAGES.
-@end enumerate
-
-@iftex
-@c fakenode --- for prepinfo
-@heading END OF TERMS AND CONDITIONS
-@end iftex
-@ifinfo
-@center END OF TERMS AND CONDITIONS
-@end ifinfo
-
-@page
-@c fakenode --- for prepinfo
-@unnumberedsec How to Apply These Terms to Your New Programs
-
-  If you develop a new program, and you want it to be of the greatest
-possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these terms.
-
-  To do so, attach the following notices to the program.  It is safest
-to attach them to the start of each source file to most effectively
-convey the exclusion of warranty; and each file should have at least
-the ``copyright'' line and a pointer to where the full notice is found.
-
-@smallexample
-@var{one line to give the program's name and a brief idea of what it does.}
-Copyright (C) 19@var{yy}  @var{name of author}
-
-This program is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2 of the License, or
-(at your option) any later version.
-
-This program is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with this program; if not, write to the Free Software
-Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-@end smallexample
-
-Also add information on how to contact you by electronic and paper mail.
-
-If the program is interactive, make it output a short notice like this
-when it starts in an interactive mode:
-
-@smallexample
-Gnomovision version 69, Copyright (C) 19@var{yy} @var{name of author}
-Gnomovision comes with ABSOLUTELY NO WARRANTY; for details 
-type `show w'.
-This is free software, and you are welcome to redistribute it
-under certain conditions; type `show c' for details.
-@end smallexample
-
-The hypothetical commands @samp{show w} and @samp{show c} should show
-the appropriate parts of the General Public License.  Of course, the
-commands you use may be called something other than @samp{show w} and
-@samp{show c}; they could even be mouse-clicks or menu items---whatever
-suits your program.
-
-You should also get your employer (if you work as a programmer) or your
-school, if any, to sign a ``copyright disclaimer'' for the program, if
-necessary.  Here is a sample; alter the names:
-
-@smallexample
-Yoyodyne, Inc., hereby disclaims all copyright interest in the program
-`Gnomovision' (which makes passes at compilers) written by James Hacker.
-
-@var{signature of Ty Coon}, 1 April 1989
-Ty Coon, President of Vice
-@end smallexample
-
-This General Public License does not permit incorporating your program into
-proprietary programs.  If your program is a subroutine library, you may
-consider it more useful to permit linking proprietary applications with the
-library.  If this is what you want to do, use the GNU Library General
-Public License instead of this License.
-
-@node This Manual, Getting Started, Copying, Top
-@chapter Using this Manual
-@cindex manual, using this
-@cindex using this manual
-@cindex language, @code{awk}
-@cindex program, @code{awk}
-@cindex @code{awk} language
-@cindex @code{awk} program
-
-The term @code{awk} refers to a particular program, and to the language you
-use to tell this program what to do.  When we need to be careful, we call
-the program ``the @code{awk} utility'' and the language ``the @code{awk}
-language.''  The term @code{gawk} refers to a version of @code{awk} developed
-as part the GNU project.  The purpose of this manual is to explain
-both the
-@code{awk} language and how to run the @code{awk} utility.@refill
-
-While concentrating on the features of @code{gawk}, the manual will also
-attempt to describe important differences between @code{gawk} and other
-@code{awk} implementations.  In particular, any features that are not
-in the @sc{posix} standard for @code{awk} will be noted.  @refill
-
-The term @dfn{@code{awk} program} refers to a program written by you in
-the @code{awk} programming language.@refill
-
-@xref{Getting Started, ,Getting Started with @code{awk}}, for the bare
-essentials you need to know to start using @code{awk}.  
-
-Some useful ``one-liners'' are included to give you a feel for the
-@code{awk} language (@pxref{One-liners, ,Useful ``One-liners''}).
-
-@ignore
-@strong{I deleted four paragraphs here because they would confuse the
-beginner more than help him.  They mention terms such as ``field,''
-``pattern,'' ``action,'' ``built-in function'' which the beginner
-doesn't know.}
-
-@strong{If you can find a way to introduce several of these concepts here,
-enough to give the reader a map of what is to follow, that might
-be useful.  I'm not sure that can be done without taking up more
-space than ought to be used here.  There may be no way to win.}
-
-@strong{ADR: I'd like to tackle this in phase 2 of my editing.}
-@end ignore
-
-A sample @code{awk} program has been provided for you
-(@pxref{Sample Program}).@refill
-
-If you find terms that you aren't familiar with, try looking them
-up in the glossary (@pxref{Glossary}).@refill
-
-The entire @code{awk} language is summarized for quick reference in
-@ref{Gawk Summary, ,@code{gawk} Summary}.  Look there if you just need
-to refresh your memory about a particular feature.@refill
-
-Most of the time complete @code{awk} programs are used as examples, but in
-some of the more advanced sections, only the part of the @code{awk} program
-that illustrates the concept being described is shown.@refill
-
-@menu
-* Sample Data Files::           Sample data files for use in the @code{awk} 
-                                programs illustrated in this manual.
-@end menu
-
-@node Sample Data Files,  , This Manual, This Manual
-@section Data Files for the Examples
-
-@cindex input file, sample
-@cindex sample input file
-@cindex @file{BBS-list} file
-Many of the examples in this manual take their input from two sample
-data files.  The first, called @file{BBS-list}, represents a list of
-computer bulletin board systems together with information about those systems.
-The second data file, called @file{inventory-shipped}, contains
-information about shipments on a monthly basis.  Each line of these
-files is one @dfn{record}.
-
-In the file @file{BBS-list}, each record contains the name of a computer
-bulletin board, its phone number, the board's baud rate, and a code for
-the number of hours it is operational.  An @samp{A} in the last column
-means the board operates 24 hours a day.  A @samp{B} in the last
-column means the board operates evening and weekend hours, only.  A
-@samp{C} means the board operates only on weekends.
-
-@example
-aardvark     555-5553     1200/300          B
-alpo-net     555-3412     2400/1200/300     A
-barfly       555-7685     1200/300          A
-bites        555-1675     2400/1200/300     A
-camelot      555-0542     300               C
-core         555-2912     1200/300          C
-fooey        555-1234     2400/1200/300     B
-foot         555-6699     1200/300          B
-macfoo       555-6480     1200/300          A
-sdace        555-3430     2400/1200/300     A
-sabafoo      555-2127     1200/300          C
-@end example
-
-@cindex @file{inventory-shipped} file
-The second data file, called @file{inventory-shipped}, represents
-information about shipments during the year.  
-Each record contains the month of the year, the number
-of green crates shipped, the number of red boxes shipped, the number of
-orange bags shipped, and the number of blue packages shipped,
-respectively.  There are 16 entries, covering the 12 months of one year
-and 4 months of the next year.@refill
-
-@example
-Jan  13  25  15 115
-Feb  15  32  24 226
-Mar  15  24  34 228
-Apr  31  52  63 420
-May  16  34  29 208
-Jun  31  42  75 492
-Jul  24  34  67 436
-Aug  15  34  47 316
-Sep  13  55  37 277
-Oct  29  54  68 525
-Nov  20  87  82 577
-Dec  17  35  61 401
-
-Jan  21  36  64 620
-Feb  26  58  80 652
-Mar  24  75  70 495
-Apr  21  70  74 514
-@end example
-
-@ifinfo
-If you are reading this in GNU Emacs using Info, you can copy the regions
-of text showing these sample files into your own test files.  This way you
-can try out the examples shown in the remainder of this document.  You do
-this by using the command @kbd{M-x write-region} to copy text from the Info
-file into a file for use with @code{awk}
-(@xref{Misc File Ops, , , emacs, GNU Emacs Manual},
-for more information).  Using this information, create your own
-@file{BBS-list} and @file{inventory-shipped} files, and practice what you
-learn in this manual.
-@end ifinfo
-
-@node Getting Started, Reading Files, This Manual, Top
-@chapter Getting Started with @code{awk}
-@cindex script, definition of
-@cindex rule, definition of
-@cindex program, definition of
-@cindex basic function of @code{gawk}
-
-The basic function of @code{awk} is to search files for lines (or other
-units of text) that contain certain patterns.  When a line matches one
-of the patterns, @code{awk} performs specified actions on that line.
-@code{awk} keeps processing input lines in this way until the end of the
-input file is reached.@refill
-
-When you run @code{awk}, you specify an @code{awk} @dfn{program} which
-tells @code{awk} what to do.  The program consists of a series of
-@dfn{rules}.  (It may also contain @dfn{function definitions}, but that
-is an advanced feature, so we will ignore it for now.
-@xref{User-defined, ,User-defined Functions}.)  Each rule specifies one
-pattern to search for, and one action to perform when that pattern is found.
-
-Syntactically, a rule consists of a pattern followed by an action.  The
-action is enclosed in curly braces to separate it from the pattern.
-Rules are usually separated by newlines.  Therefore, an @code{awk}
-program looks like this:
-
-@example
-@var{pattern} @{ @var{action} @}
-@var{pattern} @{ @var{action} @}
-@dots{}
-@end example
-
-@menu
-* Very Simple::                 A very simple example.
-* Two Rules::                   A less simple one-line example with two rules.
-* More Complex::                A more complex example.
-* Running gawk::                How to run @code{gawk} programs; 
-                                includes command line syntax.
-* Comments::                    Adding documentation to @code{gawk} programs.
-* Statements/Lines::            Subdividing or combining statements into lines.
-* When::                        When to use @code{gawk} and 
-                                when to use other things.
-@end menu
-
-@node Very Simple, Two Rules, Getting Started, Getting Started
-@section A Very Simple Example
-
-@cindex @samp{print $0}
-The following command runs a simple @code{awk} program that searches the
-input file @file{BBS-list} for the string of characters: @samp{foo}.  (A
-string of characters is usually called, a @dfn{string}.
-The term @dfn{string} is perhaps based on similar usage in English, such
-as ``a string of pearls,'' or, ``a string of cars in a train.'')
-
-@example
-awk '/foo/ @{ print $0 @}' BBS-list
-@end example
-
-@noindent
-When lines containing @samp{foo} are found, they are printed, because
-@w{@samp{print $0}} means print the current line.  (Just @samp{print} by
-itself means the same thing, so we could have written that
-instead.)
-
-You will notice that slashes, @samp{/}, surround the string @samp{foo}
-in the actual @code{awk} program.  The slashes indicate that @samp{foo}
-is a pattern to search for.  This type of pattern is called a
-@dfn{regular expression}, and is covered in more detail later
-(@pxref{Regexp, ,Regular Expressions as Patterns}).  There are
-single-quotes around the @code{awk} program so that the shell won't
-interpret any of it as special shell characters.@refill
-
-Here is what this program prints:
-
-@example
-@group
-fooey        555-1234     2400/1200/300     B
-foot         555-6699     1200/300          B
-macfoo       555-6480     1200/300          A
-sabafoo      555-2127     1200/300          C
-@end group
-@end example
-
-@cindex action, default
-@cindex pattern, default
-@cindex default action
-@cindex default pattern
-In an @code{awk} rule, either the pattern or the action can be omitted,
-but not both.  If the pattern is omitted, then the action is performed
-for @emph{every} input line.  If the action is omitted, the default
-action is to print all lines that match the pattern.
-
-Thus, we could leave out the action (the @code{print} statement and the curly
-braces) in the above example, and the result would be the same: all
-lines matching the pattern @samp{foo} would be printed.  By comparison,
-omitting the @code{print} statement but retaining the curly braces makes an
-empty action that does nothing; then no lines would be printed.
-
-@node Two Rules, More Complex, Very Simple, Getting Started
-@section An Example with Two Rules
-@cindex how @code{awk} works
-
-The @code{awk} utility reads the input files one line at a
-time.  For each line, @code{awk} tries the patterns of each of the rules.
-If several patterns match then several actions are run, in the order in
-which they appear in the @code{awk} program.  If no patterns match, then
-no actions are run.
-
-After processing all the rules (perhaps none) that match the line,
-@code{awk} reads the next line (however,
-@pxref{Next Statement, ,The @code{next} Statement}).  This continues
-until the end of the file is reached.@refill
-
-For example, the @code{awk} program:
-
-@example
-/12/  @{ print $0 @}
-/21/  @{ print $0 @}
-@end example
-
-@noindent
-contains two rules.  The first rule has the string @samp{12} as the
-pattern and @samp{print $0} as the action.  The second rule has the
-string @samp{21} as the pattern and also has @samp{print $0} as the
-action.  Each rule's action is enclosed in its own pair of braces.
-
-This @code{awk} program prints every line that contains the string
-@samp{12} @emph{or} the string @samp{21}.  If a line contains both
-strings, it is printed twice, once by each rule.
-
-If we run this program on our two sample data files, @file{BBS-list} and
-@file{inventory-shipped}, as shown here:
-
-@example
-awk '/12/ @{ print $0 @}
-     /21/ @{ print $0 @}' BBS-list inventory-shipped
-@end example
-
-@noindent
-we get the following output:
-
-@example
-aardvark     555-5553     1200/300          B
-alpo-net     555-3412     2400/1200/300     A
-barfly       555-7685     1200/300          A
-bites        555-1675     2400/1200/300     A
-core         555-2912     1200/300          C
-fooey        555-1234     2400/1200/300     B
-foot         555-6699     1200/300          B
-macfoo       555-6480     1200/300          A
-sdace        555-3430     2400/1200/300     A
-sabafoo      555-2127     1200/300          C
-sabafoo      555-2127     1200/300          C
-Jan  21  36  64 620
-Apr  21  70  74 514
-@end example
-
-@noindent
-Note how the line in @file{BBS-list} beginning with @samp{sabafoo}
-was printed twice, once for each rule.
-
-@node More Complex, Running gawk, Two Rules, Getting Started
-@comment  node-name,  next,  previous,  up
-@section A More Complex Example
-
-Here is an example to give you an idea of what typical @code{awk}
-programs do.  This example shows how @code{awk} can be used to
-summarize, select, and rearrange the output of another utility.  It uses
-features that haven't been covered yet, so don't worry if you don't
-understand all the details.
-
-@example
-ls -l | awk '$5 == "Nov" @{ sum += $4 @}
-             END @{ print sum @}'
-@end example
-
-This command prints the total number of bytes in all the files in the
-current directory that were last modified in November (of any year).
-(In the C shell you would need to type a semicolon and then a backslash
-at the end of the first line; in a @sc{posix}-compliant shell, such as the
-Bourne shell or the Bourne-Again shell, you can type the example as shown.)
-
-The @w{@samp{ls -l}} part of this example is a command that gives you a 
-listing of the files in a directory, including file size and date.
-Its output looks like this:@refill
-
-@example
--rw-r--r--  1 close        1933 Nov  7 13:05 Makefile
--rw-r--r--  1 close       10809 Nov  7 13:03 gawk.h
--rw-r--r--  1 close         983 Apr 13 12:14 gawk.tab.h
--rw-r--r--  1 close       31869 Jun 15 12:20 gawk.y
--rw-r--r--  1 close       22414 Nov  7 13:03 gawk1.c
--rw-r--r--  1 close       37455 Nov  7 13:03 gawk2.c
--rw-r--r--  1 close       27511 Dec  9 13:07 gawk3.c
--rw-r--r--  1 close        7989 Nov  7 13:03 gawk4.c
-@end example
-
-@noindent
-The first field contains read-write permissions, the second field contains
-the number of links to the file, and the third field identifies the owner of
-the file.  The fourth field contains the size of the file in bytes.  The
-fifth, sixth, and seventh fields contain the month, day, and time,
-respectively, that the file was last modified.  Finally, the eighth field
-contains the name of the file.
-
-The @code{$5 == "Nov"} in our @code{awk} program is an expression that
-tests whether the fifth field of the output from @w{@samp{ls -l}}
-matches the string @samp{Nov}.  Each time a line has the string
-@samp{Nov} in its fifth field, the action @samp{@{ sum += $4 @}} is
-performed.  This adds the fourth field (the file size) to the variable
-@code{sum}.  As a result, when @code{awk} has finished reading all the
-input lines, @code{sum} is the sum of the sizes of files whose
-lines matched the pattern.  (This works because @code{awk} variables
-are automatically initialized to zero.)@refill
-
-After the last line of output from @code{ls} has been processed, the
-@code{END} rule is executed, and the value of @code{sum} is
-printed.  In this example, the value of @code{sum} would be 80600.@refill
-
-These more advanced @code{awk} techniques are covered in later sections
-(@pxref{Actions, ,Overview of Actions}).  Before you can move on to more
-advanced @code{awk} programming, you have to know how @code{awk} interprets
-your input and displays your output.  By manipulating fields and using
-@code{print} statements, you can produce some very useful and spectacular
-looking reports.@refill
-
-@node Running gawk, Comments, More Complex, Getting Started
-@section How to Run @code{awk} Programs
-
-@ignore
-Date: Mon, 26 Aug 91 09:48:10 +0200
-From: gatech!vsoc07.cern.ch!matheys (Jean-Pol Matheys (CERN - ECP Division))
-To: uunet.UU.NET!skeeve!arnold
-Subject: RE: status check
-
-The introduction of Chapter 2 (i.e. before 2.1) should include
-the whole of section 2.4  -  it's better to tell people how to run awk programs
-before giving any examples
-
-ADR --- he's right.  but for now, don't do this because the rest of the
-chapter would need some rewriting.
-@end ignore
-
-@cindex command line formats
-@cindex running @code{awk} programs
-There are several ways to run an @code{awk} program.  If the program is
-short, it is easiest to include it in the command that runs @code{awk},
-like this:
-
-@example
-awk '@var{program}' @var{input-file1} @var{input-file2} @dots{}
-@end example
-
-@noindent
-where @var{program} consists of a series of patterns and actions, as
-described earlier.
-
-When the program is long, it is usually more convenient to put it in a file
-and run it with a command like this:
-
-@example
-awk -f @var{program-file} @var{input-file1} @var{input-file2} @dots{}
-@end example
-
-@menu
-* One-shot::                    Running a short throw-away @code{awk} program.
-* Read Terminal::               Using no input files (input from 
-                                terminal instead).
-* Long::                        Putting permanent @code{awk} programs in files.
-* Executable Scripts::          Making self-contained @code{awk} programs.
-@end menu
-
-@node One-shot, Read Terminal, Running gawk, Running gawk
-@subsection One-shot Throw-away @code{awk} Programs
-
-Once you are familiar with @code{awk}, you will often type simple
-programs at the moment you want to use them.  Then you can write the
-program as the first argument of the @code{awk} command, like this:
-
-@example
-awk '@var{program}' @var{input-file1} @var{input-file2} @dots{}
-@end example
-
-@noindent
-where @var{program} consists of a series of @var{patterns} and
-@var{actions}, as described earlier.
-
-@cindex single quotes, why needed
-This command format instructs the shell to start @code{awk} and use the
-@var{program} to process records in the input file(s).  There are single
-quotes around @var{program} so that the shell doesn't interpret any
-@code{awk} characters as special shell characters.  They also cause the
-shell to treat all of @var{program} as a single argument for
-@code{awk} and allow @var{program} to be more than one line long.@refill
-
-This format is also useful for running short or medium-sized @code{awk}
-programs from shell scripts, because it avoids the need for a separate
-file for the @code{awk} program.  A self-contained shell script is more
-reliable since there are no other files to misplace.
-
-@node Read Terminal, Long, One-shot, Running gawk
-@subsection Running @code{awk} without Input Files
-
-@cindex standard input
-@cindex input, standard
-You can also run @code{awk} without any input files.  If you type the
-command line:@refill
-
-@example
-awk '@var{program}'
-@end example
-
-@noindent
-then @code{awk} applies the @var{program} to the @dfn{standard input},
-which usually means whatever you type on the terminal.  This continues
-until you indicate end-of-file by typing @kbd{Control-d}.
-
-For example, if you execute this command:
-
-@example
-awk '/th/'
-@end example
-
-@noindent
-whatever you type next is taken as data for that @code{awk}
-program.  If you go on to type the following data:
-
-@example
-Kathy
-Ben
-Tom
-Beth
-Seth
-Karen
-Thomas
-@kbd{Control-d}
-@end example
-
-@noindent
-then @code{awk} prints this output:
-
-@example
-Kathy
-Beth
-Seth
-@end example
-
-@noindent
-@cindex case sensitivity
-@cindex pattern, case sensitive
-as matching the pattern @samp{th}.  Notice that it did not recognize
-@samp{Thomas} as matching the pattern.  The @code{awk} language is
-@dfn{case sensitive}, and matches patterns exactly.  (However, you can
-override this with the variable @code{IGNORECASE}.
-@xref{Case-sensitivity, ,Case-sensitivity in Matching}.)
-
-@node Long, Executable Scripts, Read Terminal, Running gawk
-@subsection Running Long Programs
-
-@cindex running long programs
-@cindex @samp{-f} option
-@cindex program file
-@cindex file, @code{awk} program
-Sometimes your @code{awk} programs can be very long.  In this case it is
-more convenient to put the program into a separate file.  To tell
-@code{awk} to use that file for its program, you type:@refill
-
-@example
-awk -f @var{source-file} @var{input-file1} @var{input-file2} @dots{}
-@end example
-
-The @samp{-f} instructs the @code{awk} utility to get the @code{awk} program
-from the file @var{source-file}.  Any file name can be used for
-@var{source-file}.  For example, you could put the program:@refill
-
-@example
-/th/
-@end example
-
-@noindent
-into the file @file{th-prog}.  Then this command:
-
-@example
-awk -f th-prog
-@end example
-
-@noindent
-does the same thing as this one:
-
-@example
-awk '/th/'
-@end example
-
-@noindent
-which was explained earlier (@pxref{Read Terminal, ,Running @code{awk} without Input Files}).
-Note that you don't usually need single quotes around the file name that you
-specify with @samp{-f}, because most file names don't contain any of the shell's
-special characters.  Notice that in @file{th-prog}, the @code{awk}
-program did not have single quotes around it.  The quotes are only needed
-for programs that are provided on the @code{awk} command line.
-
-If you want to identify your @code{awk} program files clearly as such,
-you can add the extension @file{.awk} to the file name.  This doesn't
-affect the execution of the @code{awk} program, but it does make
-``housekeeping'' easier.
-
-@node Executable Scripts,  , Long, Running gawk
-@c node-name, next, previous, up
-@subsection Executable @code{awk} Programs
-@cindex executable scripts
-@cindex scripts, executable
-@cindex self contained programs
-@cindex program, self contained
-@cindex @samp{#!}
-
-Once you have learned @code{awk}, you may want to write self-contained
-@code{awk} scripts, using the @samp{#!} script mechanism.  You can do
-this on many Unix systems @footnote{The @samp{#!} mechanism works on
-Unix systems derived from Berkeley Unix, System V Release 4, and some System
-V Release 3 systems.} (and someday on GNU).@refill
-
-For example, you could create a text file named @file{hello}, containing
-the following (where @samp{BEGIN} is a feature we have not yet
-discussed):
-
-@example
-#! /bin/awk -f
-
-# a sample awk program
-BEGIN    @{ print "hello, world" @}
-@end example
-
-@noindent
-After making this file executable (with the @code{chmod} command), you
-can simply type:
-
-@example
-hello
-@end example
-
-@noindent
-at the shell, and the system will arrange to run @code{awk} @footnote{The
-line beginning with @samp{#!} lists the full pathname of an interpreter
-to be run, and an optional initial command line argument to pass to that
-interpreter.  The operating system then runs the interpreter with the given
-argument and the full argument list of the executed program.  The first argument
-in the list is the full pathname of the @code{awk} program.  The rest of the
-argument list will either be options to @code{awk}, or data files,
-or both.} as if you had typed:@refill
-
-@example
-awk -f hello
-@end example
-
-@noindent
-Self-contained @code{awk} scripts are useful when you want to write a
-program which users can invoke without knowing that the program is
-written in @code{awk}.
-
-@cindex shell scripts
-@cindex scripts, shell
-If your system does not support the @samp{#!} mechanism, you can get a
-similar effect using a regular shell script.  It would look something
-like this:
-
-@example
-: The colon makes sure this script is executed by the Bourne shell.
-awk '@var{program}' "$@@"
-@end example
-
-Using this technique, it is @emph{vital} to enclose the @var{program} in
-single quotes to protect it from interpretation by the shell.  If you
-omit the quotes, only a shell wizard can predict the results.
-
-The @samp{"$@@"} causes the shell to forward all the command line
-arguments to the @code{awk} program, without interpretation.  The first
-line, which starts with a colon, is used so that this shell script will
-work even if invoked by a user who uses the C shell.
-@c Someday: (See @cite{The Bourne Again Shell}, by ??.)
-
-@node Comments, Statements/Lines, Running gawk, Getting Started
-@section Comments in @code{awk} Programs
-@cindex @samp{#}
-@cindex comments
-@cindex use of comments
-@cindex documenting @code{awk} programs
-@cindex programs, documenting
-
-A @dfn{comment} is some text that is included in a program for the sake
-of human readers, and that is not really part of the program.  Comments
-can explain what the program does, and how it works.  Nearly all
-programming languages have provisions for comments, because programs are
-typically hard to understand without their extra help.
-
-In the @code{awk} language, a comment starts with the sharp sign
-character, @samp{#}, and continues to the end of the line.  The
-@code{awk} language ignores the rest of a line following a sharp sign.
-For example, we could have put the following into @file{th-prog}:@refill
-
-@smallexample
-# This program finds records containing the pattern @samp{th}.  This is how
-# you continue comments on additional lines.
-/th/
-@end smallexample
-
-You can put comment lines into keyboard-composed throw-away @code{awk}
-programs also, but this usually isn't very useful; the purpose of a
-comment is to help you or another person understand the program at
-a later time.@refill
-
-@node Statements/Lines, When, Comments, Getting Started
-@section @code{awk} Statements versus Lines
-
-Most often, each line in an @code{awk} program is a separate statement or
-separate rule, like this:
-
-@example
-awk '/12/  @{ print $0 @}
-     /21/  @{ print $0 @}' BBS-list inventory-shipped
-@end example
-
-But sometimes statements can be more than one line, and lines can
-contain several statements.  You can split a statement into multiple
-lines by inserting a newline after any of the following:@refill
-
-@example
-,    @{    ?    :    ||    &&    do    else
-@end example
-
-@noindent
-A newline at any other point is considered the end of the statement.
-(Splitting lines after @samp{?} and @samp{:} is a minor @code{gawk}
-extension.  The @samp{?} and @samp{:} referred to here is the 
-three operand conditional expression described in
-@ref{Conditional Exp, ,Conditional Expressions}.)@refill
-
-@cindex backslash continuation
-@cindex continuation of lines
-If you would like to split a single statement into two lines at a point
-where a newline would terminate it, you can @dfn{continue} it by ending the
-first line with a backslash character, @samp{\}.  This is allowed
-absolutely anywhere in the statement, even in the middle of a string or
-regular expression.  For example:
-
-@example
-awk '/This program is too long, so continue it\
- on the next line/ @{ print $1 @}'
-@end example
-
-@noindent
-We have generally not used backslash continuation in the sample programs in
-this manual.  Since in @code{gawk} there is no limit on the length of a line,
-it is never strictly necessary; it just makes programs prettier.  We have
-preferred to make them even more pretty by keeping the statements short.
-Backslash continuation is most useful when your @code{awk} program is in a
-separate source file, instead of typed in on the command line.  You should
-also note that many @code{awk} implementations are more picky about where
-you may use backslash continuation.  For maximal portability of your @code{awk}
-programs, it is best not to split your lines in the middle of a regular
-expression or a string.@refill
-
-@strong{Warning: backslash continuation does not work as described above
-with the C shell.}  Continuation with backslash works for @code{awk}
-programs in files, and also for one-shot programs @emph{provided} you
-are using a @sc{posix}-compliant shell, such as the Bourne shell or the
-Bourne-again shell.  But the C shell used on Berkeley Unix behaves
-differently!  There, you must use two backslashes in a row, followed by
-a newline.@refill
-
-@cindex multiple statements on one line
-When @code{awk} statements within one rule are short, you might want to put
-more than one of them on a line.  You do this by separating the statements
-with a semicolon, @samp{;}.
-This also applies to the rules themselves.
-Thus, the previous program could have been written:@refill
-
-@example
-/12/ @{ print $0 @} ; /21/ @{ print $0 @}
-@end example
-
-@noindent
-@strong{Note:} the requirement that rules on the same line must be
-separated with a semicolon is a recent change in the @code{awk}
-language; it was done for consistency with the treatment of statements
-within an action.
-
-@node When,  , Statements/Lines, Getting Started
-@section When to Use @code{awk}
-
-@cindex when to use @code{awk}
-@cindex applications of @code{awk}
-You might wonder how @code{awk} might be useful for you.  Using additional
-utility programs, more advanced patterns, field separators, arithmetic
-statements, and other selection criteria, you can produce much more
-complex output.  The @code{awk} language is very useful for producing
-reports from large amounts of raw data, such as summarizing information
-from the output of other utility programs like @code{ls}.  
-(@xref{More Complex, ,A More Complex Example}.)
-
-Programs written with @code{awk} are usually much smaller than they would
-be in other languages.  This makes @code{awk} programs easy to compose and
-use.  Often @code{awk} programs can be quickly composed at your terminal,
-used once, and thrown away.  Since @code{awk} programs are interpreted, you
-can avoid the usually lengthy edit-compile-test-debug cycle of software
-development.
-
-Complex programs have been written in @code{awk}, including a complete
-retargetable assembler for 8-bit microprocessors (@pxref{Glossary}, for
-more information) and a microcode assembler for a special purpose Prolog
-computer.  However, @code{awk}'s capabilities are strained by tasks of
-such complexity.
-
-If you find yourself writing @code{awk} scripts of more than, say, a few
-hundred lines, you might consider using a different programming
-language.  Emacs Lisp is a good choice if you need sophisticated string
-or pattern matching capabilities.  The shell is also good at string and
-pattern matching; in addition, it allows powerful use of the system
-utilities.  More conventional languages, such as C, C++, and Lisp, offer
-better facilities for system programming and for managing the complexity
-of large programs.  Programs in these languages may require more lines
-of source code than the equivalent @code{awk} programs, but they are
-easier to maintain and usually run more efficiently.@refill
-
-@node Reading Files, Printing, Getting Started, Top
-@chapter Reading Input Files
-
-@cindex reading files
-@cindex input
-@cindex standard input
-@vindex FILENAME
-In the typical @code{awk} program, all input is read either from the
-standard input (by default the keyboard, but often a pipe from another
-command) or from files whose names you specify on the @code{awk} command
-line.  If you specify input files, @code{awk} reads them in order, reading
-all the data from one before going on to the next.  The name of the current
-input file can be found in the built-in variable @code{FILENAME}
-(@pxref{Built-in Variables}).@refill
-
-The input is read in units called records, and processed by the
-rules one record at a time.  By default, each record is one line.  Each
-record is split automatically into fields, to make it more
-convenient for a rule to work on its parts.
-
-On rare occasions you will need to use the @code{getline} command,
-which can do explicit input from any number of files
-(@pxref{Getline, ,Explicit Input with @code{getline}}).@refill
-
-@menu
-* Records::                     Controlling how data is split into records.
-* Fields::                      An introduction to fields.
-* Non-Constant Fields::         Non-constant Field Numbers.
-* Changing Fields::             Changing the Contents of a Field.
-* Field Separators::            The field separator and how to change it.
-* Constant Size::               Reading constant width data.
-* Multiple Line::               Reading multi-line records.
-* Getline::                     Reading files under explicit program control
-                                using the @code{getline} function.
-* Close Input::                 Closing an input file (so you can read from
-                                the beginning once more).
-@end menu
-
-@node Records, Fields, Reading Files, Reading Files
-@section How Input is Split into Records
-
-@cindex record separator
-The @code{awk} language divides its input into records and fields.
-Records are separated by a character called the @dfn{record separator}.
-By default, the record separator is the newline character, defining
-a record to be a single line of text.@refill
-
-@iftex
-@cindex changing the record separator
-@end iftex
-@vindex RS
-Sometimes you may want to use a different character to separate your
-records.  You can use a different character by changing the built-in
-variable @code{RS}.  The value of @code{RS} is a string that says how
-to separate records; the default value is @code{"\n"}, the string containing
-just a newline character.  This is why records are, by default, single lines.
-
-@code{RS} can have any string as its value, but only the first character
-of the string is used as the record separator.  The other characters are
-ignored.  @code{RS} is exceptional in this regard; @code{awk} uses the
-full value of all its other built-in variables.@refill
-
-@ignore
-Someday this should be true!
-
-The value of @code{RS} is not limited to a one-character string.  It can
-be any regular expression (@pxref{Regexp, ,Regular Expressions as Patterns}).
-In general, each record
-ends at the next string that matches the regular expression; the next
-record starts at the end of the matching string.  This general rule is
-actually at work in the usual case, where @code{RS} contains just a
-newline: a record ends at the beginning of the next matching string (the
-next newline in the input) and the following record starts just after
-the end of this string (at the first character of the following line).
-The newline, since it matches @code{RS}, is not part of either record.@refill
-@end ignore
-
-You can change the value of @code{RS} in the @code{awk} program with the
-assignment operator, @samp{=} (@pxref{Assignment Ops, ,Assignment Expressions}).
-The new record-separator character should be enclosed in quotation marks to make
-a string constant.  Often the right time to do this is at the beginning
-of execution, before any input has been processed, so that the very
-first record will be read with the proper separator.  To do this, use
-the special @code{BEGIN} pattern
-(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}).  For
-example:@refill
-
-@example
-awk 'BEGIN @{ RS = "/" @} ; @{ print $0 @}' BBS-list
-@end example
-
-@noindent
-changes the value of @code{RS} to @code{"/"}, before reading any input.
-This is a string whose first character is a slash; as a result, records
-are separated by slashes.  Then the input file is read, and the second
-rule in the @code{awk} program (the action with no pattern) prints each
-record.  Since each @code{print} statement adds a newline at the end of
-its output, the effect of this @code{awk} program is to copy the input
-with each slash changed to a newline.
-
-Another way to change the record separator is on the command line,
-using the variable-assignment feature
-(@pxref{Command Line, ,Invoking @code{awk}}).@refill
-
-@example
-awk '@{ print $0 @}' RS="/" BBS-list
-@end example
-
-@noindent
-This sets @code{RS} to @samp{/} before processing @file{BBS-list}.
-
-Reaching the end of an input file terminates the current input record,
-even if the last character in the file is not the character in @code{RS}.
-
-@ignore
-@c merge the preceding paragraph and this stuff into one paragraph
-@c and put it in an `expert info' section.
-This produces correct behavior in the vast majority of cases, although
-the following (extreme) pipeline prints a surprising @samp{1}.  (There
-is one field, consisting of a newline.)
-
-@example
-echo | awk 'BEGIN @{ RS = "a" @} ; @{ print NF @}'
-@end example
-
-@end ignore
-
-The empty string, @code{""} (a string of no characters), has a special meaning
-as the value of @code{RS}: it means that records are separated only
-by blank lines.  @xref{Multiple Line, ,Multiple-Line Records}, for more details.
-
-@cindex number of records, @code{NR} or @code{FNR}
-@vindex NR
-@vindex FNR
-The @code{awk} utility keeps track of the number of records that have
-been read so far from the current input file.  This value is stored in a
-built-in variable called @code{FNR}.  It is reset to zero when a new
-file is started.  Another built-in variable, @code{NR}, is the total
-number of input records read so far from all files.  It starts at zero
-but is never automatically reset to zero.
-
-If you change the value of @code{RS} in the middle of an @code{awk} run,
-the new value is used to delimit subsequent records, but the record
-currently being processed (and records already processed) are not
-affected.
-
-@node Fields, Non-Constant Fields, Records, Reading Files
-@section Examining Fields
-
-@cindex examining fields
-@cindex fields
-@cindex accessing fields
-When @code{awk} reads an input record, the record is
-automatically separated or @dfn{parsed} by the interpreter into chunks
-called @dfn{fields}.  By default, fields are separated by whitespace,
-like words in a line.
-Whitespace in @code{awk} means any string of one or more spaces and/or
-tabs; other characters such as newline, formfeed, and so on, that are
-considered whitespace by other languages are @emph{not} considered
-whitespace by @code{awk}.@refill
-
-The purpose of fields is to make it more convenient for you to refer to
-these pieces of the record.  You don't have to use them---you can
-operate on the whole record if you wish---but fields are what make
-simple @code{awk} programs so powerful.
-
-@cindex @code{$} (field operator)
-@cindex operators, @code{$}
-To refer to a field in an @code{awk} program, you use a dollar-sign,
-@samp{$}, followed by the number of the field you want.  Thus, @code{$1}
-refers to the first field, @code{$2} to the second, and so on.  For
-example, suppose the following is a line of input:@refill
-
-@example
-This seems like a pretty nice example.
-@end example
-
-@noindent
-Here the first field, or @code{$1}, is @samp{This}; the second field, or
-@code{$2}, is @samp{seems}; and so on.  Note that the last field,
-@code{$7}, is @samp{example.}.  Because there is no space between the
-@samp{e} and the @samp{.}, the period is considered part of the seventh
-field.@refill
-
-No matter how many fields there are, the last field in a record can be
-represented by @code{$NF}.  So, in the example above, @code{$NF} would
-be the same as @code{$7}, which is @samp{example.}.  Why this works is
-explained below (@pxref{Non-Constant Fields, ,Non-constant Field Numbers}).
-If you try to refer to a field beyond the last one, such as @code{$8}
-when the record has only 7 fields, you get the empty string.@refill
-
-@vindex NF
-@cindex number of fields, @code{NF}
-Plain @code{NF}, with no @samp{$}, is a built-in variable whose value
-is the number of fields in the current record.
-
-@code{$0}, which looks like an attempt to refer to the zeroth field, is
-a special case: it represents the whole input record.  This is what you
-would use if you weren't interested in fields.
-
-Here are some more examples:
-
-@example
-awk '$1 ~ /foo/ @{ print $0 @}' BBS-list
-@end example
-
-@noindent
-This example prints each record in the file @file{BBS-list} whose first
-field contains the string @samp{foo}.  The operator @samp{~} is called a
-@dfn{matching operator} (@pxref{Comparison Ops, ,Comparison Expressions});
-it tests whether a string (here, the field @code{$1}) matches a given regular
-expression.@refill
-
-By contrast, the following example:
-
-@example
-awk '/foo/ @{ print $1, $NF @}' BBS-list
-@end example
-
-@noindent
-looks for @samp{foo} in @emph{the entire record} and prints the first
-field and the last field for each input record containing a
-match.@refill
-
-@node Non-Constant Fields, Changing Fields, Fields, Reading Files
-@section Non-constant Field Numbers
-
-The number of a field does not need to be a constant.  Any expression in
-the @code{awk} language can be used after a @samp{$} to refer to a
-field.  The value of the expression specifies the field number.  If the
-value is a string, rather than a number, it is converted to a number.
-Consider this example:@refill
-
-@example
-awk '@{ print $NR @}'
-@end example
-
-@noindent
-Recall that @code{NR} is the number of records read so far: 1 in the
-first record, 2 in the second, etc.  So this example prints the first
-field of the first record, the second field of the second record, and so
-on.  For the twentieth record, field number 20 is printed; most likely,
-the record has fewer than 20 fields, so this prints a blank line.
-
-Here is another example of using expressions as field numbers:
-
-@example
-awk '@{ print $(2*2) @}' BBS-list
-@end example
-
-The @code{awk} language must evaluate the expression @code{(2*2)} and use
-its value as the number of the field to print.  The @samp{*} sign
-represents multiplication, so the expression @code{2*2} evaluates to 4.
-The parentheses are used so that the multiplication is done before the
-@samp{$} operation; they are necessary whenever there is a binary
-operator in the field-number expression.  This example, then, prints the
-hours of operation (the fourth field) for every line of the file
-@file{BBS-list}.@refill
-
-If the field number you compute is zero, you get the entire record.
-Thus, @code{$(2-2)} has the same value as @code{$0}.  Negative field
-numbers are not allowed.
-
-The number of fields in the current record is stored in the built-in
-variable @code{NF} (@pxref{Built-in Variables}).  The expression
-@code{$NF} is not a special feature: it is the direct consequence of
-evaluating @code{NF} and using its value as a field number.
-
-@node Changing Fields, Field Separators, Non-Constant Fields, Reading Files
-@section Changing the Contents of a Field
-
-@cindex field, changing contents of
-@cindex changing contents of a field
-@cindex assignment to fields
-You can change the contents of a field as seen by @code{awk} within an
-@code{awk} program; this changes what @code{awk} perceives as the
-current input record.  (The actual input is untouched: @code{awk} never
-modifies the input file.)
-
-Consider this example:
-
-@smallexample
-awk '@{ $3 = $2 - 10; print $2, $3 @}' inventory-shipped
-@end smallexample
-
-@noindent
-The @samp{-} sign represents subtraction, so this program reassigns
-field three, @code{$3}, to be the value of field two minus ten,
-@code{$2 - 10}.  (@xref{Arithmetic Ops, ,Arithmetic Operators}.)
-Then field two, and the new value for field three, are printed.  
-
-In order for this to work, the text in field @code{$2} must make sense
-as a number; the string of characters must be converted to a number in
-order for the computer to do arithmetic on it.  The number resulting
-from the subtraction is converted back to a string of characters which
-then becomes field three.
-@xref{Conversion, ,Conversion of Strings and Numbers}.@refill
-
-When you change the value of a field (as perceived by @code{awk}), the
-text of the input record is recalculated to contain the new field where
-the old one was.  Therefore, @code{$0} changes to reflect the altered
-field.  Thus,
-
-@smallexample
-awk '@{ $2 = $2 - 10; print $0 @}' inventory-shipped
-@end smallexample
-
-@noindent
-prints a copy of the input file, with 10 subtracted from the second
-field of each line.
-
-You can also assign contents to fields that are out of range.  For
-example:
-
-@smallexample
-awk '@{ $6 = ($5 + $4 + $3 + $2) ; print $6 @}' inventory-shipped
-@end smallexample
-
-@noindent
-We've just created @code{$6}, whose value is the sum of fields
-@code{$2}, @code{$3}, @code{$4}, and @code{$5}.  The @samp{+} sign
-represents addition.  For the file @file{inventory-shipped}, @code{$6}
-represents the total number of parcels shipped for a particular month.
-
-Creating a new field changes the internal @code{awk} copy of the current
-input record---the value of @code{$0}.  Thus, if you do @samp{print $0}
-after adding a field, the record printed includes the new field, with
-the appropriate number of field separators between it and the previously
-existing fields.
-
-This recomputation affects and is affected by several features not yet
-discussed, in particular, the @dfn{output field separator}, @code{OFS},
-which is used to separate the fields (@pxref{Output Separators}), and
-@code{NF} (the number of fields; @pxref{Fields, ,Examining Fields}).
-For example, the value of @code{NF} is set to the number of the highest
-field you create.@refill
-
-Note, however, that merely @emph{referencing} an out-of-range field
-does @emph{not} change the value of either @code{$0} or @code{NF}.
-Referencing an out-of-range field merely produces a null string.  For
-example:@refill
-
-@smallexample
-if ($(NF+1) != "")
-    print "can't happen"
-else
-    print "everything is normal"
-@end smallexample
-
-@noindent
-should print @samp{everything is normal}, because @code{NF+1} is certain
-to be out of range.  (@xref{If Statement, ,The @code{if} Statement},
-for more information about @code{awk}'s @code{if-else} statements.)@refill
-
-It is important to note that assigning to a field will change the
-value of @code{$0}, but will not change the value of @code{NF},
-even when you assign the null string to a field.  For example:
-
-@smallexample
-echo a b c d | awk '@{ OFS = ":"; $2 = "" ; print ; print NF @}'
-@end smallexample
-
-@noindent
-prints
-
-@smallexample
-a::c:d
-4
-@end smallexample
-
-@noindent
-The field is still there, it just has an empty value.  You can tell
-because there are two colons in a row.
-
-@node Field Separators, Constant Size, Changing Fields, Reading Files
-@section Specifying how Fields are Separated
-@vindex FS
-@cindex fields, separating
-@cindex field separator, @code{FS}
-@cindex @samp{-F} option
-
-(This section is rather long; it describes one of the most fundamental
-operations in @code{awk}.  If you are a novice with @code{awk}, we
-recommend that you re-read this section after you have studied the
-section on regular expressions, @ref{Regexp, ,Regular Expressions as Patterns}.)
-
-The way @code{awk} splits an input record into fields is controlled by
-the @dfn{field separator}, which is a single character or a regular
-expression.  @code{awk} scans the input record for matches for the
-separator; the fields themselves are the text between the matches.  For
-example, if the field separator is @samp{oo}, then the following line:
-
-@smallexample
-moo goo gai pan
-@end smallexample
-
-@noindent
-would be split into three fields: @samp{m}, @samp{@ g} and @samp{@ gai@ 
-pan}.
-
-The field separator is represented by the built-in variable @code{FS}.
-Shell programmers take note!  @code{awk} does not use the name @code{IFS}
-which is used by the shell.@refill
-
-You can change the value of @code{FS} in the @code{awk} program with the
-assignment operator, @samp{=} (@pxref{Assignment Ops, ,Assignment Expressions}).
-Often the right time to do this is at the beginning of execution,
-before any input has been processed, so that the very first record
-will be read with the proper separator.  To do this, use the special
-@code{BEGIN} pattern
-(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}).
-For example, here we set the value of @code{FS} to the string
-@code{","}:@refill
-
-@smallexample
-awk 'BEGIN @{ FS = "," @} ; @{ print $2 @}'
-@end smallexample
-
-@noindent
-Given the input line,
-
-@smallexample
-John Q. Smith, 29 Oak St., Walamazoo, MI 42139
-@end smallexample
-
-@noindent
-this @code{awk} program extracts the string @samp{@ 29 Oak St.}.
-
-@cindex field separator, choice of
-@cindex regular expressions as field separators
-Sometimes your input data will contain separator characters that don't
-separate fields the way you thought they would.  For instance, the
-person's name in the example we've been using might have a title or
-suffix attached, such as @samp{John Q. Smith, LXIX}.  From input
-containing such a name:
-
-@smallexample
-John Q. Smith, LXIX, 29 Oak St., Walamazoo, MI 42139
-@end smallexample
-
-@noindent
-the previous sample program would extract @samp{@ LXIX}, instead of
-@samp{@ 29 Oak St.}.  If you were expecting the program to print the
-address, you would be surprised.  So choose your data layout and
-separator characters carefully to prevent such problems.
-
-As you know, by default, fields are separated by whitespace sequences
-(spaces and tabs), not by single spaces: two spaces in a row do not
-delimit an empty field.  The default value of the field separator is a
-string @w{@code{" "}} containing a single space.  If this value were
-interpreted in the usual way, each space character would separate
-fields, so two spaces in a row would make an empty field between them.
-The reason this does not happen is that a single space as the value of
-@code{FS} is a special case: it is taken to specify the default manner
-of delimiting fields.
-
-If @code{FS} is any other single character, such as @code{","}, then
-each occurrence of that character separates two fields.  Two consecutive
-occurrences delimit an empty field.  If the character occurs at the
-beginning or the end of the line, that too delimits an empty field.  The
-space character is the only single character which does not follow these
-rules.
-
-More generally, the value of @code{FS} may be a string containing any
-regular expression.  Then each match in the record for the regular
-expression separates fields.  For example, the assignment:@refill
-
-@smallexample
-FS = ", \t"
-@end smallexample
-
-@noindent
-makes every area of an input line that consists of a comma followed by a
-space and a tab, into a field separator.  (@samp{\t} stands for a
-tab.)@refill
-
-For a less trivial example of a regular expression, suppose you want
-single spaces to separate fields the way single commas were used above.
-You can set @code{FS} to @w{@code{"[@ ]"}}.  This regular expression
-matches a single space and nothing else.
-
-@c the following index entry is an overfull hbox.  --mew 30jan1992
-@cindex field separator: on command line
-@cindex command line, setting @code{FS} on
-@code{FS} can be set on the command line.  You use the @samp{-F} argument to
-do so.  For example:
-
-@smallexample
-awk -F, '@var{program}' @var{input-files}
-@end smallexample
-
-@noindent
-sets @code{FS} to be the @samp{,} character.  Notice that the argument uses
-a capital @samp{F}.  Contrast this with @samp{-f}, which specifies a file
-containing an @code{awk} program.  Case is significant in command options:
-the @samp{-F} and @samp{-f} options have nothing to do with each other.
-You can use both options at the same time to set the @code{FS} argument
-@emph{and} get an @code{awk} program from a file.@refill
-
-@c begin expert info
-The value used for the argument to @samp{-F} is processed in exactly the
-same way as assignments to the built-in variable @code{FS}.  This means that
-if the field separator contains special characters, they must be escaped
-appropriately.  For example, to use a @samp{\} as the field separator, you
-would have to type:
-
-@smallexample
-# same as FS = "\\" 
-awk -F\\\\ '@dots{}' files @dots{}
-@end smallexample
-
-@noindent
-Since @samp{\} is used for quoting in the shell, @code{awk} will see
-@samp{-F\\}.  Then @code{awk} processes the @samp{\\} for escape
-characters (@pxref{Constants, ,Constant Expressions}), finally yielding
-a single @samp{\} to be used for the field separator.
-@c end expert info
-
-As a special case, in compatibility mode
-(@pxref{Command Line, ,Invoking @code{awk}}), if the
-argument to @samp{-F} is @samp{t}, then @code{FS} is set to the tab
-character.  (This is because if you type @samp{-F\t}, without the quotes,
-at the shell, the @samp{\} gets deleted, so @code{awk} figures that you
-really want your fields to be separated with tabs, and not @samp{t}s.
-Use @samp{-v FS="t"} on the command line if you really do want to separate
-your fields with @samp{t}s.)@refill
-
-For example, let's use an @code{awk} program file called @file{baud.awk}
-that contains the pattern @code{/300/}, and the action @samp{print $1}.
-Here is the program:
-
-@smallexample
-/300/   @{ print $1 @}
-@end smallexample
-
-Let's also set @code{FS} to be the @samp{-} character, and run the
-program on the file @file{BBS-list}.  The following command prints a
-list of the names of the bulletin boards that operate at 300 baud and
-the first three digits of their phone numbers:@refill
-
-@smallexample
-awk -F- -f baud.awk BBS-list
-@end smallexample
-
-@noindent
-It produces this output:
-
-@smallexample
-aardvark     555
-alpo
-barfly       555
-bites        555
-camelot      555
-core         555
-fooey        555
-foot         555
-macfoo       555
-sdace        555
-sabafoo      555
-@end smallexample
-
-@noindent
-Note the second line of output.  If you check the original file, you will
-see that the second line looked like this:
-
-@smallexample
-alpo-net     555-3412     2400/1200/300     A
-@end smallexample
-
-The @samp{-} as part of the system's name was used as the field
-separator, instead of the @samp{-} in the phone number that was
-originally intended.  This demonstrates why you have to be careful in
-choosing your field and record separators.
-
-The following program searches the system password file, and prints
-the entries for users who have no password:
-
-@smallexample
-awk -F: '$2 == ""' /etc/passwd
-@end smallexample
-
-@noindent
-Here we use the @samp{-F} option on the command line to set the field
-separator.  Note that fields in @file{/etc/passwd} are separated by
-colons.  The second field represents a user's encrypted password, but if
-the field is empty, that user has no password.
-
-@c begin expert info
-According to the @sc{posix} standard, @code{awk} is supposed to behave
-as if each record is split into fields at the time that it is read.
-In particular, this means that you can change the value of @code{FS}
-after a record is read, but before any of the fields are referenced.
-The value of the fields (i.e. how they were split) should reflect the
-old value of @code{FS}, not the new one.
-
-However, many implementations of @code{awk} do not do this.  Instead,
-they defer splitting the fields until a field reference actually happens,
-using the @emph{current} value of @code{FS}!  This behavior can be difficult
-to diagnose. The following example illustrates the results of the two methods.
-(The @code{sed} command prints just the first line of @file{/etc/passwd}.)
-
-@smallexample
-sed 1q /etc/passwd | awk '@{ FS = ":" ; print $1 @}'
-@end smallexample
-
-@noindent
-will usually print
-
-@smallexample
-root
-@end smallexample
-
-@noindent
-on an incorrect implementation of @code{awk}, while @code{gawk}
-will print something like
-
-@smallexample
-root:nSijPlPhZZwgE:0:0:Root:/:
-@end smallexample
-@c end expert info
-
-@c begin expert info
-There is an important difference between the two cases of @samp{FS = @w{" "}}
-(a single blank) and @samp{FS = @w{"[ \t]+"}} (which is a regular expression
-matching one or more blanks or tabs).  For both values of @code{FS}, fields
-are separated by runs of blanks and/or tabs.  However, when the value of
-@code{FS} is @code{" "}, @code{awk} will strip leading and trailing whitespace
-from the record, and then decide where the fields are.  
-
-For example, the following expression prints @samp{b}:
-
-@smallexample
-echo ' a b c d ' | awk '@{ print $2 @}'
-@end smallexample
-
-@noindent
-However, the following prints @samp{a}:
-
-@smallexample
-echo ' a b c d ' | awk 'BEGIN @{ FS = "[ \t]+" @} ; @{ print $2 @}'
-@end smallexample
-
-@noindent
-In this case, the first field is null.
-
-The stripping of leading and trailing whitespace also comes into
-play whenever @code{$0} is recomputed.  For instance, this pipeline
-
-@smallexample
-echo '   a b c d' | awk '@{ print; $2 = $2; print @}'
-@end smallexample
-
-@noindent
-produces this output:
-
-@smallexample
-   a b c d
-a b c d
-@end smallexample
-
-@noindent
-The first @code{print} statement prints the record as it was read,
-with leading whitespace intact.  The assignment to @code{$2} rebuilds
-@code{$0} by concatenating @code{$1} through @code{$NF} together,
-separated by the value of @code{OFS}.  Since the leading whitespace
-was ignored when finding @code{$1}, it is not part of the new @code{$0}.
-Finally, the last @code{print} statement prints the new @code{$0}.
-@c end expert info
-
-The following table summarizes how fields are split, based on the
-value of @code{FS}.
-
-@table @code
-@item FS == " "
-Fields are separated by runs of whitespace.  Leading and trailing
-whitespace are ignored.  This is the default.
-
-@item FS == @var{any single character}
-Fields are separated by each occurrence of the character.  Multiple
-successive occurrences delimit empty fields, as do leading and
-trailing occurrences.
-
-@item FS == @var{regexp}
-Fields are separated by occurrences of characters that match @var{regexp}.
-Leading and trailing matches of @var{regexp} delimit empty fields.
-@end table
-
-@node Constant Size, Multiple Line, Field Separators, Reading Files
-@section Reading Fixed-width Data
-
-(This section discusses an advanced, experimental feature.  If you are
-a novice @code{awk} user, you may wish to skip it on the first reading.)
-
-@code{gawk} 2.13 introduced a new facility for dealing with fixed-width fields
-with no distinctive field separator.  Data of this nature arises typically
-in one of at least two ways:  the input for old FORTRAN programs where
-numbers are run together, and the output of programs that did not anticipate
-the use of their output as input for other programs.
-
-An example of the latter is a table where all the columns are lined up by
-the use of a variable number of spaces and @emph{empty fields are just
-spaces}.  Clearly, @code{awk}'s normal field splitting based on @code{FS}
-will not work well in this case.  (Although a portable @code{awk} program
-can use a series of @code{substr} calls on @code{$0}, this is awkward and
-inefficient for a large number of fields.)@refill
-
-The splitting of an input record into fixed-width fields is specified by
-assigning a string containing space-separated numbers to the built-in
-variable @code{FIELDWIDTHS}.  Each number specifies the width of the field
-@emph{including} columns between fields.  If you want to ignore the columns
-between fields, you can specify the width as a separate field that is
-subsequently ignored.
-
-The following data is the output of the @code{w} utility.  It is useful
-to illustrate the use of @code{FIELDWIDTHS}.
-
-@smallexample
- 10:06pm  up 21 days, 14:04,  23 users
-User     tty       login@  idle   JCPU   PCPU  what
-hzuo     ttyV0     8:58pm            9      5  vi p24.tex 
-hzang    ttyV3     6:37pm    50                -csh 
-eklye    ttyV5     9:53pm            7      1  em thes.tex 
-dportein ttyV6     8:17pm  1:47                -csh 
-gierd    ttyD3    10:00pm     1                elm 
-dave     ttyD4     9:47pm            4      4  w 
-brent    ttyp0    26Jun91  4:46  26:46   4:41  bash 
-dave     ttyq4    26Jun9115days     46     46  wnewmail 
-@end smallexample
-
-The following program takes the above input, converts the idle time to
-number of seconds and prints out the first two fields and the calculated
-idle time.  (This program uses a number of @code{awk} features that
-haven't been introduced yet.)@refill
-
-@smallexample
-BEGIN  @{ FIELDWIDTHS = "9 6 10 6 7 7 35" @}
-NR > 2 @{
-    idle = $4
-    sub(/^  */, "", idle)   # strip leading spaces
-    if (idle == "") idle = 0
-    if (idle ~ /:/) @{ split(idle, t, ":"); idle = t[1] * 60 + t[2] @}
-    if (idle ~ /days/) @{ idle *= 24 * 60 * 60 @}
- 
-    print $1, $2, idle
-@}
-@end smallexample
-
-Here is the result of running the program on the data:
-
-@smallexample
-hzuo      ttyV0  0
-hzang     ttyV3  50
-eklye     ttyV5  0
-dportein  ttyV6  107
-gierd     ttyD3  1
-dave      ttyD4  0
-brent     ttyp0  286
-dave      ttyq4  1296000
-@end smallexample
-
-Another (possibly more practical) example of fixed-width input data
-would be the input from a deck of balloting cards.  In some parts of
-the United States, voters make their choices by punching holes in computer
-cards.  These cards are then processed to count the votes for any particular
-candidate or on any particular issue.  Since a voter may choose not to
-vote on some issue, any column on the card may be empty.  An @code{awk}
-program for processing such data could use the @code{FIELDWIDTHS} feature
-to simplify reading the data.@refill
-
-@c of course, getting gawk to run on a system with card readers is
-@c another story!
-
-This feature is still experimental, and will likely evolve over time.
-
-@node Multiple Line, Getline, Constant Size, Reading Files
-@section Multiple-Line Records
-
-@cindex multiple line records
-@cindex input, multiple line records
-@cindex reading files, multiple line records
-@cindex records, multiple line
-In some data bases, a single line cannot conveniently hold all the
-information in one entry.  In such cases, you can use multi-line
-records.
-
-The first step in doing this is to choose your data format: when records
-are not defined as single lines, how do you want to define them?
-What should separate records?
-
-One technique is to use an unusual character or string to separate
-records.  For example, you could use the formfeed character (written
-@code{\f} in @code{awk}, as in C) to separate them, making each record
-a page of the file.  To do this, just set the variable @code{RS} to
-@code{"\f"} (a string containing the formfeed character).  Any
-other character could equally well be used, as long as it won't be part
-of the data in a record.@refill
-
-@ignore
-Another technique is to have blank lines separate records.  The string
-@code{"^\n+"} is a regular expression that matches any sequence of
-newlines starting at the beginning of a line---in other words, it
-matches a sequence of blank lines.  If you set @code{RS} to this string,
-a record always ends at the first blank line encountered.  In
-addition, a regular expression always matches the longest possible
-sequence when there is a choice.  So the next record doesn't start until
-the first nonblank line that follows---no matter how many blank lines
-appear in a row, they are considered one record-separator.
-@end ignore
-
-Another technique is to have blank lines separate records.  By a special
-dispensation, a null string as the value of @code{RS} indicates that
-records are separated by one or more blank lines.  If you set @code{RS}
-to the null string, a record always ends at the first blank line
-encountered.  And the next record doesn't start until the first nonblank
-line that follows---no matter how many blank lines appear in a row, they
-are considered one record-separator. (End of file is also considered
-a record separator.)@refill
-@c !!! This use of `end of file' is confusing.  Needs to be clarified.
-
-The second step is to separate the fields in the record.  One way to do
-this is to put each field on a separate line: to do this, just set the
-variable @code{FS} to the string @code{"\n"}.  (This simple regular
-expression matches a single newline.)
-
-Another way to separate fields is to divide each of the lines into fields
-in the normal manner.  This happens by default as a result of a special
-feature: when @code{RS} is set to the null string, the newline character
-@emph{always} acts as a field separator.  This is in addition to whatever
-field separations result from @code{FS}.
-
-The original motivation for this special exception was probably so that
-you get useful behavior in the default case (i.e., @w{@code{FS == " "}}).
-This feature can be a problem if you really don't want the
-newline character to separate fields, since there is no way to
-prevent it.  However, you can work around this by using the @code{split}
-function to break up the record manually
-(@pxref{String Functions, ,Built-in Functions for String Manipulation}).@refill
-
-@ignore
-Here are two ways to use records separated by blank lines and break each
-line into fields normally:
-
-@example
-awk 'BEGIN @{ RS = ""; FS = "[ \t\n]+" @} @{ print $1 @}' BBS-list
-
-@exdent @r{or}
-
-awk 'BEGIN @{ RS = "^\n+"; FS = "[ \t\n]+" @} @{ print $1 @}' BBS-list
-@end example
-@end ignore
-
-@ignore
-Here is how to use records separated by blank lines and break each
-line into fields normally:
-
-@example
-awk 'BEGIN @{ RS = ""; FS = "[ \t\n]+" @} ; @{ print $1 @}' BBS-list
-@end example
-@end ignore
-
-@node Getline, Close Input, Multiple Line, Reading Files
-@section Explicit Input with @code{getline}
-
-@findex getline
-@cindex input, explicit
-@cindex explicit input
-@cindex input, @code{getline} command
-@cindex reading files, @code{getline} command
-So far we have been getting our input files from @code{awk}'s main
-input stream---either the standard input (usually your terminal) or the
-files specified on the command line.  The @code{awk} language has a
-special built-in command called @code{getline} that
-can be used to read input under your explicit control.@refill
-
-This command is quite complex and should @emph{not} be used by
-beginners.  It is covered here because this is the chapter on input.
-The examples that follow the explanation of the @code{getline} command
-include material that has not been covered yet.  Therefore, come back
-and study the @code{getline} command @emph{after} you have reviewed the
-rest of this manual and have a good knowledge of how @code{awk} works.
-
-@vindex ERRNO
-@cindex differences: @code{gawk} and @code{awk}
-@code{getline} returns 1 if it finds a record, and 0 if the end of the
-file is encountered.  If there is some error in getting a record, such
-as a file that cannot be opened, then @code{getline} returns @minus{}1.
-In this case, @code{gawk} sets the variable @code{ERRNO} to a string
-describing the error that occurred.
-
-In the following examples, @var{command} stands for a string value that
-represents a shell command.
-
-@table @code
-@item getline
-The @code{getline} command can be used without arguments to read input
-from the current input file.  All it does in this case is read the next
-input record and split it up into fields.  This is useful if you've
-finished processing the current record, but you want to do some special
-processing @emph{right now} on the next record.  Here's an
-example:@refill
-
-@example
-awk '@{
-     if (t = index($0, "/*")) @{
-          if (t > 1)
-               tmp = substr($0, 1, t - 1)
-          else
-               tmp = ""
-          u = index(substr($0, t + 2), "*/")
-          while (u == 0) @{
-               getline
-               t = -1
-               u = index($0, "*/")
-          @}
-          if (u <= length($0) - 2)
-               $0 = tmp substr($0, t + u + 3)
-          else
-               $0 = tmp
-     @}
-     print $0
-@}'
-@end example
-
-This @code{awk} program deletes all C-style comments, @samp{/* @dots{}
-*/}, from the input.  By replacing the @samp{print $0} with other
-statements, you could perform more complicated processing on the
-decommented input, like searching for matches of a regular
-expression.  (This program has a subtle problem---can you spot it?)
-
-@c the program to remove comments doesn't work if one
-@c comment ends and another begins on the same line.  (Your
-@c idea for restart would be useful here).  --- brennan@boeing.com
-
-This form of the @code{getline} command sets @code{NF} (the number of
-fields; @pxref{Fields, ,Examining Fields}), @code{NR} (the number of
-records read so far; @pxref{Records, ,How Input is Split into Records}),
-@code{FNR} (the number of records read from this input file), and the
-value of @code{$0}.
-
-@strong{Note:} the new value of @code{$0} is used in testing
-the patterns of any subsequent rules.  The original value
-of @code{$0} that triggered the rule which executed @code{getline}
-is lost.  By contrast, the @code{next} statement reads a new record
-but immediately begins processing it normally, starting with the first
-rule in the program.  @xref{Next Statement, ,The @code{next} Statement}.
-
-@item getline @var{var}
-This form of @code{getline} reads a record into the variable @var{var}.
-This is useful when you want your program to read the next record from
-the current input file, but you don't want to subject the record to the
-normal input processing.
-
-For example, suppose the next line is a comment, or a special string,
-and you want to read it, but you must make certain that it won't trigger
-any rules.  This version of @code{getline} allows you to read that line
-and store it in a variable so that the main
-read-a-line-and-check-each-rule loop of @code{awk} never sees it.
-
-The following example swaps every two lines of input.  For example, given:
-
-@example
-wan
-tew
-free
-phore
-@end example
-
-@noindent
-it outputs:
-
-@example
-tew
-wan
-phore
-free
-@end example
-
-@noindent
-Here's the program:
-
-@example
-@group
-awk '@{
-     if ((getline tmp) > 0) @{
-          print tmp
-          print $0
-     @} else
-          print $0
-@}'
-@end group
-@end example
-
-The @code{getline} function used in this way sets only the variables
-@code{NR} and @code{FNR} (and of course, @var{var}).  The record is not
-split into fields, so the values of the fields (including @code{$0}) and
-the value of @code{NF} do not change.@refill
-
-@item getline < @var{file}
-@cindex input redirection
-@cindex redirection of input
-This form of the @code{getline} function takes its input from the file
-@var{file}.  Here @var{file} is a string-valued expression that
-specifies the file name.  @samp{< @var{file}} is called a @dfn{redirection}
-since it directs input to come from a different place.
-
-This form is useful if you want to read your input from a particular
-file, instead of from the main input stream.  For example, the following
-program reads its input record from the file @file{foo.input} when it
-encounters a first field with a value equal to 10 in the current input
-file.@refill
-
-@example
-awk '@{
-    if ($1 == 10) @{
-         getline < "foo.input"
-         print
-    @} else
-         print
-@}'
-@end example
-
-Since the main input stream is not used, the values of @code{NR} and
-@code{FNR} are not changed.  But the record read is split into fields in
-the normal manner, so the values of @code{$0} and other fields are
-changed.  So is the value of @code{NF}.
-
-This does not cause the record to be tested against all the patterns
-in the @code{awk} program, in the way that would happen if the record
-were read normally by the main processing loop of @code{awk}.  However
-the new record is tested against any subsequent rules, just as when
-@code{getline} is used without a redirection.
-
-@item getline @var{var} < @var{file}
-This form of the @code{getline} function takes its input from the file
-@var{file} and puts it in the variable @var{var}.  As above, @var{file}
-is a string-valued expression that specifies the file from which to read.
-
-In this version of @code{getline}, none of the built-in variables are
-changed, and the record is not split into fields.  The only variable
-changed is @var{var}.
-
-For example, the following program copies all the input files to the
-output, except for records that say @w{@samp{@@include @var{filename}}}.
-Such a record is replaced by the contents of the file
-@var{filename}.@refill
-
-@example
-awk '@{
-     if (NF == 2 && $1 == "@@include") @{
-          while ((getline line < $2) > 0)
-               print line
-          close($2)
-     @} else
-          print
-@}'
-@end example
-
-Note here how the name of the extra input file is not built into
-the program; it is taken from the data, from the second field on
-the @samp{@@include} line.@refill
-
-The @code{close} function is called to ensure that if two identical
-@samp{@@include} lines appear in the input, the entire specified file is
-included twice.  @xref{Close Input, ,Closing Input Files and Pipes}.@refill
-
-One deficiency of this program is that it does not process nested
-@samp{@@include} statements the way a true macro preprocessor would.
-
-@item @var{command} | getline
-You can @dfn{pipe} the output of a command into @code{getline}.  A pipe is
-simply a way to link the output of one program to the input of another.  In
-this case, the string @var{command} is run as a shell command and its output
-is piped into @code{awk} to be used as input.  This form of @code{getline}
-reads one record from the pipe.
-
-For example, the following program copies input to output, except for lines
-that begin with @samp{@@execute}, which are replaced by the output produced by
-running the rest of the line as a shell command:
-
-@example
-awk '@{
-     if ($1 == "@@execute") @{
-          tmp = substr($0, 10)
-          while ((tmp | getline) > 0)
-               print
-          close(tmp)
-     @} else
-          print
-@}'
-@end example
-
-@noindent
-The @code{close} function is called to ensure that if two identical
-@samp{@@execute} lines appear in the input, the command is run for
-each one.  @xref{Close Input, ,Closing Input Files and Pipes}.
-
-Given the input:
-
-@example
-foo
-bar
-baz
-@@execute who
-bletch
-@end example
-
-@noindent
-the program might produce:
-
-@example
-foo
-bar
-baz
-hack     ttyv0   Jul 13 14:22
-hack     ttyp0   Jul 13 14:23     (gnu:0)
-hack     ttyp1   Jul 13 14:23     (gnu:0)
-hack     ttyp2   Jul 13 14:23     (gnu:0)
-hack     ttyp3   Jul 13 14:23     (gnu:0)
-bletch
-@end example
-
-@noindent
-Notice that this program ran the command @code{who} and printed the result.
-(If you try this program yourself, you will get different results, showing
-you who is logged in on your system.)
-
-This variation of @code{getline} splits the record into fields, sets the
-value of @code{NF} and recomputes the value of @code{$0}.  The values of
-@code{NR} and @code{FNR} are not changed.
-
-@item @var{command} | getline @var{var}
-The output of the command @var{command} is sent through a pipe to
-@code{getline} and into the variable @var{var}.  For example, the
-following program reads the current date and time into the variable
-@code{current_time}, using the @code{date} utility, and then
-prints it.@refill
-
-@example
-awk 'BEGIN @{
-     "date" | getline current_time
-     close("date")
-     print "Report printed on " current_time
-@}'
-@end example
-
-In this version of @code{getline}, none of the built-in variables are
-changed, and the record is not split into fields.
-@end table
-
-@node Close Input,  , Getline, Reading Files
-@section Closing Input Files and Pipes
-@cindex closing input files and pipes
-@findex close
-
-If the same file name or the same shell command is used with
-@code{getline} more than once during the execution of an @code{awk}
-program, the file is opened (or the command is executed) only the first time.
-At that time, the first record of input is read from that file or command.
-The next time the same file or command is used in @code{getline}, another
-record is read from it, and so on.
-
-This implies that if you want to start reading the same file again from
-the beginning, or if you want to rerun a shell command (rather than
-reading more output from the command), you must take special steps.
-What you must do is use the @code{close} function, as follows:
-
-@example
-close(@var{filename})
-@end example
-
-@noindent
-or
-
-@example
-close(@var{command})
-@end example
-
-The argument @var{filename} or @var{command} can be any expression.  Its
-value must exactly equal the string that was used to open the file or
-start the command---for example, if you open a pipe with this:
-
-@example
-"sort -r names" | getline foo
-@end example
-
-@noindent
-then you must close it with this:
-
-@example
-close("sort -r names")
-@end example
-
-Once this function call is executed, the next @code{getline} from that
-file or command will reopen the file or rerun the command.
-
-@iftex
-@vindex ERRNO
-@cindex differences: @code{gawk} and @code{awk}
-@end iftex
-@code{close} returns a value of zero if the close succeeded.
-Otherwise, the value will be non-zero.
-In this case, @code{gawk} sets the variable @code{ERRNO} to a string
-describing the error that occurred.
-
-@node Printing, One-liners, Reading Files, Top
-@chapter Printing Output
-
-@cindex printing
-@cindex output
-One of the most common things that actions do is to output or @dfn{print}
-some or all of the input.  For simple output, use the @code{print}
-statement.  For fancier formatting use the @code{printf} statement.
-Both are described in this chapter.
-
-@menu
-* Print::                       The @code{print} statement.
-* Print Examples::              Simple examples of @code{print} statements.
-* Output Separators::           The output separators and how to change them.
-* OFMT::                        Controlling Numeric Output With @code{print}.
-* Printf::                      The @code{printf} statement.
-* Redirection::                 How to redirect output to multiple
-                                files and pipes.
-* Special Files::               File name interpretation in @code{gawk}.
-                                @code{gawk} allows access to 
-                                inherited file descriptors.
-@end menu
-
-@node Print, Print Examples, Printing, Printing
-@section The @code{print} Statement
-@cindex @code{print} statement
-
-The @code{print} statement does output with simple, standardized
-formatting.  You specify only the strings or numbers to be printed, in a
-list separated by commas.  They are output, separated by single spaces,
-followed by a newline.  The statement looks like this:
-
-@example
-print @var{item1}, @var{item2}, @dots{}
-@end example
-
-@noindent
-The entire list of items may optionally be enclosed in parentheses.  The
-parentheses are necessary if any of the item expressions uses a
-relational operator; otherwise it could be confused with a redirection
-(@pxref{Redirection, ,Redirecting Output of @code{print} and @code{printf}}).
-The relational operators are @samp{==},
-@samp{!=}, @samp{<}, @samp{>}, @samp{>=}, @samp{<=}, @samp{~} and
-@samp{!~} (@pxref{Comparison Ops, ,Comparison Expressions}).@refill
-
-The items printed can be constant strings or numbers, fields of the
-current record (such as @code{$1}), variables, or any @code{awk}
-expressions.  The @code{print} statement is completely general for
-computing @emph{what} values to print.  With two exceptions,
-you cannot specify @emph{how} to print them---how many
-columns, whether to use exponential notation or not, and so on.
-(@xref{Output Separators}, and
-@ref{OFMT, ,Controlling Numeric Output with @code{print}}.)
-For that, you need the @code{printf} statement
-(@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing}).@refill
-
-The simple statement @samp{print} with no items is equivalent to
-@samp{print $0}: it prints the entire current record.  To print a blank
-line, use @samp{print ""}, where @code{""} is the null, or empty,
-string.
-
-To print a fixed piece of text, use a string constant such as
-@w{@code{"Hello there"}} as one item.  If you forget to use the
-double-quote characters, your text will be taken as an @code{awk}
-expression, and you will probably get an error.  Keep in mind that a
-space is printed between any two items.
-
-Most often, each @code{print} statement makes one line of output.  But it
-isn't limited to one line.  If an item value is a string that contains a
-newline, the newline is output along with the rest of the string.  A
-single @code{print} can make any number of lines this way.
-
-@node Print Examples, Output Separators, Print, Printing
-@section Examples of @code{print} Statements
-
-Here is an example of printing a string that contains embedded newlines:
-
-@example
-awk 'BEGIN @{ print "line one\nline two\nline three" @}'
-@end example
-
-@noindent
-produces output like this:
-
-@example
-line one
-line two
-line three
-@end example
-
-Here is an example that prints the first two fields of each input record,
-with a space between them:
-
-@example
-awk '@{ print $1, $2 @}' inventory-shipped
-@end example
-
-@noindent
-Its output looks like this:
-
-@example
-Jan 13
-Feb 15
-Mar 15
-@dots{}
-@end example
-
-A common mistake in using the @code{print} statement is to omit the comma
-between two items.  This often has the effect of making the items run
-together in the output, with no space.  The reason for this is that
-juxtaposing two string expressions in @code{awk} means to concatenate
-them.  For example, without the comma:
-
-@example
-awk '@{ print $1 $2 @}' inventory-shipped
-@end example
-
-@noindent
-prints:
-
-@example
-@group
-Jan13
-Feb15
-Mar15
-@dots{}
-@end group
-@end example
-
-Neither example's output makes much sense to someone unfamiliar with the
-file @file{inventory-shipped}.  A heading line at the beginning would make
-it clearer.  Let's add some headings to our table of months (@code{$1}) and
-green crates shipped (@code{$2}).  We do this using the @code{BEGIN} pattern
-(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}) to force the headings to be printed only once:
-
-@example
-awk 'BEGIN @{  print "Month Crates"
-              print "----- ------" @}
-           @{  print $1, $2 @}' inventory-shipped
-@end example
-
-@noindent
-Did you already guess what happens?  This program prints the following:
-
-@example
-@group
-Month Crates
------ ------
-Jan 13
-Feb 15
-Mar 15
-@dots{}
-@end group
-@end example
-
-@noindent
-The headings and the table data don't line up!  We can fix this by printing
-some spaces between the two fields:
-
-@example
-awk 'BEGIN @{ print "Month Crates"
-             print "----- ------" @}
-           @{ print $1, "     ", $2 @}' inventory-shipped
-@end example
-
-You can imagine that this way of lining up columns can get pretty
-complicated when you have many columns to fix.  Counting spaces for two
-or three columns can be simple, but more than this and you can get
-``lost'' quite easily.  This is why the @code{printf} statement was
-created (@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing});
-one of its specialties is lining up columns of data.@refill
-
-@node Output Separators, OFMT, Print Examples, Printing
-@section Output Separators
-
-@cindex output field separator, @code{OFS}
-@vindex OFS
-@vindex ORS
-@cindex output record separator, @code{ORS}
-As mentioned previously, a @code{print} statement contains a list
-of items, separated by commas.  In the output, the items are normally
-separated by single spaces.  But they do not have to be spaces; a
-single space is only the default.  You can specify any string of
-characters to use as the @dfn{output field separator} by setting the
-built-in variable @code{OFS}.  The initial value of this variable
-is the string @w{@code{" "}}, that is, just a single space.@refill
-
-The output from an entire @code{print} statement is called an
-@dfn{output record}.  Each @code{print} statement outputs one output
-record and then outputs a string called the @dfn{output record separator}.
-The built-in variable @code{ORS} specifies this string.  The initial
-value of the variable is the string @code{"\n"} containing a newline
-character; thus, normally each @code{print} statement makes a separate line.
-
-You can change how output fields and records are separated by assigning
-new values to the variables @code{OFS} and/or @code{ORS}.  The usual
-place to do this is in the @code{BEGIN} rule
-(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}), so
-that it happens before any input is processed.  You may also do this
-with assignments on the command line, before the names of your input
-files.@refill
-
-The following example prints the first and second fields of each input
-record separated by a semicolon, with a blank line added after each
-line:@refill
-
-@example
-@group
-awk 'BEGIN @{ OFS = ";"; ORS = "\n\n" @}
-           @{ print $1, $2 @}'  BBS-list
-@end group
-@end example
-
-If the value of @code{ORS} does not contain a newline, all your output
-will be run together on a single line, unless you output newlines some
-other way.
-
-@node OFMT, Printf, Output Separators, Printing
-@section Controlling Numeric Output with @code{print}
-@vindex OFMT
-When you use the @code{print} statement to print numeric values,
-@code{awk} internally converts the number to a string of characters,
-and prints that string.  @code{awk} uses the @code{sprintf} function
-to do this conversion.  For now, it suffices to say that the @code{sprintf}
-function accepts a @dfn{format specification} that tells it how to format
-numbers (or strings), and that there are a number of different ways that
-numbers can be formatted.  The different format specifications are discussed
-more fully in
-@ref{Printf, ,Using @code{printf} Statements for Fancier Printing}.@refill
-
-The built-in variable @code{OFMT} contains the default format specification
-that @code{print} uses with @code{sprintf} when it wants to convert a
-number to a string for printing.  By supplying different format specifications
-as the value of @code{OFMT}, you can change how @code{print} will print
-your numbers.  As a brief example:
-
-@example
-@group
-awk 'BEGIN @{ OFMT = "%d"  # print numbers as integers
-             print 17.23 @}'
-@end group
-@end example
-
-@noindent
-will print @samp{17}.
-
-@node Printf, Redirection, OFMT, Printing
-@section Using @code{printf} Statements for Fancier Printing
-@cindex formatted output
-@cindex output, formatted
-
-If you want more precise control over the output format than
-@code{print} gives you, use @code{printf}.  With @code{printf} you can
-specify the width to use for each item, and you can specify various
-stylistic choices for numbers (such as what radix to use, whether to
-print an exponent, whether to print a sign, and how many digits to print
-after the decimal point).  You do this by specifying a string, called
-the @dfn{format string}, which controls how and where to print the other
-arguments.
-
-@menu
-* Basic Printf::                Syntax of the @code{printf} statement.
-* Control Letters::             Format-control letters.
-* Format Modifiers::            Format-specification modifiers.
-* Printf Examples::             Several examples.
-@end menu
-
-@node Basic Printf, Control Letters, Printf, Printf
-@subsection Introduction to the @code{printf} Statement
-
-@cindex @code{printf} statement, syntax of
-The @code{printf} statement looks like this:@refill
-
-@example
-printf @var{format}, @var{item1}, @var{item2}, @dots{}
-@end example
-
-@noindent
-The entire list of arguments may optionally be enclosed in parentheses.  The
-parentheses are necessary if any of the item expressions uses a
-relational operator; otherwise it could be confused with a redirection
-(@pxref{Redirection, ,Redirecting Output of @code{print} and @code{printf}}).
-The relational operators are @samp{==},
-@samp{!=}, @samp{<}, @samp{>}, @samp{>=}, @samp{<=}, @samp{~} and
-@samp{!~} (@pxref{Comparison Ops, ,Comparison Expressions}).@refill
-
-@cindex format string
-The difference between @code{printf} and @code{print} is the argument
-@var{format}.  This is an expression whose value is taken as a string; it
-specifies how to output each of the other arguments.  It is called
-the @dfn{format string}.
-
-The format string is the same as in the @sc{ansi} C library function
-@code{printf}.  Most of @var{format} is text to be output verbatim.
-Scattered among this text are @dfn{format specifiers}, one per item.
-Each format specifier says to output the next item at that place in the
-format.@refill
-
-The @code{printf} statement does not automatically append a newline to its
-output.  It outputs only what the format specifies.  So if you want
-a newline, you must include one in the format.  The output separator
-variables @code{OFS} and @code{ORS} have no effect on @code{printf}
-statements.@refill
-
-@node Control Letters, Format Modifiers, Basic Printf, Printf
-@subsection Format-Control Letters
-@cindex @code{printf}, format-control characters
-@cindex format specifier
-
-A format specifier starts with the character @samp{%} and ends with a
-@dfn{format-control letter}; it tells the @code{printf} statement how
-to output one item.  (If you actually want to output a @samp{%}, write
-@samp{%%}.)  The format-control letter specifies what kind of value to
-print.  The rest of the format specifier is made up of optional
-@dfn{modifiers} which are parameters such as the field width to use.@refill
-
-Here is a list of the format-control letters:
-
-@table @samp
-@item c
-This prints a number as an ASCII character.  Thus, @samp{printf "%c",
-65} outputs the letter @samp{A}.  The output for a string value is
-the first character of the string.
-
-@item d
-This prints a decimal integer.
-
-@item i
-This also prints a decimal integer.
-
-@item e
-This prints a number in scientific (exponential) notation.
-For example,
-
-@example
-printf "%4.3e", 1950
-@end example
-
-@noindent
-prints @samp{1.950e+03}, with a total of four significant figures of
-which three follow the decimal point.  The @samp{4.3} are @dfn{modifiers},
-discussed below.
-
-@item f
-This prints a number in floating point notation.
-
-@item g
-This prints a number in either scientific notation or floating point
-notation, whichever uses fewer characters.
-@ignore
-From: gatech!ames!elroy!cit-vax!EQL.Caltech.Edu!rankin (Pat Rankin)
-
-In the description of printf formats (p.43), the information for %g
-is incorrect (mainly, it's too much of an oversimplification).  It's
-wrong in the AWK book too, and in the gawk man page.  I suggested to
-David Trueman before 2.13 was released that the latter be revised, so
-that it matched gawk's behavior (rather than trying to change gawk to
-match the docs ;-).  The documented description is nice and simple, but
-it doesn't match the actual underlying behavior of %g in the various C
-run-time libraries that gawk relies on.  The precision value for g format
-is different than for f and e formats, so it's inaccurate to say 'g' is
-the shorter of 'e' or 'f'.  For 'g', precision represents the number of
-significant digits rather than the number of decimal places, and it has
-special rules about how to format numbers with range between 10E-1 and
-10E-4.  All in all, it's pretty messy, and I had to add that clumsy
-GFMT_WORKAROUND code because the VMS run-time library doesn't conform to
-the ANSI-C specifications.
-@end ignore
-
-@item o
-This prints an unsigned octal integer.
-
-@item s
-This prints a string.
-
-@item x
-This prints an unsigned hexadecimal integer.
-
-@item X
-This prints an unsigned hexadecimal integer.  However, for the values 10
-through 15, it uses the letters @samp{A} through @samp{F} instead of
-@samp{a} through @samp{f}.
-
-@item %
-This isn't really a format-control letter, but it does have a meaning
-when used after a @samp{%}: the sequence @samp{%%} outputs one
-@samp{%}.  It does not consume an argument.
-@end table
-
-@node Format Modifiers, Printf Examples, Control Letters, Printf
-@subsection Modifiers for @code{printf} Formats
-
-@cindex @code{printf}, modifiers
-@cindex modifiers (in format specifiers)
-A format specification can also include @dfn{modifiers} that can control
-how much of the item's value is printed and how much space it gets.  The
-modifiers come between the @samp{%} and the format-control letter.  Here
-are the possible modifiers, in the order in which they may appear:
-
-@table @samp
-@item -
-The minus sign, used before the width modifier, says to left-justify
-the argument within its specified width.  Normally the argument
-is printed right-justified in the specified width.  Thus,
-
-@example
-printf "%-4s", "foo"
-@end example
-
-@noindent
-prints @samp{foo }.
-
-@item @var{width}
-This is a number representing the desired width of a field.  Inserting any
-number between the @samp{%} sign and the format control character forces the
-field to be expanded to this width.  The default way to do this is to
-pad with spaces on the left.  For example,
-
-@example
-printf "%4s", "foo"
-@end example
-
-@noindent
-prints @samp{ foo}.
-
-The value of @var{width} is a minimum width, not a maximum.  If the item
-value requires more than @var{width} characters, it can be as wide as
-necessary.  Thus,
-
-@example
-printf "%4s", "foobar"
-@end example
-
-@noindent
-prints @samp{foobar}.
-
-Preceding the @var{width} with a minus sign causes the output to be
-padded with spaces on the right, instead of on the left.
-
-@item .@var{prec}
-This is a number that specifies the precision to use when printing.
-This specifies the number of digits you want printed to the right of the
-decimal point.  For a string, it specifies the maximum number of
-characters from the string that should be printed.
-@end table
-
-The C library @code{printf}'s dynamic @var{width} and @var{prec}
-capability (for example, @code{"%*.*s"}) is supported.  Instead of
-supplying explicit @var{width} and/or @var{prec} values in the format
-string, you pass them in the argument list.  For example:@refill
-
-@example
-w = 5
-p = 3
-s = "abcdefg"
-printf "<%*.*s>\n", w, p, s
-@end example
-
-@noindent
-is exactly equivalent to
-
-@example
-s = "abcdefg"
-printf "<%5.3s>\n", s
-@end example
-
-@noindent
-Both programs output @samp{@w{<@bullet{}@bullet{}abc>}}.  (We have
-used the bullet symbol ``@bullet{}'' to represent a space, to clearly
-show you that there are two spaces in the output.)@refill
-
-Earlier versions of @code{awk} did not support this capability.  You may
-simulate it by using concatenation to build up the format string,
-like so:@refill
-
-@example
-w = 5
-p = 3
-s = "abcdefg"
-printf "<%" w "." p "s>\n", s
-@end example
-
-@noindent
-This is not particularly easy to read, however.
-
-@node Printf Examples,  , Format Modifiers, Printf
-@subsection Examples of Using @code{printf}
-
-Here is how to use @code{printf} to make an aligned table:
-
-@example
-awk '@{ printf "%-10s %s\n", $1, $2 @}' BBS-list
-@end example
-
-@noindent
-prints the names of bulletin boards (@code{$1}) of the file
-@file{BBS-list} as a string of 10 characters, left justified.  It also
-prints the phone numbers (@code{$2}) afterward on the line.  This
-produces an aligned two-column table of names and phone numbers:@refill
-
-@example
-@group
-aardvark   555-5553
-alpo-net   555-3412
-barfly     555-7685
-bites      555-1675
-camelot    555-0542
-core       555-2912
-fooey      555-1234
-foot       555-6699
-macfoo     555-6480
-sdace      555-3430
-sabafoo    555-2127
-@end group
-@end example
-
-Did you notice that we did not specify that the phone numbers be printed
-as numbers?  They had to be printed as strings because the numbers are
-separated by a dash.  This dash would be interpreted as a minus sign if
-we had tried to print the phone numbers as numbers.  This would have led
-to some pretty confusing results.
-
-We did not specify a width for the phone numbers because they are the
-last things on their lines.  We don't need to put spaces after them.
-
-We could make our table look even nicer by adding headings to the tops
-of the columns.  To do this, use the @code{BEGIN} pattern
-(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns})
-to force the header to be printed only once, at the beginning of
-the @code{awk} program:@refill
-
-@example
-@group
-awk 'BEGIN @{ print "Name      Number"
-             print "----      ------" @}
-     @{ printf "%-10s %s\n", $1, $2 @}' BBS-list
-@end group
-@end example
-
-Did you notice that we mixed @code{print} and @code{printf} statements in
-the above example?  We could have used just @code{printf} statements to get
-the same results:
-
-@example
-@group
-awk 'BEGIN @{ printf "%-10s %s\n", "Name", "Number"
-             printf "%-10s %s\n", "----", "------" @}
-     @{ printf "%-10s %s\n", $1, $2 @}' BBS-list
-@end group
-@end example
-
-@noindent
-By outputting each column heading with the same format specification
-used for the elements of the column, we have made sure that the headings
-are aligned just like the columns.
-
-The fact that the same format specification is used three times can be
-emphasized by storing it in a variable, like this:
-
-@example
-awk 'BEGIN @{ format = "%-10s %s\n"
-             printf format, "Name", "Number"
-             printf format, "----", "------" @}
-     @{ printf format, $1, $2 @}' BBS-list
-@end example
-
-See if you can use the @code{printf} statement to line up the headings and
-table data for our @file{inventory-shipped} example covered earlier in the
-section on the @code{print} statement
-(@pxref{Print, ,The @code{print} Statement}).@refill
-
-@node Redirection, Special Files, Printf, Printing
-@section Redirecting Output of @code{print} and @code{printf}
-
-@cindex output redirection
-@cindex redirection of output
-So far we have been dealing only with output that prints to the standard
-output, usually your terminal.  Both @code{print} and @code{printf} can
-also send their output to other places.
-This is called @dfn{redirection}.@refill
-
-A redirection appears after the @code{print} or @code{printf} statement.
-Redirections in @code{awk} are written just like redirections in shell
-commands, except that they are written inside the @code{awk} program.
-
-@menu
-* File/Pipe Redirection::       Redirecting Output to Files and Pipes.
-* Close Output::                How to close output files and pipes.
-@end menu
-
-@node File/Pipe Redirection, Close Output, Redirection, Redirection
-@subsection Redirecting Output to Files and Pipes
-
-Here are the three forms of output redirection.  They are all shown for
-the @code{print} statement, but they work identically for @code{printf}
-also.@refill
-
-@table @code
-@item print @var{items} > @var{output-file}
-This type of redirection prints the items onto the output file
-@var{output-file}.  The file name @var{output-file} can be any
-expression.  Its value is changed to a string and then used as a
-file name (@pxref{Expressions, ,Expressions as Action Statements}).@refill
-
-When this type of redirection is used, the @var{output-file} is erased
-before the first output is written to it.  Subsequent writes do not
-erase @var{output-file}, but append to it.  If @var{output-file} does
-not exist, then it is created.@refill
-
-For example, here is how one @code{awk} program can write a list of
-BBS names to a file @file{name-list} and a list of phone numbers to a
-file @file{phone-list}.  Each output file contains one name or number
-per line.
-
-@smallexample
-awk '@{ print $2 > "phone-list"
-       print $1 > "name-list" @}' BBS-list
-@end smallexample
-
-@item print @var{items} >> @var{output-file}
-This type of redirection prints the items onto the output file
-@var{output-file}.  The difference between this and the
-single-@samp{>} redirection is that the old contents (if any) of
-@var{output-file} are not erased.  Instead, the @code{awk} output is
-appended to the file.
-
-@cindex pipes for output
-@cindex output, piping
-@item print @var{items} | @var{command}
-It is also possible to send output through a @dfn{pipe} instead of into a
-file.   This type of redirection opens a pipe to @var{command} and writes
-the values of @var{items} through this pipe, to another process created
-to execute @var{command}.@refill
-
-The redirection argument @var{command} is actually an @code{awk}
-expression.  Its value is converted to a string, whose contents give the
-shell command to be run.
-
-For example, this produces two files, one unsorted list of BBS names
-and one list sorted in reverse alphabetical order:
-
-@smallexample
-awk '@{ print $1 > "names.unsorted"
-       print $1 | "sort -r > names.sorted" @}' BBS-list
-@end smallexample
-
-Here the unsorted list is written with an ordinary redirection while
-the sorted list is written by piping through the @code{sort} utility.
-
-Here is an example that uses redirection to mail a message to a mailing
-list @samp{bug-system}.  This might be useful when trouble is encountered
-in an @code{awk} script run periodically for system maintenance.
-
-@smallexample
-report = "mail bug-system"
-print "Awk script failed:", $0 | report
-print "at record number", FNR, "of", FILENAME  | report
-close(report)
-@end smallexample
-
-We call the @code{close} function here because it's a good idea to close
-the pipe as soon as all the intended output has been sent to it.
-@xref{Close Output, ,Closing Output Files and Pipes}, for more information
-on this.  This example also illustrates the use of a variable to represent
-a @var{file} or @var{command}: it is not necessary to always
-use a string constant.  Using a variable is generally a good idea,
-since @code{awk} requires you to spell the string value identically
-every time.
-@end table
-
-Redirecting output using @samp{>}, @samp{>>}, or @samp{|} asks the system
-to open a file or pipe only if the particular @var{file} or @var{command}
-you've specified has not already been written to by your program, or if
-it has been closed since it was last written to.@refill
-
-@node Close Output,  , File/Pipe Redirection, Redirection
-@subsection Closing Output Files and Pipes
-@cindex closing output files and pipes
-@findex close
-
-When a file or pipe is opened, the file name or command associated with
-it is remembered by @code{awk} and subsequent writes to the same file or
-command are appended to the previous writes.  The file or pipe stays
-open until @code{awk} exits.  This is usually convenient.
-
-Sometimes there is a reason to close an output file or pipe earlier
-than that.  To do this, use the @code{close} function, as follows:
-
-@example
-close(@var{filename})
-@end example
-
-@noindent
-or
-
-@example
-close(@var{command})
-@end example
-
-The argument @var{filename} or @var{command} can be any expression.
-Its value must exactly equal the string used to open the file or pipe
-to begin with---for example, if you open a pipe with this:
-
-@example
-print $1 | "sort -r > names.sorted"
-@end example
-
-@noindent
-then you must close it with this:
-
-@example
-close("sort -r > names.sorted")
-@end example
-
-Here are some reasons why you might need to close an output file:
-
-@itemize @bullet
-@item
-To write a file and read it back later on in the same @code{awk}
-program.  Close the file when you are finished writing it; then
-you can start reading it with @code{getline}
-(@pxref{Getline, ,Explicit Input with @code{getline}}).@refill
-
-@item
-To write numerous files, successively, in the same @code{awk}
-program.  If you don't close the files, eventually you may exceed a
-system limit on the number of open files in one process.  So close
-each one when you are finished writing it.
-
-@item
-To make a command finish.  When you redirect output through a pipe,
-the command reading the pipe normally continues to try to read input
-as long as the pipe is open.  Often this means the command cannot
-really do its work until the pipe is closed.  For example, if you
-redirect output to the @code{mail} program, the message is not
-actually sent until the pipe is closed.
-
-@item
-To run the same program a second time, with the same arguments.
-This is not the same thing as giving more input to the first run!
-
-For example, suppose you pipe output to the @code{mail} program.  If you
-output several lines redirected to this pipe without closing it, they make
-a single message of several lines.  By contrast, if you close the pipe
-after each line of output, then each line makes a separate message.
-@end itemize
-
-@iftex
-@vindex ERRNO
-@cindex differences: @code{gawk} and @code{awk}
-@end iftex
-@code{close} returns a value of zero if the close succeeded.
-Otherwise, the value will be non-zero.
-In this case, @code{gawk} sets the variable @code{ERRNO} to a string
-describing the error that occurred.
-
-@node Special Files,  , Redirection, Printing
-@section Standard I/O Streams
-@cindex standard input
-@cindex standard output
-@cindex standard error output
-@cindex file descriptors
-
-Running programs conventionally have three input and output streams
-already available to them for reading and writing.  These are known as
-the @dfn{standard input}, @dfn{standard output}, and @dfn{standard error
-output}.  These streams are, by default, terminal input and output, but
-they are often redirected with the shell, via the @samp{<}, @samp{<<},
-@samp{>}, @samp{>>}, @samp{>&} and @samp{|} operators.  Standard error
-is used only for writing error messages; the reason we have two separate
-streams, standard output and standard error, is so that they can be
-redirected separately.
-
-@iftex
-@cindex differences: @code{gawk} and @code{awk}
-@end iftex
-In other implementations of @code{awk}, the only way to write an error
-message to standard error in an @code{awk} program is as follows:
-
-@smallexample
-print "Serious error detected!\n" | "cat 1>&2"
-@end smallexample
-
-@noindent
-This works by opening a pipeline to a shell command which can access the
-standard error stream which it inherits from the @code{awk} process.
-This is far from elegant, and is also inefficient, since it requires a
-separate process.  So people writing @code{awk} programs have often
-neglected to do this.  Instead, they have sent the error messages to the
-terminal, like this:
-
-@smallexample
-@group
-NF != 4 @{
-   printf("line %d skipped: doesn't have 4 fields\n", FNR) > "/dev/tty"
-@}
-@end group
-@end smallexample
-
-@noindent
-This has the same effect most of the time, but not always: although the
-standard error stream is usually the terminal, it can be redirected, and
-when that happens, writing to the terminal is not correct.  In fact, if
-@code{awk} is run from a background job, it may not have a terminal at all.
-Then opening @file{/dev/tty} will fail.
-
-@code{gawk} provides special file names for accessing the three standard
-streams.  When you redirect input or output in @code{gawk}, if the file name
-matches one of these special names, then @code{gawk} directly uses the
-stream it stands for.
-
-@cindex @file{/dev/stdin}
-@cindex @file{/dev/stdout}
-@cindex @file{/dev/stderr}
-@cindex @file{/dev/fd/}
-@table @file
-@item /dev/stdin
-The standard input (file descriptor 0).
-
-@item /dev/stdout
-The standard output (file descriptor 1).
-
-@item /dev/stderr
-The standard error output (file descriptor 2).
-
-@item /dev/fd/@var{N}
-The file associated with file descriptor @var{N}.  Such a file must have
-been opened by the program initiating the @code{awk} execution (typically
-the shell).  Unless you take special pains, only descriptors 0, 1 and 2
-are available.
-@end table
-
-The file names @file{/dev/stdin}, @file{/dev/stdout}, and @file{/dev/stderr}
-are aliases for @file{/dev/fd/0}, @file{/dev/fd/1}, and @file{/dev/fd/2},
-respectively, but they are more self-explanatory.
-
-The proper way to write an error message in a @code{gawk} program
-is to use @file{/dev/stderr}, like this:
-
-@smallexample
-NF != 4 @{
-  printf("line %d skipped: doesn't have 4 fields\n", FNR) > "/dev/stderr"
-@}
-@end smallexample
-
-@code{gawk} also provides special file names that give access to information
-about the running @code{gawk} process.  Each of these ``files'' provides
-a single record of information.  To read them more than once, you must
-first close them with the @code{close} function
-(@pxref{Close Input, ,Closing Input Files and Pipes}).
-The filenames are:
-
-@cindex @file{/dev/pid}
-@cindex @file{/dev/pgrpid}
-@cindex @file{/dev/ppid}
-@cindex @file{/dev/user}
-@table @file
-@item /dev/pid
-Reading this file returns the process ID of the current process,
-in decimal, terminated with a newline.
-
-@item  /dev/ppid
-Reading this file returns the parent process ID of the current process,
-in decimal, terminated with a newline.
-
-@item  /dev/pgrpid
-Reading this file returns the process group ID of the current process,
-in decimal, terminated with a newline.
-
-@item /dev/user
-Reading this file returns a single record terminated with a newline.
-The fields are separated with blanks.  The fields represent the
-following information:
-
-@table @code
-@item $1
-The value of the @code{getuid} system call.
-
-@item $2
-The value of the @code{geteuid} system call.
-
-@item $3
-The value of the @code{getgid} system call.
-
-@item $4
-The value of the @code{getegid} system call.
-@end table
-
-If there are any additional fields, they are the group IDs returned by
-@code{getgroups} system call.
-(Multiple groups may not be supported on all systems.)@refill
-@end table
-
-These special file names may be used on the command line as data
-files, as well as for I/O redirections within an @code{awk} program.
-They may not be used as source files with the @samp{-f} option.
-
-Recognition of these special file names is disabled if @code{gawk} is in
-compatibility mode (@pxref{Command Line, ,Invoking @code{awk}}).
-
-@quotation
-@strong{Caution}:  Unless your system actually has a @file{/dev/fd} directory
-(or any of the other above listed special files),
-the interpretation of these file names is done by @code{gawk} itself.
-For example, using @samp{/dev/fd/4} for output will actually write on
-file descriptor 4, and not on a new file descriptor that was @code{dup}'ed
-from file descriptor 4.  Most of the time this does not matter; however, it
-is important to @emph{not} close any of the files related to file descriptors
-0, 1, and 2.  If you do close one of these files, unpredictable behavior
-will result.
-@end quotation
-
-@node One-liners, Patterns, Printing, Top
-@chapter Useful ``One-liners''
-
-@cindex one-liners
-Useful @code{awk} programs are often short, just a line or two.  Here is a
-collection of useful, short programs to get you started.  Some of these
-programs contain constructs that haven't been covered yet.  The description
-of the program will give you a good idea of what is going on, but please
-read the rest of the manual to become an @code{awk} expert!
-
-@c Per suggestions from Michal Jaegermann
-@ifinfo
-Since you are reading this in Info, each line of the example code is
-enclosed in quotes, to represent text that you would type literally.
-The examples themselves represent shell commands that use single quotes
-to keep the shell from interpreting the contents of the program.
-When reading the examples, focus on the text between the open and close
-quotes.
-@end ifinfo
-
-@table @code
-@item awk '@{ if (NF > max) max = NF @}
-@itemx @ @ @ @ @ END @{ print max @}'
-This program prints the maximum number of fields on any input line.
-
-@item awk 'length($0) > 80'
-This program prints every line longer than 80 characters.  The sole
-rule has a relational expression as its pattern, and has no action (so the
-default action, printing the record, is used).
-
-@item awk 'NF > 0'
-This program prints every line that has at least one field.  This is an
-easy way to delete blank lines from a file (or rather, to create a new
-file similar to the old file but from which the blank lines have been
-deleted).
-
-@item awk '@{ if (NF > 0) print @}'
-This program also prints every line that has at least one field.  Here we
-allow the rule to match every line, then decide in the action whether
-to print.
-
-@item awk@ 'BEGIN@ @{@ for (i = 1; i <= 7; i++)
-@itemx @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ print int(101 * rand()) @}'
-This program prints 7 random numbers from 0 to 100, inclusive.
-
-@item ls -l @var{files} | awk '@{ x += $4 @} ; END @{ print "total bytes: " x @}'
-This program prints the total number of bytes used by @var{files}.
-
-@item expand@ @var{file}@ |@ awk@ '@{ if (x < length()) x = length() @}
-@itemx @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ END @{ print "maximum line length is " x @}'
-This program prints the maximum line length of @var{file}.  The input
-is piped through the @code{expand} program to change tabs into spaces,
-so the widths compared are actually the right-margin columns.
-
-@item awk 'BEGIN @{ FS = ":" @}
-@itemx @ @ @ @ @ @{ print $1 | "sort" @}' /etc/passwd
-This program prints a sorted list of the login names of all users.
-
-@item awk '@{ nlines++ @}
-@itemx @ @ @ @ @ END@ @{ print nlines @}'
-This programs counts lines in a file.
-
-@item awk 'END @{ print NR @}'
-This program also counts lines in a file, but lets @code{awk} do the work.
-
-@item awk '@{ print NR, $0 @}'
-This program adds line numbers to all its input files,
-similar to @samp{cat -n}.
-@end table
-
-@node Patterns, Actions, One-liners, Top
-@chapter Patterns
-@cindex pattern, definition of
-
-Patterns in @code{awk} control the execution of rules: a rule is
-executed when its pattern matches the current input record.  This
-chapter tells all about how to write patterns.
-
-@menu
-* Kinds of Patterns::           A list of all kinds of patterns.
-                                The following subsections describe 
-                                them in detail.
-* Regexp::                      Regular expressions such as @samp{/foo/}.
-* Comparison Patterns::         Comparison expressions such as @code{$1 > 10}.
-* Boolean Patterns::            Combining comparison expressions.
-* Expression Patterns::         Any expression can be used as a pattern.
-* Ranges::                      Pairs of patterns specify record ranges.
-* BEGIN/END::                   Specifying initialization and cleanup rules.
-* Empty::                       The empty pattern, which matches every record.
-@end menu
-
-@node Kinds of Patterns, Regexp, Patterns, Patterns
-@section Kinds of Patterns
-@cindex patterns, types of
-
-Here is a summary of the types of patterns supported in @code{awk}.
-@c At the next rewrite, check to see that this order matches the
-@c order in the text.  It might not matter to a reader, but it's good
-@c style.  Also, it might be nice to mention all the topics of sections
-@c that follow in this list; that way people can scan and know when to
-@c expect a specific topic.  Specifically please also make an entry
-@c for Boolean operators as patterns in the right place.  --mew
-
-@table @code
-@item /@var{regular expression}/
-A regular expression as a pattern.  It matches when the text of the
-input record fits the regular expression.
-(@xref{Regexp, ,Regular Expressions as Patterns}.)@refill
-
-@item @var{expression}
-A single expression.  It matches when its value, converted to a number,
-is nonzero (if a number) or nonnull (if a string).
-(@xref{Expression Patterns, ,Expressions as Patterns}.)@refill
-
-@item @var{pat1}, @var{pat2}
-A pair of patterns separated by a comma, specifying a range of records.
-(@xref{Ranges, ,Specifying Record Ranges with Patterns}.)
-
-@item BEGIN
-@itemx END
-Special patterns to supply start-up or clean-up information to
-@code{awk}.  (@xref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}.)
-
-@item @var{null}
-The empty pattern matches every input record.
-(@xref{Empty, ,The Empty Pattern}.)@refill
-@end table
-
-
-@node Regexp, Comparison Patterns, Kinds of Patterns, Patterns
-@section Regular Expressions as Patterns
-@cindex pattern, regular expressions
-@cindex regexp
-@cindex regular expressions as patterns
-
-A @dfn{regular expression}, or @dfn{regexp}, is a way of describing a
-class of strings.  A regular expression enclosed in slashes (@samp{/})
-is an @code{awk} pattern that matches every input record whose text
-belongs to that class.
-
-The simplest regular expression is a sequence of letters, numbers, or
-both.  Such a regexp matches any string that contains that sequence.
-Thus, the regexp @samp{foo} matches any string containing @samp{foo}.
-Therefore, the pattern @code{/foo/} matches any input record containing
-@samp{foo}.  Other kinds of regexps let you specify more complicated
-classes of strings.
-
-@menu
-* Regexp Usage::                How to Use Regular Expressions
-* Regexp Operators::            Regular Expression Operators
-* Case-sensitivity::            How to do case-insensitive matching.
-@end menu
-
-@node Regexp Usage, Regexp Operators, Regexp, Regexp
-@subsection How to Use Regular Expressions
-
-A regular expression can be used as a pattern by enclosing it in
-slashes.  Then the regular expression is matched against the
-entire text of each record.  (Normally, it only needs
-to match some part of the text in order to succeed.)  For example, this
-prints the second field of each record that contains @samp{foo} anywhere:
-
-@example
-awk '/foo/ @{ print $2 @}' BBS-list
-@end example
-
-@cindex regular expression matching operators
-@cindex string-matching operators
-@cindex operators, string-matching
-@cindex operators, regexp matching
-@cindex regexp search operators
-Regular expressions can also be used in comparison expressions.  Then
-you can specify the string to match against; it need not be the entire
-current input record.  These comparison expressions can be used as
-patterns or in @code{if}, @code{while}, @code{for}, and @code{do} statements.
-
-@table @code
-@item @var{exp} ~ /@var{regexp}/
-This is true if the expression @var{exp} (taken as a character string)
-is matched by @var{regexp}.  The following example matches, or selects,
-all input records with the upper-case letter @samp{J} somewhere in the
-first field:@refill
-
-@example
-awk '$1 ~ /J/' inventory-shipped
-@end example
-
-So does this:
-
-@example
-awk '@{ if ($1 ~ /J/) print @}' inventory-shipped
-@end example
-
-@item @var{exp} !~ /@var{regexp}/
-This is true if the expression @var{exp} (taken as a character string)
-is @emph{not} matched by @var{regexp}.  The following example matches,
-or selects, all input records whose first field @emph{does not} contain
-the upper-case letter @samp{J}:@refill
-
-@example
-awk '$1 !~ /J/' inventory-shipped
-@end example
-@end table
-
-@cindex computed regular expressions
-@cindex regular expressions, computed
-@cindex dynamic regular expressions
-The right hand side of a @samp{~} or @samp{!~} operator need not be a
-constant regexp (i.e., a string of characters between slashes).  It may
-be any expression.  The expression is evaluated, and converted if
-necessary to a string; the contents of the string are used as the
-regexp.  A regexp that is computed in this way is called a @dfn{dynamic
-regexp}.  For example:
-
-@example
-identifier_regexp = "[A-Za-z_][A-Za-z_0-9]+"
-$0 ~ identifier_regexp
-@end example
-
-@noindent
-sets @code{identifier_regexp} to a regexp that describes @code{awk}
-variable names, and tests if the input record matches this regexp.
-
-@node Regexp Operators, Case-sensitivity, Regexp Usage, Regexp
-@subsection Regular Expression Operators
-@cindex metacharacters
-@cindex regular expression metacharacters
-
-You can combine regular expressions with the following characters,
-called @dfn{regular expression operators}, or @dfn{metacharacters}, to
-increase the power and versatility of regular expressions.
-
-Here is a table of metacharacters.  All characters not listed in the
-table stand for themselves.
-
-@table @code
-@item ^
-This matches the beginning of the string or the beginning of a line
-within the string.  For example:
-
-@example
-^@@chapter
-@end example
-
-@noindent
-matches the @samp{@@chapter} at the beginning of a string, and can be used
-to identify chapter beginnings in Texinfo source files.
-
-@item $
-This is similar to @samp{^}, but it matches only at the end of a string
-or the end of a line within the string.  For example:
-
-@example
-p$
-@end example
-
-@noindent
-matches a record that ends with a @samp{p}.
-
-@item .
-This matches any single character except a newline.  For example:
-
-@example
-.P
-@end example
-
-@noindent
-matches any single character followed by a @samp{P} in a string.  Using
-concatenation we can make regular expressions like @samp{U.A}, which
-matches any three-character sequence that begins with @samp{U} and ends
-with @samp{A}.
-
-@item [@dots{}]
-This is called a @dfn{character set}.  It matches any one of the
-characters that are enclosed in the square brackets.  For example:
-
-@example
-[MVX]
-@end example
-
-@noindent
-matches any one of the characters @samp{M}, @samp{V}, or @samp{X} in a
-string.@refill
-
-Ranges of characters are indicated by using a hyphen between the beginning
-and ending characters, and enclosing the whole thing in brackets.  For
-example:@refill
-
-@example
-[0-9]
-@end example
-
-@noindent
-matches any digit.
-
-To include the character @samp{\}, @samp{]}, @samp{-} or @samp{^} in a
-character set, put a @samp{\} in front of it.  For example:
-
-@example
-[d\]]
-@end example
-
-@noindent
-matches either @samp{d}, or @samp{]}.@refill
-
-This treatment of @samp{\} is compatible with other @code{awk}
-implementations, and is also mandated by the @sc{posix} Command Language
-and Utilities standard.  The regular expressions in @code{awk} are a superset
-of the @sc{posix} specification for Extended Regular Expressions (EREs).
-@sc{posix} EREs are based on the regular expressions accepted by the
-traditional @code{egrep} utility.
-
-In @code{egrep} syntax, backslash is not syntactically special within
-square brackets.  This means that special tricks have to be used to
-represent the characters @samp{]}, @samp{-} and @samp{^} as members of a
-character set.
-
-In @code{egrep} syntax, to match @samp{-}, write it as @samp{---},
-which is a range containing only @w{@samp{-}.}  You may also give @samp{-}
-as the first or last character in the set.  To match @samp{^}, put it
-anywhere except as the first character of a set.  To match a @samp{]},
-make it the first character in the set.  For example:@refill
-
-@example
-[]d^]
-@end example
-
-@noindent
-matches either @samp{]}, @samp{d} or @samp{^}.@refill
-
-@item [^ @dots{}]
-This is a @dfn{complemented character set}.  The first character after
-the @samp{[} @emph{must} be a @samp{^}.  It matches any characters
-@emph{except} those in the square brackets (or newline).  For example:
-
-@example
-[^0-9]
-@end example
-
-@noindent
-matches any character that is not a digit.
-
-@item |
-This is the @dfn{alternation operator} and it is used to specify
-alternatives.  For example:
-
-@example
-^P|[0-9]
-@end example
-
-@noindent
-matches any string that matches either @samp{^P} or @samp{[0-9]}.  This
-means it matches any string that contains a digit or starts with @samp{P}.
-
-The alternation applies to the largest possible regexps on either side.
-@item (@dots{})
-Parentheses are used for grouping in regular expressions as in
-arithmetic.  They can be used to concatenate regular expressions
-containing the alternation operator, @samp{|}.
-
-@item *
-This symbol means that the preceding regular expression is to be
-repeated as many times as possible to find a match.  For example:
-
-@example
-ph*
-@end example
-
-@noindent
-applies the @samp{*} symbol to the preceding @samp{h} and looks for matches
-to one @samp{p} followed by any number of @samp{h}s.  This will also match
-just @samp{p} if no @samp{h}s are present.
-
-The @samp{*} repeats the @emph{smallest} possible preceding expression.
-(Use parentheses if you wish to repeat a larger expression.)  It finds
-as many repetitions as possible.  For example:
-
-@example
-awk '/\(c[ad][ad]*r x\)/ @{ print @}' sample
-@end example
-
-@noindent
-prints every record in the input containing a string of the form
-@samp{(car x)}, @samp{(cdr x)}, @samp{(cadr x)}, and so on.@refill
-
-@item +
-This symbol is similar to @samp{*}, but the preceding expression must be
-matched at least once.  This means that:
-
-@example
-wh+y
-@end example
-
-@noindent
-would match @samp{why} and @samp{whhy} but not @samp{wy}, whereas
-@samp{wh*y} would match all three of these strings.  This is a simpler
-way of writing the last @samp{*} example:
-
-@example
-awk '/\(c[ad]+r x\)/ @{ print @}' sample
-@end example
-
-@item ?
-This symbol is similar to @samp{*}, but the preceding expression can be
-matched once or not at all.  For example:
-
-@example
-fe?d
-@end example
-
-@noindent
-will match @samp{fed} and @samp{fd}, but nothing else.@refill
-
-@item \
-This is used to suppress the special meaning of a character when
-matching.  For example:
-
-@example
-\$
-@end example
-
-@noindent
-matches the character @samp{$}.
-
-The escape sequences used for string constants
-(@pxref{Constants, ,Constant Expressions}) are
-valid in regular expressions as well; they are also introduced by a
-@samp{\}.@refill
-@end table
-
-In regular expressions, the @samp{*}, @samp{+}, and @samp{?} operators have
-the highest precedence, followed by concatenation, and finally by @samp{|}.
-As in arithmetic, parentheses can change how operators are grouped.@refill
-
-@node Case-sensitivity,  , Regexp Operators, Regexp
-@subsection Case-sensitivity in Matching
-
-Case is normally significant in regular expressions, both when matching
-ordinary characters (i.e., not metacharacters), and inside character
-sets.  Thus a @samp{w} in a regular expression matches only a lower case
-@samp{w} and not an upper case @samp{W}.
-
-The simplest way to do a case-independent match is to use a character
-set: @samp{[Ww]}.  However, this can be cumbersome if you need to use it
-often; and it can make the regular expressions harder for humans to
-read.  There are two other alternatives that you might prefer.
-
-One way to do a case-insensitive match at a particular point in the
-program is to convert the data to a single case, using the
-@code{tolower} or @code{toupper} built-in string functions (which we
-haven't discussed yet;
-@pxref{String Functions, ,Built-in Functions for String Manipulation}).
-For example:@refill
-
-@example
-tolower($1) ~ /foo/  @{ @dots{} @}
-@end example
-
-@noindent
-converts the first field to lower case before matching against it.
-
-Another method is to set the variable @code{IGNORECASE} to a nonzero
-value (@pxref{Built-in Variables}).  When @code{IGNORECASE} is not zero,
-@emph{all} regexp operations ignore case.  Changing the value of
-@code{IGNORECASE} dynamically controls the case sensitivity of your
-program as it runs.  Case is significant by default because
-@code{IGNORECASE} (like most variables) is initialized to zero.
-
-@example
-x = "aB"
-if (x ~ /ab/) @dots{}   # this test will fail
-
-IGNORECASE = 1
-if (x ~ /ab/) @dots{}   # now it will succeed
-@end example
-
-In general, you cannot use @code{IGNORECASE} to make certain rules
-case-insensitive and other rules case-sensitive, because there is no way
-to set @code{IGNORECASE} just for the pattern of a particular rule.  To
-do this, you must use character sets or @code{tolower}.  However, one
-thing you can do only with @code{IGNORECASE} is turn case-sensitivity on
-or off dynamically for all the rules at once.@refill
-
-@code{IGNORECASE} can be set on the command line, or in a @code{BEGIN}
-rule.  Setting @code{IGNORECASE} from the command line is a way to make
-a program case-insensitive without having to edit it.
-
-The value of @code{IGNORECASE} has no effect if @code{gawk} is in
-compatibility mode (@pxref{Command Line, ,Invoking @code{awk}}).
-Case is always significant in compatibility mode.@refill
-
-@node Comparison Patterns, Boolean Patterns, Regexp, Patterns
-@section Comparison Expressions as Patterns
-@cindex comparison expressions as patterns
-@cindex pattern, comparison expressions
-@cindex relational operators
-@cindex operators, relational
-
-@dfn{Comparison patterns} test relationships such as equality between
-two strings or numbers.  They are a special case of expression patterns
-(@pxref{Expression Patterns, ,Expressions as Patterns}).  They are written
-with @dfn{relational operators}, which are a superset of those in C.
-Here is a table of them:@refill
-
-@table @code
-@item @var{x} < @var{y}
-True if @var{x} is less than @var{y}.
-
-@item @var{x} <= @var{y}
-True if @var{x} is less than or equal to @var{y}.
-
-@item @var{x} > @var{y}
-True if @var{x} is greater than @var{y}.
-
-@item @var{x} >= @var{y}
-True if @var{x} is greater than or equal to @var{y}.
-
-@item @var{x} == @var{y}
-True if @var{x} is equal to @var{y}.
-
-@item @var{x} != @var{y}
-True if @var{x} is not equal to @var{y}.
-
-@item @var{x} ~ @var{y}
-True if @var{x} matches the regular expression described by @var{y}.
-
-@item @var{x} !~ @var{y}
-True if @var{x} does not match the regular expression described by @var{y}.
-@end table
-
-The operands of a relational operator are compared as numbers if they
-are both numbers.  Otherwise they are converted to, and compared as,
-strings (@pxref{Conversion, ,Conversion of Strings and Numbers},
-for the detailed rules).  Strings are compared by comparing the first
-character of each, then the second character of each,
-and so on, until there is a difference.  If the two strings are equal until
-the shorter one runs out, the shorter one is considered to be less than the
-longer one.  Thus, @code{"10"} is less than @code{"9"}, and @code{"abc"}
-is less than @code{"abcd"}.@refill
-
-The left operand of the @samp{~} and @samp{!~} operators is a string.
-The right operand is either a constant regular expression enclosed in
-slashes (@code{/@var{regexp}/}), or any expression, whose string value
-is used as a dynamic regular expression
-(@pxref{Regexp Usage, ,How to Use Regular Expressions}).@refill
-
-The following example prints the second field of each input record
-whose first field is precisely @samp{foo}.
-
-@example
-awk '$1 == "foo" @{ print $2 @}' BBS-list
-@end example
-
-@noindent
-Contrast this with the following regular expression match, which would
-accept any record with a first field that contains @samp{foo}:
-
-@example
-awk '$1 ~ "foo" @{ print $2 @}' BBS-list
-@end example
-
-@noindent
-or, equivalently, this one:
-
-@example
-awk '$1 ~ /foo/ @{ print $2 @}' BBS-list
-@end example
-
-@node Boolean Patterns, Expression Patterns, Comparison Patterns, Patterns
-@section Boolean Operators and Patterns
-@cindex patterns, boolean
-@cindex boolean patterns
-
-A @dfn{boolean pattern} is an expression which combines other patterns
-using the @dfn{boolean operators} ``or'' (@samp{||}), ``and''
-(@samp{&&}), and ``not'' (@samp{!}).  Whether the boolean pattern
-matches an input record depends on whether its subpatterns match.
-
-For example, the following command prints all records in the input file
-@file{BBS-list} that contain both @samp{2400} and @samp{foo}.@refill
-
-@example
-awk '/2400/ && /foo/' BBS-list
-@end example
-
-The following command prints all records in the input file
-@file{BBS-list} that contain @emph{either} @samp{2400} or @samp{foo}, or
-both.@refill
-
-@example
-awk '/2400/ || /foo/' BBS-list
-@end example
-
-The following command prints all records in the input file
-@file{BBS-list} that do @emph{not} contain the string @samp{foo}.
-
-@example
-awk '! /foo/' BBS-list
-@end example
-
-Note that boolean patterns are a special case of expression patterns
-(@pxref{Expression Patterns, ,Expressions as Patterns}); they are
-expressions that use the boolean operators.
-@xref{Boolean Ops, ,Boolean Expressions}, for complete information
-on the boolean operators.@refill
-
-The subpatterns of a boolean pattern can be constant regular
-expressions, comparisons, or any other @code{awk} expressions.  Range
-patterns are not expressions, so they cannot appear inside boolean
-patterns.  Likewise, the special patterns @code{BEGIN} and @code{END},
-which never match any input record, are not expressions and cannot
-appear inside boolean patterns.
-
-@node Expression Patterns, Ranges, Boolean Patterns, Patterns
-@section Expressions as Patterns
-
-Any @code{awk} expression is also valid as an @code{awk} pattern.
-Then the pattern ``matches'' if the expression's value is nonzero (if a
-number) or nonnull (if a string).
-
-The expression is reevaluated each time the rule is tested against a new
-input record.  If the expression uses fields such as @code{$1}, the
-value depends directly on the new input record's text; otherwise, it
-depends only on what has happened so far in the execution of the
-@code{awk} program, but that may still be useful.
-
-Comparison patterns are actually a special case of this.  For
-example, the expression @code{$5 == "foo"} has the value 1 when the
-value of @code{$5} equals @code{"foo"}, and 0 otherwise; therefore, this
-expression as a pattern matches when the two values are equal.
-
-Boolean patterns are also special cases of expression patterns.
-
-A constant regexp as a pattern is also a special case of an expression
-pattern.  @code{/foo/} as an expression has the value 1 if @samp{foo}
-appears in the current input record; thus, as a pattern, @code{/foo/}
-matches any record containing @samp{foo}.
-
-Other implementations of @code{awk} that are not yet @sc{posix} compliant
-are less general than @code{gawk}: they allow comparison expressions, and
-boolean combinations thereof (optionally with parentheses), but not
-necessarily other kinds of expressions.
-
-@node Ranges, BEGIN/END, Expression Patterns, Patterns
-@section Specifying Record Ranges with Patterns
-
-@cindex range pattern
-@cindex patterns, range
-A @dfn{range pattern} is made of two patterns separated by a comma, of
-the form @code{@var{begpat}, @var{endpat}}.  It matches ranges of
-consecutive input records.  The first pattern @var{begpat} controls
-where the range begins, and the second one @var{endpat} controls where
-it ends.  For example,@refill
-
-@example
-awk '$1 == "on", $1 == "off"'
-@end example
-
-@noindent
-prints every record between @samp{on}/@samp{off} pairs, inclusive.
-
-A range pattern starts out by matching @var{begpat}
-against every input record; when a record matches @var{begpat}, the
-range pattern becomes @dfn{turned on}.  The range pattern matches this
-record.  As long as it stays turned on, it automatically matches every
-input record read.  It also matches @var{endpat} against
-every input record; when that succeeds, the range pattern is turned
-off again for the following record.  Now it goes back to checking
-@var{begpat} against each record.
-
-The record that turns on the range pattern and the one that turns it
-off both match the range pattern.  If you don't want to operate on
-these records, you can write @code{if} statements in the rule's action
-to distinguish them.
-
-It is possible for a pattern to be turned both on and off by the same
-record, if both conditions are satisfied by that record.  Then the action is
-executed for just that record.
-
-@node BEGIN/END, Empty, Ranges, Patterns
-@section @code{BEGIN} and @code{END} Special Patterns
-
-@cindex @code{BEGIN} special pattern
-@cindex patterns, @code{BEGIN}
-@cindex @code{END} special pattern
-@cindex patterns, @code{END}
-@code{BEGIN} and @code{END} are special patterns.  They are not used to
-match input records.  Rather, they are used for supplying start-up or
-clean-up information to your @code{awk} script.  A @code{BEGIN} rule is
-executed, once, before the first input record has been read.  An @code{END}
-rule is executed, once, after all the input has been read.  For
-example:@refill
-
-@example
-awk 'BEGIN @{ print "Analysis of `foo'" @}
-     /foo/ @{ ++foobar @}
-     END   @{ print "`foo' appears " foobar " times." @}' BBS-list
-@end example
-
-This program finds the number of records in the input file @file{BBS-list}
-that contain the string @samp{foo}.  The @code{BEGIN} rule prints a title
-for the report.  There is no need to use the @code{BEGIN} rule to
-initialize the counter @code{foobar} to zero, as @code{awk} does this
-for us automatically (@pxref{Variables}).
-
-The second rule increments the variable @code{foobar} every time a
-record containing the pattern @samp{foo} is read.  The @code{END} rule
-prints the value of @code{foobar} at the end of the run.@refill
-
-The special patterns @code{BEGIN} and @code{END} cannot be used in ranges
-or with boolean operators (indeed, they cannot be used with any operators).
-
-An @code{awk} program may have multiple @code{BEGIN} and/or @code{END}
-rules.  They are executed in the order they appear, all the @code{BEGIN}
-rules at start-up and all the @code{END} rules at termination.
-
-Multiple @code{BEGIN} and @code{END} sections are useful for writing
-library functions, since each library can have its own @code{BEGIN} or
-@code{END} rule to do its own initialization and/or cleanup.  Note that
-the order in which library functions are named on the command line
-controls the order in which their @code{BEGIN} and @code{END} rules are
-executed.  Therefore you have to be careful to write such rules in
-library files so that the order in which they are executed doesn't matter.
-@xref{Command Line, ,Invoking @code{awk}}, for more information on
-using library functions.
-
-If an @code{awk} program only has a @code{BEGIN} rule, and no other
-rules, then the program exits after the @code{BEGIN} rule has been run.
-(Older versions of @code{awk} used to keep reading and ignoring input
-until end of file was seen.)  However, if an @code{END} rule exists as
-well, then the input will be read, even if there are no other rules in
-the program.  This is necessary in case the @code{END} rule checks the
-@code{NR} variable.
-
-@code{BEGIN} and @code{END} rules must have actions; there is no default
-action for these rules since there is no current record when they run.
-
-@node Empty,  , BEGIN/END, Patterns
-@comment  node-name,  next,  previous,  up
-@section The Empty Pattern
-
-@cindex empty pattern
-@cindex pattern, empty
-An empty pattern is considered to match @emph{every} input record.  For
-example, the program:@refill
-
-@example
-awk '@{ print $1 @}' BBS-list
-@end example
-
-@noindent
-prints the first field of every record.
-
-@node Actions, Expressions, Patterns, Top
-@chapter Overview of Actions
-@cindex action, definition of
-@cindex curly braces
-@cindex action, curly braces
-@cindex action, separating statements
-
-An @code{awk} program or script consists of a series of
-rules and function definitions, interspersed.  (Functions are
-described later.  @xref{User-defined, ,User-defined Functions}.)
-
-A rule contains a pattern and an action, either of which may be
-omitted.  The purpose of the @dfn{action} is to tell @code{awk} what to do
-once a match for the pattern is found.  Thus, the entire program
-looks somewhat like this:
-
-@example
-@r{[}@var{pattern}@r{]} @r{[}@{ @var{action} @}@r{]}
-@r{[}@var{pattern}@r{]} @r{[}@{ @var{action} @}@r{]}
-@dots{}
-function @var{name} (@var{args}) @{ @dots{} @}
-@dots{}
-@end example
-
-An action consists of one or more @code{awk} @dfn{statements}, enclosed
-in curly braces (@samp{@{} and @samp{@}}).  Each statement specifies one
-thing to be done.  The statements are separated by newlines or
-semicolons.
-
-The curly braces around an action must be used even if the action
-contains only one statement, or even if it contains no statements at
-all.  However, if you omit the action entirely, omit the curly braces as
-well.  (An omitted action is equivalent to @samp{@{ print $0 @}}.)
-
-Here are the kinds of statements supported in @code{awk}:
-
-@itemize @bullet
-@item
-Expressions, which can call functions or assign values to variables
-(@pxref{Expressions, ,Expressions as Action Statements}).  Executing
-this kind of statement simply computes the value of the expression and
-then ignores it.  This is useful when the expression has side effects
-(@pxref{Assignment Ops, ,Assignment Expressions}).@refill
-
-@item
-Control statements, which specify the control flow of @code{awk}
-programs.  The @code{awk} language gives you C-like constructs
-(@code{if}, @code{for}, @code{while}, and so on) as well as a few
-special ones (@pxref{Statements, ,Control Statements in Actions}).@refill
-
-@item
-Compound statements, which consist of one or more statements enclosed in
-curly braces.  A compound statement is used in order to put several
-statements together in the body of an @code{if}, @code{while}, @code{do}
-or @code{for} statement.
-
-@item
-Input control, using the @code{getline} command
-(@pxref{Getline, ,Explicit Input with @code{getline}}), and the @code{next}
-statement (@pxref{Next Statement, ,The @code{next} Statement}).
-
-@item
-Output statements, @code{print} and @code{printf}.
-@xref{Printing, ,Printing Output}.@refill
-
-@item
-Deletion statements, for deleting array elements.
-@xref{Delete, ,The @code{delete} Statement}.@refill
-@end itemize
-
-@iftex
-The next two chapters cover in detail expressions and control
-statements, respectively.  We go on to treat arrays and built-in
-functions, both of which are used in expressions.  Then we proceed
-to discuss how to define your own functions.
-@end iftex
-
-@node Expressions, Statements, Actions, Top
-@chapter Expressions as Action Statements
-@cindex expression
-
-Expressions are the basic building block of @code{awk} actions.  An
-expression evaluates to a value, which you can print, test, store in a
-variable or pass to a function.  But beyond that, an expression can assign a new value to a variable
-or a field, with an assignment operator.
-
-An expression can serve as a statement on its own.  Most other kinds of
-statements contain one or more expressions which specify data to be
-operated on.  As in other languages, expressions in @code{awk} include
-variables, array references, constants, and function calls, as well as
-combinations of these with various operators.
-
-@menu
-* Constants::                   String, numeric, and regexp constants.
-* Variables::                   Variables give names to values for later use.
-* Arithmetic Ops::              Arithmetic operations (@samp{+}, @samp{-}, etc.)
-* Concatenation::               Concatenating strings.
-* Comparison Ops::              Comparison of numbers and strings 
-                                with @samp{<}, etc.
-* Boolean Ops::                 Combining comparison expressions 
-                                using boolean operators
-                                @samp{||} (``or''), @samp{&&} (``and'') and @samp{!} (``not'').
-
-* Assignment Ops::              Changing the value of a variable or a field.
-* Increment Ops::               Incrementing the numeric value of a variable.
-
-* Conversion::                  The conversion of strings to numbers 
-                                and vice versa.
-* Values::                      The whole truth about numbers and strings.
-* Conditional Exp::             Conditional expressions select 
-                                between two subexpressions under control 
-                                of a third subexpression.
-* Function Calls::              A function call is an expression.
-* Precedence::                  How various operators nest.
-@end menu
-
-@node Constants, Variables, Expressions, Expressions
-@section Constant Expressions
-@cindex constants, types of
-@cindex string constants
-
-The simplest type of expression is the @dfn{constant}, which always has
-the same value.  There are three types of constants: numeric constants,
-string constants, and regular expression constants.
-
-@cindex numeric constant
-@cindex numeric value
-A @dfn{numeric constant} stands for a number.  This number can be an
-integer, a decimal fraction, or a number in scientific (exponential)
-notation.  Note that all numeric values are represented within
-@code{awk} in double-precision floating point.  Here are some examples
-of numeric constants, which all have the same value:
-
-@example
-105
-1.05e+2
-1050e-1
-@end example
-
-A string constant consists of a sequence of characters enclosed in
-double-quote marks.  For example:
-
-@example
-"parrot"
-@end example
-
-@noindent
-@iftex
-@cindex differences between @code{gawk} and @code{awk}
-@end iftex
-represents the string whose contents are @samp{parrot}.  Strings in
-@code{gawk} can be of any length and they can contain all the possible
-8-bit ASCII characters including ASCII NUL.  Other @code{awk}
-implementations may have difficulty with some character codes.@refill
-
-@cindex escape sequence notation
-Some characters cannot be included literally in a string constant.  You
-represent them instead with @dfn{escape sequences}, which are character
-sequences beginning with a backslash (@samp{\}).
-
-One use of an escape sequence is to include a double-quote character in
-a string constant.  Since a plain double-quote would end the string, you
-must use @samp{\"} to represent a single double-quote character as a
-part of the string.  
-The 
-backslash character itself is another character that cannot be
-included normally; you write @samp{\\} to put one backslash in the
-string.  Thus, the string whose contents are the two characters
-@samp{"\} must be written @code{"\"\\"}.
-
-Another use of backslash is to represent unprintable characters
-such as newline.  While there is nothing to stop you from writing most
-of these characters directly in a string constant, they may look ugly.
-
-Here is a table of all the escape sequences used in @code{awk}:
-
-@table @code
-@item \\
-Represents a literal backslash, @samp{\}.
-
-@item \a
-Represents the ``alert'' character, control-g, ASCII code 7.
-
-@item \b
-Represents a backspace, control-h, ASCII code 8.
-
-@item \f
-Represents a formfeed, control-l, ASCII code 12.
-
-@item \n
-Represents a newline, control-j, ASCII code 10.
-
-@item \r
-Represents a carriage return, control-m, ASCII code 13.
-
-@item \t
-Represents a horizontal tab, control-i, ASCII code 9.
-
-@item \v
-Represents a vertical tab, control-k, ASCII code 11.
-
-@item \@var{nnn}
-Represents the octal value @var{nnn}, where @var{nnn} are one to three
-digits between 0 and 7.  For example, the code for the ASCII ESC
-(escape) character is @samp{\033}.@refill
-
-@item \x@var{hh}@dots{}
-Represents the hexadecimal value @var{hh}, where @var{hh} are hexadecimal
-digits (@samp{0} through @samp{9} and either @samp{A} through @samp{F} or
-@samp{a} through @samp{f}).  Like the same construct in @sc{ansi} C, the escape
-sequence continues until the first non-hexadecimal digit is seen.  However,
-using more than two hexadecimal digits produces undefined results.  (The
-@samp{\x} escape sequence is not allowed in @sc{posix} @code{awk}.)@refill
-@end table
-
-A @dfn{constant regexp} is a regular expression description enclosed in
-slashes, such as @code{/^beginning and end$/}.  Most regexps used in
-@code{awk} programs are constant, but the @samp{~} and @samp{!~}
-operators can also match computed or ``dynamic'' regexps
-(@pxref{Regexp Usage, ,How to Use Regular Expressions}).@refill
-
-Constant regexps may be used like simple expressions.  When a
-constant regexp is not on the right hand side of the @samp{~} or
-@samp{!~} operators, it has the same meaning as if it appeared
-in a pattern, i.e. @samp{($0 ~ /foo/)}
-(@pxref{Expression Patterns, ,Expressions as Patterns}).
-This means that the two code segments,@refill
-
-@example
-if ($0 ~ /barfly/ || $0 ~ /camelot/)
-    print "found"
-@end example
-
-@noindent
-and
-
-@example
-if (/barfly/ || /camelot/)
-    print "found"
-@end example
-
-@noindent
-are exactly equivalent.  One rather bizarre consequence of this rule is
-that the following boolean expression is legal, but does not do what the user
-intended:@refill
-
-@example
-if (/foo/ ~ $1) print "found foo"
-@end example
-
-This code is ``obviously'' testing @code{$1} for a match against the regexp
-@code{/foo/}.  But in fact, the expression @code{(/foo/ ~ $1)} actually means
-@code{(($0 ~ /foo/) ~ $1)}.  In other words, first match the input record
-against the regexp @code{/foo/}.  The result will be either a 0 or a 1,
-depending upon the success or failure of the match.  Then match that result
-against the first field in the record.@refill
-
-Since it is unlikely that you would ever really wish to make this kind of
-test, @code{gawk} will issue a warning when it sees this construct in
-a program.@refill
-
-Another consequence of this rule is that the assignment statement
-
-@example
-matches = /foo/
-@end example
-
-@noindent
-will assign either 0 or 1 to the variable @code{matches}, depending
-upon the contents of the current input record.
-
-Constant regular expressions are also used as the first argument for
-the @code{sub} and @code{gsub} functions
-(@pxref{String Functions, ,Built-in Functions for String Manipulation}).@refill
-
-This feature of the language was never well documented until the
-@sc{posix} specification.
-
-You may be wondering, when is
-
-@example
-$1 ~ /foo/ @{ @dots{} @}
-@end example
-
-@noindent
-preferable to
-
-@example
-$1 ~ "foo" @{ @dots{} @}
-@end example
-
-Since the right-hand sides of both @samp{~} operators are constants,
-it is more efficient to use the @samp{/foo/} form: @code{awk} can note
-that you have supplied a regexp and store it internally in a form that
-makes pattern matching more efficient.  In the second form, @code{awk}
-must first convert the string into this internal form, and then perform
-the pattern matching.  The first form is also better style; it shows 
-clearly that you intend a regexp match.
-
-@node Variables, Arithmetic Ops, Constants, Expressions
-@section Variables
-@cindex variables, user-defined
-@cindex user-defined variables
-@c there should be more than one subsection, ideally.  Not a big deal.
-@c But usually there are supposed to be at least two.  One way to get
-@c around this is to write the info in the subsection as the info in the
-@c section itself and not have any subsections..  --mew
-
-Variables let you give names to values and refer to them later.  You have
-already seen variables in many of the examples.  The name of a variable
-must be a sequence of letters, digits and underscores, but it may not begin
-with a digit.  Case is significant in variable names; @code{a} and @code{A}
-are distinct variables.
-
-A variable name is a valid expression by itself; it represents the
-variable's current value.  Variables are given new values with
-@dfn{assignment operators} and @dfn{increment operators}.
-@xref{Assignment Ops, ,Assignment Expressions}.
-
-A few variables have special built-in meanings, such as @code{FS}, the
-field separator, and @code{NF}, the number of fields in the current
-input record.  @xref{Built-in Variables}, for a list of them.  These
-built-in variables can be used and assigned just like all other
-variables, but their values are also used or changed automatically by
-@code{awk}.  Each built-in variable's name is made entirely of upper case
-letters.
-
-Variables in @code{awk} can be assigned either numeric or string
-values.  By default, variables are initialized to the null string, which
-is effectively zero if converted to a number.  There is no need to
-``initialize'' each variable explicitly in @code{awk}, the way you would in C or most other traditional languages.
-
-@menu
-* Assignment Options::          Setting variables on the command line
-                                and a summary of command line syntax.
-                                This is an advanced method of input.
-@end menu
-
-@node Assignment Options,  , Variables, Variables
-@subsection Assigning Variables on the Command Line
-
-You can set any @code{awk} variable by including a @dfn{variable assignment}
-among the arguments on the command line when you invoke @code{awk}
-(@pxref{Command Line, ,Invoking @code{awk}}).  Such an assignment has
-this form:@refill
-
-@example
-@var{variable}=@var{text}
-@end example
-
-@noindent
-With it, you can set a variable either at the beginning of the
-@code{awk} run or in between input files.
-
-If you precede the assignment with the @samp{-v} option, like this:
-
-@example
--v @var{variable}=@var{text}
-@end example
-
-@noindent
-then the variable is set at the very beginning, before even the
-@code{BEGIN} rules are run.  The @samp{-v} option and its assignment
-must precede all the file name arguments, as well as the program text.
-
-Otherwise, the variable assignment is performed at a time determined by
-its position among the input file arguments: after the processing of the
-preceding input file argument.  For example:
-
-@example
-awk '@{ print $n @}' n=4 inventory-shipped n=2 BBS-list
-@end example
-
-@noindent
-prints the value of field number @code{n} for all input records.  Before
-the first file is read, the command line sets the variable @code{n}
-equal to 4.  This causes the fourth field to be printed in lines from
-the file @file{inventory-shipped}.  After the first file has finished,
-but before the second file is started, @code{n} is set to 2, so that the
-second field is printed in lines from @file{BBS-list}.
-
-Command line arguments are made available for explicit examination by
-the @code{awk} program in an array named @code{ARGV}
-(@pxref{Built-in Variables}).@refill
-
-@code{awk} processes the values of command line assignments for escape
-sequences (@pxref{Constants, ,Constant Expressions}).
-
-@node Arithmetic Ops, Concatenation, Variables, Expressions
-@section Arithmetic Operators
-@cindex arithmetic operators
-@cindex operators, arithmetic
-@cindex addition
-@cindex subtraction
-@cindex multiplication
-@cindex division
-@cindex remainder
-@cindex quotient
-@cindex exponentiation
-
-The @code{awk} language uses the common arithmetic operators when
-evaluating expressions.  All of these arithmetic operators follow normal
-precedence rules, and work as you would expect them to.  This example
-divides field three by field four, adds field two, stores the result
-into field one, and prints the resulting altered input record:
-
-@example
-awk '@{ $1 = $2 + $3 / $4; print @}' inventory-shipped
-@end example
-
-The arithmetic operators in @code{awk} are:
-
-@table @code
-@item @var{x} + @var{y}
-Addition.
-
-@item @var{x} - @var{y}
-Subtraction.
-
-@item - @var{x}
-Negation.
-
-@item + @var{x}
-Unary plus.  No real effect on the expression.
-
-@item @var{x} * @var{y}
-Multiplication.
-
-@item @var{x} / @var{y}
-Division.  Since all numbers in @code{awk} are double-precision
-floating point, the result is not rounded to an integer: @code{3 / 4}
-has the value 0.75.
-
-@item @var{x} % @var{y}
-@iftex
-@cindex differences between @code{gawk} and @code{awk}
-@end iftex
-Remainder.  The quotient is rounded toward zero to an integer,
-multiplied by @var{y} and this result is subtracted from @var{x}.
-This operation is sometimes known as ``trunc-mod.''  The following
-relation always holds:
-
-@example
-b * int(a / b) + (a % b) == a
-@end example
-
-One possibly undesirable effect of this definition of remainder is that
-@code{@var{x} % @var{y}} is negative if @var{x} is negative.  Thus,
-
-@example
--17 % 8 = -1
-@end example
-
-In other @code{awk} implementations, the signedness of the remainder
-may be machine dependent.
-
-@item @var{x} ^ @var{y}
-@itemx @var{x} ** @var{y}
-Exponentiation: @var{x} raised to the @var{y} power.  @code{2 ^ 3} has
-the value 8.  The character sequence @samp{**} is equivalent to
-@samp{^}.  (The @sc{posix} standard only specifies the use of @samp{^}
-for exponentiation.)
-@end table
-
-@node Concatenation, Comparison Ops, Arithmetic Ops, Expressions
-@section String Concatenation
-
-@cindex string operators
-@cindex operators, string
-@cindex concatenation
-There is only one string operation: concatenation.  It does not have a
-specific operator to represent it.  Instead, concatenation is performed by
-writing expressions next to one another, with no operator.  For example:
-
-@example
-awk '@{ print "Field number one: " $1 @}' BBS-list
-@end example
-
-@noindent
-produces, for the first record in @file{BBS-list}:
-
-@example
-Field number one: aardvark
-@end example
-
-Without the space in the string constant after the @samp{:}, the line
-would run together.  For example:
-
-@example
-awk '@{ print "Field number one:" $1 @}' BBS-list
-@end example
-
-@noindent
-produces, for the first record in @file{BBS-list}:
-
-@example
-Field number one:aardvark
-@end example
-
-Since string concatenation does not have an explicit operator, it is
-often necessary to insure that it happens where you want it to by
-enclosing the items to be concatenated in parentheses.  For example, the
-following code fragment does not concatenate @code{file} and @code{name}
-as you might expect:
-
-@example
-file = "file"
-name = "name"
-print "something meaningful" > file name
-@end example
-
-@noindent
-It is necessary to use the following:
-
-@example
-print "something meaningful" > (file name)
-@end example
-
-We recommend you use parentheses around concatenation in all but the
-most common contexts (such as in the right-hand operand of @samp{=}).
-
-@ignore
-@code{gawk} actually now allows a concatenation on the right hand
-side of a @code{>} redirection, but other @code{awk}s don't.  So for
-now we won't mention that fact.
-@end ignore
-
-@node Comparison Ops, Boolean Ops, Concatenation, Expressions
-@section Comparison Expressions
-@cindex comparison expressions
-@cindex expressions, comparison
-@cindex relational operators
-@cindex operators, relational
-@cindex regexp operators
-
-@dfn{Comparison expressions} compare strings or numbers for
-relationships such as equality.  They are written using @dfn{relational
-operators}, which are a superset of those in C.  Here is a table of
-them:
-
-@table @code
-@item @var{x} < @var{y}
-True if @var{x} is less than @var{y}.
-
-@item @var{x} <= @var{y}
-True if @var{x} is less than or equal to @var{y}.
-
-@item @var{x} > @var{y}
-True if @var{x} is greater than @var{y}.
-
-@item @var{x} >= @var{y}
-True if @var{x} is greater than or equal to @var{y}.
-
-@item @var{x} == @var{y}
-True if @var{x} is equal to @var{y}.
-
-@item @var{x} != @var{y}
-True if @var{x} is not equal to @var{y}.
-
-@item @var{x} ~ @var{y}
-True if the string @var{x} matches the regexp denoted by @var{y}.
-
-@item @var{x} !~ @var{y}
-True if the string @var{x} does not match the regexp denoted by @var{y}.
-
-@item @var{subscript} in @var{array}
-True if array @var{array} has an element with the subscript @var{subscript}.
-@end table
-
-Comparison expressions have the value 1 if true and 0 if false.
-
-The rules @code{gawk} uses for performing comparisons are based on those
-in draft 11.2 of the @sc{posix} standard.  The @sc{posix} standard introduced
-the concept of a @dfn{numeric string}, which is simply a string that looks
-like a number, for example, @code{@w{" +2"}}.
-
-@vindex CONVFMT
-When performing a relational operation, @code{gawk} considers the type of an
-operand to be the type it received on its last @emph{assignment}, rather
-than the type of its last @emph{use}
-(@pxref{Values, ,Numeric and String Values}).
-This type is @emph{unknown} when the operand is from an ``external'' source:
-field variables, command line arguments, array elements resulting from a
-@code{split} operation, and the value of an @code{ENVIRON} element.
-In this case only, if the operand is a numeric string, then it is
-considered to be of both string type and numeric type.  If at least one
-operand of a comparison is of string type only, then a string
-comparison is performed.  Any numeric operand will be converted to a
-string using the value of @code{CONVFMT}
-(@pxref{Conversion, ,Conversion of Strings and Numbers}).
-If one operand of a comparison is numeric, and the other operand is
-either numeric or both numeric and string, then @code{gawk} does a
-numeric comparison.  If both operands have both types, then the
-comparison is numeric.  Strings are compared
-by comparing the first character of each, then the second character of each,
-and so on.  Thus @code{"10"} is less than @code{"9"}.  If there are two
-strings where one is a prefix of the other, the shorter string is less than
-the longer one.  Thus @code{"abc"} is less than @code{"abcd"}.@refill
-
-Here are some sample expressions, how @code{gawk} compares them, and what
-the result of the comparison is.
-
-@table @code
-@item 1.5 <= 2.0
-numeric comparison (true)
-
-@item "abc" >= "xyz"
-string comparison (false)
-
-@item 1.5 != " +2"
-string comparison (true)
-
-@item "1e2" < "3"
-string comparison (true)
-
-@item a = 2; b = "2"
-@itemx a == b
-string comparison (true)
-@end table
-
-@example
-echo 1e2 3 | awk '@{ print ($1 < $2) ? "true" : "false" @}'
-@end example
-
-@noindent
-prints @samp{false} since both @code{$1} and @code{$2} are numeric
-strings and thus have both string and numeric types, thus dictating
-a numeric comparison.
-
-The purpose of the comparison rules and the use of numeric strings is
-to attempt to produce the behavior that is ``least surprising,'' while
-still ``doing the right thing.''
-
-String comparisons and regular expression comparisons are very different.
-For example,
-
-@example
-$1 == "foo"
-@end example
-
-@noindent
-has the value of 1, or is true, if the first field of the current input
-record is precisely @samp{foo}.  By contrast, 
-
-@example
-$1 ~ /foo/
-@end example
-
-@noindent
-has the value 1 if the first field contains @samp{foo}, such as @samp{foobar}.
-
-The right hand operand of the @samp{~} and @samp{!~} operators may be
-either a constant regexp (@code{/@dots{}/}), or it may be an ordinary
-expression, in which case the value of the expression as a string is a
-dynamic regexp (@pxref{Regexp Usage, ,How to Use Regular Expressions}).
-
-@cindex regexp as expression
-In very recent implementations of @code{awk}, a constant regular
-expression in slashes by itself is also an expression.  The regexp
-@code{/@var{regexp}/} is an abbreviation for this comparison expression:
-
-@example
-$0 ~ /@var{regexp}/
-@end example
-
-In some contexts it may be necessary to write parentheses around the
-regexp to avoid confusing the @code{gawk} parser.  For example,
-@code{(/x/ - /y/) > threshold} is not allowed, but @code{((/x/) - (/y/))
-> threshold} parses properly.
-
-One special place where @code{/foo/} is @emph{not} an abbreviation for
-@code{$0 ~ /foo/} is when it is the right-hand operand of @samp{~} or
-@samp{!~}! @xref{Constants, ,Constant Expressions}, where this is
-discussed in more detail.
-
-@node Boolean Ops, Assignment Ops, Comparison Ops, Expressions
-@section Boolean Expressions
-@cindex expressions, boolean
-@cindex boolean expressions
-@cindex operators, boolean
-@cindex boolean operators
-@cindex logical operations
-@cindex and operator
-@cindex or operator
-@cindex not operator
-
-A @dfn{boolean expression} is a combination of comparison expressions or
-matching expressions, using the boolean operators ``or''
-(@samp{||}), ``and'' (@samp{&&}), and ``not'' (@samp{!}), along with
-parentheses to control nesting.  The truth of the boolean expression is
-computed by combining the truth values of the component expressions.
-
-Boolean expressions can be used wherever comparison and matching
-expressions can be used.  They can be used in @code{if}, @code{while}
-@code{do} and @code{for} statements.  They have numeric values (1 if true,
-0 if false), which come into play if the result of the boolean expression
-is stored in a variable, or used in arithmetic.@refill
-
-In addition, every boolean expression is also a valid boolean pattern, so
-you can use it as a pattern to control the execution of rules.
-
-Here are descriptions of the three boolean operators, with an example of
-each.  It may be instructive to compare these examples with the
-analogous examples of boolean patterns
-(@pxref{Boolean Patterns, ,Boolean Operators and Patterns}), which
-use the same boolean operators in patterns instead of expressions.@refill
-
-@table @code
-@item @var{boolean1} && @var{boolean2}
-True if both @var{boolean1} and @var{boolean2} are true.  For example,
-the following statement prints the current input record if it contains
-both @samp{2400} and @samp{foo}.@refill
-
-@smallexample
-if ($0 ~ /2400/ && $0 ~ /foo/) print
-@end smallexample
-
-The subexpression @var{boolean2} is evaluated only if @var{boolean1}
-is true.  This can make a difference when @var{boolean2} contains
-expressions that have side effects: in the case of @code{$0 ~ /foo/ &&
-($2 == bar++)}, the variable @code{bar} is not incremented if there is
-no @samp{foo} in the record.
-
-@item @var{boolean1} || @var{boolean2}
-True if at least one of @var{boolean1} or @var{boolean2} is true.
-For example, the following command prints all records in the input
-file @file{BBS-list} that contain @emph{either} @samp{2400} or
-@samp{foo}, or both.@refill
-
-@smallexample
-awk '@{ if ($0 ~ /2400/ || $0 ~ /foo/) print @}' BBS-list
-@end smallexample
-
-The subexpression @var{boolean2} is evaluated only if @var{boolean1}
-is false.  This can make a difference when @var{boolean2} contains
-expressions that have side effects.
-
-@item !@var{boolean}
-True if @var{boolean} is false.  For example, the following program prints
-all records in the input file @file{BBS-list} that do @emph{not} contain the
-string @samp{foo}.
-
-@smallexample
-awk '@{ if (! ($0 ~ /foo/)) print @}' BBS-list
-@end smallexample
-@end table
-
-@node Assignment Ops, Increment Ops, Boolean Ops, Expressions
-@section Assignment Expressions
-@cindex assignment operators
-@cindex operators, assignment
-@cindex expressions, assignment
-
-An @dfn{assignment} is an expression that stores a new value into a
-variable.  For example, let's assign the value 1 to the variable
-@code{z}:@refill
-
-@example
-z = 1
-@end example
-
-After this expression is executed, the variable @code{z} has the value 1.
-Whatever old value @code{z} had before the assignment is forgotten.
-
-Assignments can store string values also.  For example, this would store
-the value @code{"this food is good"} in the variable @code{message}:
-
-@example
-thing = "food"
-predicate = "good"
-message = "this " thing " is " predicate
-@end example
-
-@noindent
-(This also illustrates concatenation of strings.)
-
-The @samp{=} sign is called an @dfn{assignment operator}.  It is the
-simplest assignment operator because the value of the right-hand
-operand is stored unchanged.
-
-@cindex side effect
-Most operators (addition, concatenation, and so on) have no effect
-except to compute a value.  If you ignore the value, you might as well
-not use the operator.  An assignment operator is different; it does
-produce a value, but even if you ignore the value, the assignment still
-makes itself felt through the alteration of the variable.  We call this
-a @dfn{side effect}.
-
-@cindex lvalue
-The left-hand operand of an assignment need not be a variable
-(@pxref{Variables}); it can also be a field
-(@pxref{Changing Fields, ,Changing the Contents of a Field}) or
-an array element (@pxref{Arrays, ,Arrays in @code{awk}}).
-These are all called @dfn{lvalues},
-which means they can appear on the left-hand side of an assignment operator.
-The right-hand operand may be any expression; it produces the new value
-which the assignment stores in the specified variable, field or array
-element.@refill
-
-It is important to note that variables do @emph{not} have permanent types.
-The type of a variable is simply the type of whatever value it happens
-to hold at the moment.  In the following program fragment, the variable
-@code{foo} has a numeric value at first, and a string value later on:
-
-@example
-foo = 1
-print foo
-foo = "bar"
-print foo
-@end example
-
-@noindent
-When the second assignment gives @code{foo} a string value, the fact that
-it previously had a numeric value is forgotten.
-
-An assignment is an expression, so it has a value: the same value that
-is assigned.  Thus, @code{z = 1} as an expression has the value 1.
-One consequence of this is that you can write multiple assignments together:
-
-@example
-x = y = z = 0
-@end example
-
-@noindent
-stores the value 0 in all three variables.  It does this because the
-value of @code{z = 0}, which is 0, is stored into @code{y}, and then
-the value of @code{y = z = 0}, which is 0, is stored into @code{x}.
-
-You can use an assignment anywhere an expression is called for.  For
-example, it is valid to write @code{x != (y = 1)} to set @code{y} to 1
-and then test whether @code{x} equals 1.  But this style tends to make
-programs hard to read; except in a one-shot program, you should
-rewrite it to get rid of such nesting of assignments.  This is never very
-hard.
-
-Aside from @samp{=}, there are several other assignment operators that
-do arithmetic with the old value of the variable.  For example, the
-operator @samp{+=} computes a new value by adding the right-hand value
-to the old value of the variable.  Thus, the following assignment adds
-5 to the value of @code{foo}:
-
-@example
-foo += 5
-@end example
-
-@noindent
-This is precisely equivalent to the following:
-
-@example
-foo = foo + 5
-@end example
-
-@noindent
-Use whichever one makes the meaning of your program clearer.
-
-Here is a table of the arithmetic assignment operators.  In each
-case, the right-hand operand is an expression whose value is converted
-to a number.
-
-@table @code
-@item @var{lvalue} += @var{increment}
-Adds @var{increment} to the value of @var{lvalue} to make the new value
-of @var{lvalue}.
-
-@item @var{lvalue} -= @var{decrement}
-Subtracts @var{decrement} from the value of @var{lvalue}.
-
-@item @var{lvalue} *= @var{coefficient}
-Multiplies the value of @var{lvalue} by @var{coefficient}.
-
-@item @var{lvalue} /= @var{quotient}
-Divides the value of @var{lvalue} by @var{quotient}.
-
-@item @var{lvalue} %= @var{modulus}
-Sets @var{lvalue} to its remainder by @var{modulus}.
-
-@item @var{lvalue} ^= @var{power}
-@itemx @var{lvalue} **= @var{power}
-Raises @var{lvalue} to the power @var{power}.
-(Only the @code{^=} operator is specified by @sc{posix}.)
-@end table
-
-@ignore
-From: gatech!ames!elroy!cit-vax!EQL.Caltech.Edu!rankin (Pat Rankin)
-     In the discussion of assignment operators, it states that
-``foo += 5'' "is precisely equivalent to" ``foo = foo + 5'' (p.77).  That
-may be true for simple variables, but it's not true for expressions with
-side effects, like array references.  For proof, try
-  BEGIN {
-	  foo[rand()] += 5;               for (x in foo) print x, foo[x]
-	  bar[rand()] = bar[rand()] + 5;  for (x in bar) print x, bar[x]
-  }
-I suspect that the original statement is simply untrue--that '+=' is more
-efficient in all cases.
-
-ADR --- Try to add something about this here for the next go 'round.
-@end ignore
-
-@node Increment Ops, Conversion, Assignment Ops, Expressions
-@section Increment Operators
-
-@cindex increment operators
-@cindex operators, increment
-@dfn{Increment operators} increase or decrease the value of a variable
-by 1.  You could do the same thing with an assignment operator, so
-the increment operators add no power to the @code{awk} language; but they
-are convenient abbreviations for something very common.
-
-The operator to add 1 is written @samp{++}.  It can be used to increment
-a variable either before or after taking its value.
-
-To pre-increment a variable @var{v}, write @code{++@var{v}}.  This adds
-1 to the value of @var{v} and that new value is also the value of this
-expression.  The assignment expression @code{@var{v} += 1} is completely
-equivalent.
-
-Writing the @samp{++} after the variable specifies post-increment.  This
-increments the variable value just the same; the difference is that the
-value of the increment expression itself is the variable's @emph{old}
-value.  Thus, if @code{foo} has the value 4, then the expression @code{foo++}
-has the value 4, but it changes the value of @code{foo} to 5.
-
-The post-increment @code{foo++} is nearly equivalent to writing @code{(foo
-+= 1) - 1}.  It is not perfectly equivalent because all numbers in
-@code{awk} are floating point: in floating point, @code{foo + 1 - 1} does
-not necessarily equal @code{foo}.  But the difference is minute as
-long as you stick to numbers that are fairly small (less than a trillion).
-
-Any lvalue can be incremented.  Fields and array elements are incremented
-just like variables.  (Use @samp{$(i++)} when you wish to do a field reference
-and a variable increment at the same time.  The parentheses are necessary
-because of the precedence of the field reference operator, @samp{$}.)
-@c expert information in the last parenthetical remark
-
-The decrement operator @samp{--} works just like @samp{++} except that
-it subtracts 1 instead of adding.  Like @samp{++}, it can be used before
-the lvalue to pre-decrement or after it to post-decrement.
-
-Here is a summary of increment and decrement expressions.
-
-@table @code
-@item ++@var{lvalue}
-This expression increments @var{lvalue} and the new value becomes the
-value of this expression.
-
-@item @var{lvalue}++
-This expression causes the contents of @var{lvalue} to be incremented.
-The value of the expression is the @emph{old} value of @var{lvalue}.
-
-@item --@var{lvalue}
-Like @code{++@var{lvalue}}, but instead of adding, it subtracts.  It
-decrements @var{lvalue} and delivers the value that results.
-
-@item @var{lvalue}--
-Like @code{@var{lvalue}++}, but instead of adding, it subtracts.  It
-decrements @var{lvalue}.  The value of the expression is the @emph{old}
-value of @var{lvalue}.
-@end table
-
-@node Conversion, Values, Increment Ops, Expressions
-@section Conversion of Strings and Numbers
-
-@cindex conversion of strings and numbers
-Strings are converted to numbers, and numbers to strings, if the context
-of the @code{awk} program demands it.  For example, if the value of
-either @code{foo} or @code{bar} in the expression @code{foo + bar}
-happens to be a string, it is converted to a number before the addition
-is performed.  If numeric values appear in string concatenation, they
-are converted to strings.  Consider this:@refill
-
-@example
-two = 2; three = 3
-print (two three) + 4
-@end example
-
-@noindent
-This eventually prints the (numeric) value 27.  The numeric values of
-the variables @code{two} and @code{three} are converted to strings and
-concatenated together, and the resulting string is converted back to the
-number 23, to which 4 is then added.
-
-If, for some reason, you need to force a number to be converted to a
-string, concatenate the null string with that number.  To force a string
-to be converted to a number, add zero to that string.
-
-A string is converted to a number by interpreting a numeric prefix
-of the string as numerals:
-@code{"2.5"} converts to 2.5, @code{"1e3"} converts to 1000, and @code{"25fix"}
-has a numeric value of 25.
-Strings that can't be interpreted as valid numbers are converted to
-zero.
-
-@vindex CONVFMT
-The exact manner in which numbers are converted into strings is controlled
-by the @code{awk} built-in variable @code{CONVFMT} (@pxref{Built-in Variables}).
-Numbers are converted using a special version of the @code{sprintf} function
-(@pxref{Built-in, ,Built-in Functions}) with @code{CONVFMT} as the format
-specifier.@refill
-
-@code{CONVFMT}'s default value is @code{"%.6g"}, which prints a value with
-at least six significant digits.  For some applications you will want to
-change it to specify more precision.  Double precision on most modern
-machines gives you 16 or 17 decimal digits of precision.
-
-Strange results can happen if you set @code{CONVFMT} to a string that doesn't
-tell @code{sprintf} how to format floating point numbers in a useful way.
-For example, if you forget the @samp{%} in the format, all numbers will be
-converted to the same constant string.@refill
-
-As a special case, if a number is an integer, then the result of converting
-it to a string is @emph{always} an integer, no matter what the value of
-@code{CONVFMT} may be.  Given the following code fragment:
-
-@example
-CONVFMT = "%2.2f"
-a = 12
-b = a ""
-@end example
-
-@noindent
-@code{b} has the value @code{"12"}, not @code{"12.00"}.
-
-@ignore
-For the 2.14 version, describe the ``stickyness'' of conversions.  Right now
-the manual assumes everywhere that variables are either numbers or strings;
-in fact both kinds of values may be valid.  If both happen to be valid, a
-conversion isn't necessary and isn't done.  Revising the manual to be
-consistent with this, though, is too big a job to tackle at the moment.
-
-7/92: This has sort of been done, only the section isn't completely right!
-      What to do?
-7/92: Pretty much fixed, at least for the short term, thanks to text
-      from David.
-@end ignore
-
-@vindex OFMT
-Prior to the @sc{posix} standard, @code{awk} specified that the value
-of @code{OFMT} was used for converting numbers to strings.  @code{OFMT}
-specifies the output format to use when printing numbers with @code{print}.
-@code{CONVFMT} was introduced in order to separate the semantics of
-conversions from the semantics of printing.  Both @code{CONVFMT} and
-@code{OFMT} have the same default value: @code{"%.6g"}.  In the vast majority
-of cases, old @code{awk} programs will not change their behavior.
-However, this use of @code{OFMT} is something to keep in mind if you must
-port your program to other implementations of @code{awk}; we recommend
-that instead of changing your programs, you just port @code{gawk} itself!@refill
-
-@node Values, Conditional Exp, Conversion, Expressions
-@section Numeric and String Values
-@cindex conversion of strings and numbers
-
-Through most of this manual, we present @code{awk} values (such as constants,
-fields, or variables) as @emph{either} numbers @emph{or} strings.  This is
-a convenient way to think about them, since typically they are used in only
-one way, or the other.
-
-In truth though, @code{awk} values can be @emph{both} string and
-numeric, at the same time.  Internally, @code{awk} represents values
-with a string, a (floating point) number, and an indication that one,
-the other, or both representations of the value are valid.
-
-Keeping track of both kinds of values is important for execution
-efficiency:  a variable can acquire a string value the first time it
-is used as a string, and then that string value can be used until the
-variable is assigned a new value.  Thus, if a variable with only a numeric
-value is used in several concatenations in a row, it only has to be given
-a string representation once.  The numeric value remains valid, so that
-no conversion back to a number is necessary if the variable is later used
-in an arithmetic expression.
-
-Tracking both kinds of values is also important for precise numerical
-calculations.  Consider the following:
-
-@smallexample
-a = 123.321
-CONVFMT = "%3.1f"
-b = a " is a number"
-c = a + 1.654
-@end smallexample
-
-@noindent
-The variable @code{a} receives a string value in the concatenation and
-assignment to @code{b}.  The string value of @code{a} is @code{"123.3"}.
-If the numeric value was lost when it was converted to a string, then the
-numeric use of @code{a} in the last statement would lose information.
-@code{c} would be assigned the value 124.954 instead of 124.975.
-Such errors accumulate rapidly, and very adversely affect numeric
-computations.@refill
-
-Once a numeric value acquires a corresponding string value, it stays valid
-until a new assignment is made.  If @code{CONVFMT}
-(@pxref{Conversion, ,Conversion of Strings and Numbers}) changes in the
-meantime, the old string value will still be used.  For example:@refill
-
-@smallexample
-BEGIN @{
-    CONVFMT = "%2.2f"
-    a = 123.456
-    b = a ""                # force `a' to have string value too
-    printf "a = %s\n", a
-    CONVFMT = "%.6g"
-    printf "a = %s\n", a
-    a += 0                  # make `a' numeric only again
-    printf "a = %s\n", a    # use `a' as string
-@}
-@end smallexample
-
-@noindent
-This program prints @samp{a = 123.46} twice, and then prints
-@samp{a = 123.456}.
-
-@xref{Conversion, ,Conversion of Strings and Numbers}, for the rules that
-specify how string values are made from numeric values.
-
-@node Conditional Exp, Function Calls, Values, Expressions
-@section Conditional Expressions
-@cindex conditional expression
-@cindex expression, conditional
-
-A @dfn{conditional expression} is a special kind of expression with
-three operands.  It allows you to use one expression's value to select
-one of two other expressions.
-
-The conditional expression looks the same as in the C language:
-
-@example
-@var{selector} ? @var{if-true-exp} : @var{if-false-exp}
-@end example
-
-@noindent
-There are three subexpressions.  The first, @var{selector}, is always
-computed first.  If it is ``true'' (not zero and not null) then
-@var{if-true-exp} is computed next and its value becomes the value of
-the whole expression.  Otherwise, @var{if-false-exp} is computed next
-and its value becomes the value of the whole expression.@refill
-
-For example, this expression produces the absolute value of @code{x}:
-
-@example
-x > 0 ? x : -x
-@end example
-
-Each time the conditional expression is computed, exactly one of
-@var{if-true-exp} and @var{if-false-exp} is computed; the other is ignored.
-This is important when the expressions contain side effects.  For example,
-this conditional expression examines element @code{i} of either array
-@code{a} or array @code{b}, and increments @code{i}.
-
-@example
-x == y ? a[i++] : b[i++]
-@end example
-
-@noindent
-This is guaranteed to increment @code{i} exactly once, because each time
-one or the other of the two increment expressions is executed,
-and the other is not.
-
-@node Function Calls, Precedence, Conditional Exp, Expressions
-@section Function Calls
-@cindex function call
-@cindex calling a function
-
-A @dfn{function} is a name for a particular calculation.  Because it has
-a name, you can ask for it by name at any point in the program.  For
-example, the function @code{sqrt} computes the square root of a number.
-
-A fixed set of functions are @dfn{built-in}, which means they are
-available in every @code{awk} program.  The @code{sqrt} function is one
-of these.  @xref{Built-in, ,Built-in Functions}, for a list of built-in
-functions and their descriptions.  In addition, you can define your own
-functions in the program for use elsewhere in the same program.
-@xref{User-defined, ,User-defined Functions}, for how to do this.@refill
-
-@cindex arguments in function call
-The way to use a function is with a @dfn{function call} expression,
-which consists of the function name followed by a list of
-@dfn{arguments} in parentheses.  The arguments are expressions which
-give the raw materials for the calculation that the function will do.
-When there is more than one argument, they are separated by commas.  If
-there are no arguments, write just @samp{()} after the function name.
-Here are some examples:
-
-@example
-sqrt(x^2 + y^2)      # @r{One argument}
-atan2(y, x)          # @r{Two arguments}
-rand()               # @r{No arguments}
-@end example
-
-@strong{Do not put any space between the function name and the
-open-parenthesis!}  A user-defined function name looks just like the name of
-a variable, and space would make the expression look like concatenation
-of a variable with an expression inside parentheses.  Space before the
-parenthesis is harmless with built-in functions, but it is best not to get
-into the habit of using space to avoid mistakes with user-defined
-functions. 
-
-Each function expects a particular number of arguments.  For example, the
-@code{sqrt} function must be called with a single argument, the number
-to take the square root of:
-
-@example
-sqrt(@var{argument})
-@end example
-
-Some of the built-in functions allow you to omit the final argument.
-If you do so, they use a reasonable default.
-@xref{Built-in, ,Built-in Functions}, for full details.  If arguments
-are omitted in calls to user-defined functions, then those arguments are
-treated as local variables, initialized to the null string
-(@pxref{User-defined, ,User-defined Functions}).@refill
-
-Like every other expression, the function call has a value, which is
-computed by the function based on the arguments you give it.  In this
-example, the value of @code{sqrt(@var{argument})} is the square root of the
-argument.  A function can also have side effects, such as assigning the
-values of certain variables or doing I/O.
-
-Here is a command to read numbers, one number per line, and print the
-square root of each one:
-
-@example
-awk '@{ print "The square root of", $1, "is", sqrt($1) @}'
-@end example
-
-@node Precedence,  , Function Calls, Expressions
-@section Operator Precedence (How Operators Nest)
-@cindex precedence
-@cindex operator precedence
-
-@dfn{Operator precedence} determines how operators are grouped, when
-different operators appear close by in one expression.  For example,
-@samp{*} has higher precedence than @samp{+}; thus, @code{a + b * c}
-means to multiply @code{b} and @code{c}, and then add @code{a} to the
-product (i.e., @code{a + (b * c)}).
-
-You can overrule the precedence of the operators by using parentheses.
-You can think of the precedence rules as saying where the
-parentheses are assumed if you do not write parentheses yourself.  In
-fact, it is wise to always use parentheses whenever you have an unusual
-combination of operators, because other people who read the program may
-not remember what the precedence is in this case.  You might forget,
-too; then you could make a mistake.  Explicit parentheses will help prevent
-any such mistake.
-
-When operators of equal precedence are used together, the leftmost
-operator groups first, except for the assignment, conditional and
-exponentiation operators, which group in the opposite order.
-Thus, @code{a - b + c} groups as @code{(a - b) + c};
-@code{a = b = c} groups as @code{a = (b = c)}.@refill
-
-The precedence of prefix unary operators does not matter as long as only
-unary operators are involved, because there is only one way to parse
-them---innermost first.  Thus, @code{$++i} means @code{$(++i)} and
-@code{++$x} means @code{++($x)}.  However, when another operator follows
-the operand, then the precedence of the unary operators can matter.
-Thus, @code{$x^2} means @code{($x)^2}, but @code{-x^2} means
-@code{-(x^2)}, because @samp{-} has lower precedence than @samp{^}
-while @samp{$} has higher precedence.
-
-Here is a table of the operators of @code{awk}, in order of increasing
-precedence:
-
-@table @asis
-@item assignment
-@samp{=}, @samp{+=}, @samp{-=}, @samp{*=}, @samp{/=}, @samp{%=},
-@samp{^=}, @samp{**=}.  These operators group right-to-left.
-(The @samp{**=} operator is not specified by @sc{posix}.)
-
-@item conditional
-@samp{?:}.  This operator groups right-to-left.
-
-@item logical ``or''.
-@samp{||}.
-
-@item logical ``and''.
-@samp{&&}.
-
-@item array membership
-@samp{in}.
-
-@item matching
-@samp{~}, @samp{!~}.
-
-@item relational, and redirection
-The relational operators and the redirections have the same precedence
-level.  Characters such as @samp{>} serve both as relationals and as
-redirections; the context distinguishes between the two meanings.
-
-The relational operators are @samp{<}, @samp{<=}, @samp{==}, @samp{!=},
-@samp{>=} and @samp{>}.
-
-The I/O redirection operators are @samp{<}, @samp{>}, @samp{>>} and
-@samp{|}.
-
-Note that I/O redirection operators in @code{print} and @code{printf}
-statements belong to the statement level, not to expressions.  The
-redirection does not produce an expression which could be the operand of
-another operator.  As a result, it does not make sense to use a
-redirection operator near another operator of lower precedence, without
-parentheses.  Such combinations, for example @samp{print foo > a ? b :
-c}, result in syntax errors.
-
-@item concatenation
-No special token is used to indicate concatenation.
-The operands are simply written side by side.
-
-@item add, subtract
-@samp{+}, @samp{-}.
-
-@item multiply, divide, mod
-@samp{*}, @samp{/}, @samp{%}.
-
-@item unary plus, minus, ``not''
-@samp{+}, @samp{-}, @samp{!}.
-
-@item exponentiation
-@samp{^}, @samp{**}.  These operators group right-to-left.
-(The @samp{**} operator is not specified by @sc{posix}.)
-
-@item increment, decrement
-@samp{++}, @samp{--}.
-
-@item field
-@samp{$}.
-@end table
-
-@node Statements, Arrays, Expressions, Top
-@chapter Control Statements in Actions
-@cindex control statement
-
-@dfn{Control statements} such as @code{if}, @code{while}, and so on
-control the flow of execution in @code{awk} programs.  Most of the
-control statements in @code{awk} are patterned on similar statements in
-C.
-
-All the control statements start with special keywords such as @code{if}
-and @code{while}, to distinguish them from simple expressions.
-
-Many control statements contain other statements; for example, the
-@code{if} statement contains another statement which may or may not be
-executed.  The contained statement is called the @dfn{body}.  If you
-want to include more than one statement in the body, group them into a
-single compound statement with curly braces, separating them with
-newlines or semicolons.
-
-@menu
-* If Statement::                Conditionally execute 
-                                some @code{awk} statements.
-* While Statement::             Loop until some condition is satisfied.
-* Do Statement::                Do specified action while looping until some
-                                condition is satisfied.
-* For Statement::               Another looping statement, that provides
-                                initialization and increment clauses.
-* Break Statement::             Immediately exit the innermost enclosing loop.
-* Continue Statement::          Skip to the end of the innermost 
-                                enclosing loop.
-* Next Statement::              Stop processing the current input record.
-* Next File Statement::         Stop processing the current file.
-* Exit Statement::              Stop execution of @code{awk}.
-@end menu
-
-@node If Statement, While Statement, Statements, Statements
-@section The @code{if} Statement
-
-@cindex @code{if} statement
-The @code{if}-@code{else} statement is @code{awk}'s decision-making
-statement.  It looks like this:@refill
-
-@example
-if (@var{condition}) @var{then-body} @r{[}else @var{else-body}@r{]}
-@end example
-
-@noindent
-@var{condition} is an expression that controls what the rest of the
-statement will do.  If @var{condition} is true, @var{then-body} is
-executed; otherwise, @var{else-body} is executed (assuming that the
-@code{else} clause is present).  The @code{else} part of the statement is
-optional.  The condition is considered false if its value is zero or
-the null string, and true otherwise.@refill
-
-Here is an example:
-
-@example
-if (x % 2 == 0)
-    print "x is even"
-else
-    print "x is odd"
-@end example
-
-In this example, if the expression @code{x % 2 == 0} is true (that is,
-the value of @code{x} is divisible by 2), then the first @code{print}
-statement is executed, otherwise the second @code{print} statement is
-performed.@refill
-
-If the @code{else} appears on the same line as @var{then-body}, and
-@var{then-body} is not a compound statement (i.e., not surrounded by
-curly braces), then a semicolon must separate @var{then-body} from
-@code{else}.  To illustrate this, let's rewrite the previous example:
-
-@example
-awk '@{ if (x % 2 == 0) print "x is even"; else
-        print "x is odd" @}'
-@end example
-
-@noindent
-If you forget the @samp{;}, @code{awk} won't be able to parse the
-statement, and you will get a syntax error.
-
-We would not actually write this example this way, because a human
-reader might fail to see the @code{else} if it were not the first thing
-on its line.
-
-@node While Statement, Do Statement, If Statement, Statements
-@section The @code{while} Statement
-@cindex @code{while} statement
-@cindex loop
-@cindex body of a loop
-
-In programming, a @dfn{loop} means a part of a program that is (or at least can
-be) executed two or more times in succession.
-
-The @code{while} statement is the simplest looping statement in
-@code{awk}.  It repeatedly executes a statement as long as a condition is
-true.  It looks like this:
-
-@example
-while (@var{condition})
-  @var{body}
-@end example
-
-@noindent
-Here @var{body} is a statement that we call the @dfn{body} of the loop,
-and @var{condition} is an expression that controls how long the loop
-keeps running.
-
-The first thing the @code{while} statement does is test @var{condition}.
-If @var{condition} is true, it executes the statement @var{body}.
-(@var{condition} is true when the value 
-is not zero and not a null string.)  After @var{body} has been executed,
-@var{condition} is tested again, and if it is still true, @var{body} is
-executed again.  This process repeats until @var{condition} is no longer
-true.  If @var{condition} is initially false, the body of the loop is
-never executed.@refill
-
-This example prints the first three fields of each record, one per line.
-
-@example
-awk '@{ i = 1
-       while (i <= 3) @{
-           print $i
-           i++
-       @}
-@}'
-@end example
-
-@noindent
-Here the body of the loop is a compound statement enclosed in braces,
-containing two statements.
-
-The loop works like this: first, the value of @code{i} is set to 1.
-Then, the @code{while} tests whether @code{i} is less than or equal to
-three.  This is the case when @code{i} equals one, so the @code{i}-th
-field is printed.  Then the @code{i++} increments the value of @code{i}
-and the loop repeats.  The loop terminates when @code{i} reaches 4.
-
-As you can see, a newline is not required between the condition and the
-body; but using one makes the program clearer unless the body is a
-compound statement or is very simple.  The newline after the open-brace
-that begins the compound statement is not required either, but the
-program would be hard to read without it.
-
-@node Do Statement, For Statement, While Statement, Statements
-@section The @code{do}-@code{while} Statement
-
-The @code{do} loop is a variation of the @code{while} looping statement.
-The @code{do} loop executes the @var{body} once, then repeats @var{body}
-as long as @var{condition} is true.  It looks like this:
-
-@example
-do
-  @var{body}
-while (@var{condition})
-@end example
-
-Even if @var{condition} is false at the start, @var{body} is executed at
-least once (and only once, unless executing @var{body} makes
-@var{condition} true).  Contrast this with the corresponding
-@code{while} statement:
-
-@example
-while (@var{condition})
-  @var{body}
-@end example
-
-@noindent
-This statement does not execute @var{body} even once if @var{condition}
-is false to begin with.
-
-Here is an example of a @code{do} statement:
-
-@example
-awk '@{ i = 1
-       do @{
-          print $0
-          i++
-       @} while (i <= 10)
-@}'
-@end example
-
-@noindent
-prints each input record ten times.  It isn't a very realistic example,
-since in this case an ordinary @code{while} would do just as well.  But
-this reflects actual experience; there is only occasionally a real use
-for a @code{do} statement.@refill
-
-@node For Statement, Break Statement, Do Statement, Statements
-@section The @code{for} Statement
-@cindex @code{for} statement
-
-The @code{for} statement makes it more convenient to count iterations of a
-loop.  The general form of the @code{for} statement looks like this:@refill
-
-@example
-for (@var{initialization}; @var{condition}; @var{increment})
-  @var{body}
-@end example
-
-@noindent
-This statement starts by executing @var{initialization}.  Then, as long
-as @var{condition} is true, it repeatedly executes @var{body} and then
-@var{increment}.  Typically @var{initialization} sets a variable to
-either zero or one, @var{increment} adds 1 to it, and @var{condition}
-compares it against the desired number of iterations.
-
-Here is an example of a @code{for} statement:
-
-@example
-@group
-awk '@{ for (i = 1; i <= 3; i++)
-          print $i
-@}'
-@end group
-@end example
-
-@noindent
-This prints the first three fields of each input record, one field per
-line.
-
-In the @code{for} statement, @var{body} stands for any statement, but
-@var{initialization}, @var{condition} and @var{increment} are just
-expressions.  You cannot set more than one variable in the
-@var{initialization} part unless you use a multiple assignment statement
-such as @code{x = y = 0}, which is possible only if all the initial values
-are equal.  (But you can initialize additional variables by writing
-their assignments as separate statements preceding the @code{for} loop.)
-
-The same is true of the @var{increment} part; to increment additional
-variables, you must write separate statements at the end of the loop.
-The C compound expression, using C's comma operator, would be useful in
-this context, but it is not supported in @code{awk}.
-
-Most often, @var{increment} is an increment expression, as in the
-example above.  But this is not required; it can be any expression
-whatever.  For example, this statement prints all the powers of 2
-between 1 and 100:
-
-@example
-for (i = 1; i <= 100; i *= 2)
-  print i
-@end example
-
-Any of the three expressions in the parentheses following the @code{for} may
-be omitted if there is nothing to be done there.  Thus, @w{@samp{for (;x
-> 0;)}} is equivalent to @w{@samp{while (x > 0)}}.  If the
-@var{condition} is omitted, it is treated as @var{true}, effectively
-yielding an @dfn{infinite loop} (i.e., a loop that will never
-terminate).@refill
-
-In most cases, a @code{for} loop is an abbreviation for a @code{while}
-loop, as shown here:
-
-@example
-@var{initialization}
-while (@var{condition}) @{
-  @var{body}
-  @var{increment}
-@}
-@end example
-
-@noindent
-The only exception is when the @code{continue} statement
-(@pxref{Continue Statement, ,The @code{continue} Statement}) is used
-inside the loop; changing a @code{for} statement to a @code{while}
-statement in this way can change the effect of the @code{continue}
-statement inside the loop.@refill
-
-There is an alternate version of the @code{for} loop, for iterating over
-all the indices of an array:
-
-@example
-for (i in array)
-    @var{do something with} array[i]
-@end example
-
-@noindent
-@xref{Arrays, ,Arrays in @code{awk}}, for more information on this
-version of the @code{for} loop.
-
-The @code{awk} language has a @code{for} statement in addition to a
-@code{while} statement because often a @code{for} loop is both less work to
-type and more natural to think of.  Counting the number of iterations is
-very common in loops.  It can be easier to think of this counting as part
-of looping rather than as something to do inside the loop.
-
-The next section has more complicated examples of @code{for} loops.
-
-@node Break Statement, Continue Statement, For Statement, Statements
-@section The @code{break} Statement
-@cindex @code{break} statement
-@cindex loops, exiting
-
-The @code{break} statement jumps out of the innermost @code{for},
-@code{while}, or @code{do}-@code{while} loop that encloses it.  The
-following example finds the smallest divisor of any integer, and also
-identifies prime numbers:@refill
-
-@smallexample
-awk '# find smallest divisor of num
-     @{ num = $1
-       for (div = 2; div*div <= num; div++)
-         if (num % div == 0)
-           break
-       if (num % div == 0)
-         printf "Smallest divisor of %d is %d\n", num, div
-       else
-         printf "%d is prime\n", num  @}'
-@end smallexample
-
-When the remainder is zero in the first @code{if} statement, @code{awk}
-immediately @dfn{breaks out} of the containing @code{for} loop.  This means
-that @code{awk} proceeds immediately to the statement following the loop
-and continues processing.  (This is very different from the @code{exit}
-statement which stops the entire @code{awk} program.  
-@xref{Exit Statement, ,The @code{exit} Statement}.)@refill
-
-Here is another program equivalent to the previous one.  It illustrates how
-the @var{condition} of a @code{for} or @code{while} could just as well be
-replaced with a @code{break} inside an @code{if}:
-
-@smallexample
-@group
-awk '# find smallest divisor of num
-     @{ num = $1
-       for (div = 2; ; div++) @{
-         if (num % div == 0) @{
-           printf "Smallest divisor of %d is %d\n", num, div
-           break
-         @}
-         if (div*div > num) @{
-           printf "%d is prime\n", num
-           break
-         @}
-       @}
-@}'
-@end group
-@end smallexample
-
-@node Continue Statement, Next Statement, Break Statement, Statements
-@section The @code{continue} Statement
-
-@cindex @code{continue} statement
-The @code{continue} statement, like @code{break}, is used only inside
-@code{for}, @code{while}, and @code{do}-@code{while} loops.  It skips
-over the rest of the loop body, causing the next cycle around the loop
-to begin immediately.  Contrast this with @code{break}, which jumps out
-of the loop altogether.  Here is an example:@refill
-
-@example
-# print names that don't contain the string "ignore"
-
-# first, save the text of each line
-@{ names[NR] = $0 @}
-
-# print what we're interested in
-END @{
-   for (x in names) @{
-       if (names[x] ~ /ignore/)
-           continue
-       print names[x]
-   @}
-@}
-@end example
-
-If one of the input records contains the string @samp{ignore}, this
-example skips the print statement for that record, and continues back to
-the first statement in the loop.
-
-This is not a practical example of @code{continue}, since it would be
-just as easy to write the loop like this:
-
-@example
-for (x in names)
-  if (names[x] !~ /ignore/)
-    print names[x]
-@end example
-
-@ignore
-from brennan@boeing.com:
-
-page 90, section 9.6.  The example is too artificial as
-the one line program
-
-	!/ignore/
-
-does the same thing.
-@end ignore
-@c ADR --- he's right, but don't worry about this for now
-
-The @code{continue} statement in a @code{for} loop directs @code{awk} to
-skip the rest of the body of the loop, and resume execution with the
-increment-expression of the @code{for} statement.  The following program
-illustrates this fact:@refill
-
-@example
-awk 'BEGIN @{
-     for (x = 0; x <= 20; x++) @{
-         if (x == 5)
-             continue
-         printf ("%d ", x)
-     @}
-     print ""
-@}'
-@end example
-
-@noindent
-This program prints all the numbers from 0 to 20, except for 5, for
-which the @code{printf} is skipped.  Since the increment @code{x++}
-is not skipped, @code{x} does not remain stuck at 5.  Contrast the
-@code{for} loop above with the @code{while} loop:
-
-@example
-awk 'BEGIN @{
-     x = 0
-     while (x <= 20) @{
-         if (x == 5)
-             continue
-         printf ("%d ", x)
-         x++
-     @}
-     print ""
-@}'
-@end example
-
-@noindent
-This program loops forever once @code{x} gets to 5.
-
-As described above, the @code{continue} statement has no meaning when
-used outside the body of a loop.  However, although it was never documented,
-historical implementations of @code{awk} have treated the @code{continue}
-statement outside of a loop as if it were a @code{next} statement
-(@pxref{Next Statement, ,The @code{next} Statement}).  
-By default, @code{gawk} silently supports this usage.  However, if
-@samp{-W posix} has been specified on the command line
-(@pxref{Command Line, ,Invoking @code{awk}}),
-it will be treated as an error, since the @sc{posix} standard specifies
-that @code{continue} should only be used inside the body of a loop.@refill
-
-@node Next Statement, Next File Statement, Continue Statement, Statements
-@section The @code{next} Statement
-@cindex @code{next} statement
-
-The @code{next} statement forces @code{awk} to immediately stop processing
-the current record and go on to the next record.  This means that no
-further rules are executed for the current record.  The rest of the
-current rule's action is not executed either.
-
-Contrast this with the effect of the @code{getline} function
-(@pxref{Getline, ,Explicit Input with @code{getline}}).  That too causes
-@code{awk} to read the next record immediately, but it does not alter the
-flow of control in any way.  So the rest of the current action executes
-with a new input record.
-
-At the highest level, @code{awk} program execution is a loop that reads
-an input record and then tests each rule's pattern against it.  If you
-think of this loop as a @code{for} statement whose body contains the
-rules, then the @code{next} statement is analogous to a @code{continue}
-statement: it skips to the end of the body of this implicit loop, and
-executes the increment (which reads another record).
-
-For example, if your @code{awk} program works only on records with four
-fields, and you don't want it to fail when given bad input, you might
-use this rule near the beginning of the program:
-
-@smallexample
-NF != 4 @{
-  printf("line %d skipped: doesn't have 4 fields", FNR) > "/dev/stderr"
-  next
-@}
-@end smallexample
-
-@noindent
-so that the following rules will not see the bad record.  The error
-message is redirected to the standard error output stream, as error
-messages should be.  @xref{Special Files, ,Standard I/O Streams}.
-
-According to the @sc{posix} standard, the behavior is undefined if
-the @code{next} statement is used in a @code{BEGIN} or @code{END} rule.
-@code{gawk} will treat it as a syntax error.
-
-If the @code{next} statement causes the end of the input to be reached,
-then the code in the @code{END} rules, if any, will be executed.
-@xref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}.
-
-@node Next File Statement, Exit Statement, Next Statement, Statements
-@section The @code{next file} Statement
-
-@cindex @code{next file} statement
-The @code{next file} statement is similar to the @code{next} statement.
-However, instead of abandoning processing of the current record, the
-@code{next file} statement instructs @code{awk} to stop processing the
-current data file.
-
-Upon execution of the @code{next file} statement, @code{FILENAME} is
-updated to the name of the next data file listed on the command line,
-@code{FNR} is reset to 1, and processing starts over with the first
-rule in the progam.  @xref{Built-in Variables}.
-
-If the @code{next file} statement causes the end of the input to be reached,
-then the code in the @code{END} rules, if any, will be executed.
-@xref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}.
-
-The @code{next file} statement is a @code{gawk} extension; it is not
-(currently) available in any other @code{awk} implementation.  You can
-simulate its behavior by creating a library file named @file{nextfile.awk},
-with the following contents.  (This sample program uses user-defined
-functions, a feature that has not been presented yet.
-@xref{User-defined, ,User-defined Functions},
-for more information.)@refill
-
-@smallexample
-# nextfile --- function to skip remaining records in current file
-
-# this should be read in before the "main" awk program
-
-function nextfile() @{ _abandon_ = FILENAME; next @}
-
-_abandon_ == FILENAME && FNR > 1   @{ next @}
-_abandon_ == FILENAME && FNR == 1  @{ _abandon_ = "" @}
-@end smallexample
-
-The @code{nextfile} function simply sets a ``private'' variable@footnote{Since
-all variables in @code{awk} are global, this program uses the common
-practice of prefixing the variable name with an underscore.  In fact, it
-also suffixes the variable name with an underscore, as extra insurance
-against using a variable name that might be used in some other library
-file.} to the name of the current data file, and then retrieves the next
-record.  Since this file is read before the main @code{awk} program,
-the rules that follows the function definition will be executed before the
-rules in the main program.  The first rule continues to skip records as long as
-the name of the input file has not changed, and this is not the first
-record in the file.  This rule is sufficient most of the time.  But what if
-the @emph{same} data file is named twice in a row on the command line?
-This rule would not process the data file the second time.  The second rule
-catches this case: If the data file name is what was being skipped, but
-@code{FNR} is 1, then this is the second time the file is being processed,
-and it should not be skipped.
-
-The @code{next file} statement would be useful if you have many data
-files to process, and due to the nature of the data, you expect that you
-would not want to process every record in the file.  In order to move on to
-the next data file, you would have to continue scanning the unwanted
-records (as described above).  The @code{next file} statement accomplishes
-this much more efficiently.
-
-@ignore
-Would it make sense down the road to nuke `next file' in favor of
-semantics that would make this work?
-
-        function nextfile() { ARGIND++ ; next }
-@end ignore
-
-@node Exit Statement,  , Next File Statement, Statements
-@section The @code{exit} Statement
-
-@cindex @code{exit} statement
-The @code{exit} statement causes @code{awk} to immediately stop
-executing the current rule and to stop processing input; any remaining input
-is ignored.@refill
-
-If an @code{exit} statement is executed from a @code{BEGIN} rule the
-program stops processing everything immediately.  No input records are
-read.  However, if an @code{END} rule is present, it is executed
-(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}).
-
-If @code{exit} is used as part of an @code{END} rule, it causes
-the program to stop immediately.
-
-An @code{exit} statement that is part of an ordinary rule (that is, not part
-of a @code{BEGIN} or @code{END} rule) stops the execution of any further
-automatic rules, but the @code{END} rule is executed if there is one.
-If you do not want the @code{END} rule to do its job in this case, you
-can set a variable to nonzero before the @code{exit} statement, and check
-that variable in the @code{END} rule.
-
-If an argument is supplied to @code{exit}, its value is used as the exit
-status code for the @code{awk} process.  If no argument is supplied,
-@code{exit} returns status zero (success).@refill
-
-For example, let's say you've discovered an error condition you really
-don't know how to handle.  Conventionally, programs report this by
-exiting with a nonzero status.  Your @code{awk} program can do this
-using an @code{exit} statement with a nonzero argument.  Here's an
-example of this:@refill
-
-@example
-@group
-BEGIN @{
-       if (("date" | getline date_now) < 0) @{
-         print "Can't get system date" > "/dev/stderr"
-         exit 4
-       @}
-@}
-@end group
-@end example
-
-@node Arrays, Built-in, Statements, Top
-@chapter Arrays in @code{awk}
-
-An @dfn{array} is a table of values, called @dfn{elements}.  The
-elements of an array are distinguished by their indices.  @dfn{Indices}
-may be either numbers or strings.  Each array has a name, which looks
-like a variable name, but must not be in use as a variable name in the
-same @code{awk} program.
-
-@menu
-* Array Intro::                 Introduction to Arrays
-* Reference to Elements::       How to examine one element of an array.
-* Assigning Elements::          How to change an element of an array.
-* Array Example::               Basic Example of an Array
-* Scanning an Array::           A variation of the @code{for} statement.  
-                                It loops through the indices of 
-                                an array's existing elements.
-* Delete::                      The @code{delete} statement removes 
-                                an element from an array.
-* Numeric Array Subscripts::    How to use numbers as subscripts in @code{awk}.
-* Multi-dimensional::           Emulating multi-dimensional arrays in @code{awk}.
-* Multi-scanning::              Scanning multi-dimensional arrays.
-@end menu
-
-@node Array Intro, Reference to Elements, Arrays, Arrays
-@section Introduction to Arrays
-
-@cindex arrays
-The @code{awk} language has one-dimensional @dfn{arrays} for storing groups
-of related strings or numbers.
-
-Every @code{awk} array must have a name.  Array names have the same
-syntax as variable names; any valid variable name would also be a valid
-array name.  But you cannot use one name in both ways (as an array and
-as a variable) in one @code{awk} program.
-
-Arrays in @code{awk} superficially resemble arrays in other programming
-languages; but there are fundamental differences.  In @code{awk}, you
-don't need to specify the size of an array before you start to use it.
-Additionally, any number or string in @code{awk} may be used as an
-array index.
-
-In most other languages, you have to @dfn{declare} an array and specify
-how many elements or components it contains.  In such languages, the
-declaration causes a contiguous block of memory to be allocated for that
-many elements.  An index in the array must be a positive integer; for
-example, the index 0 specifies the first element in the array, which is
-actually stored at the beginning of the block of memory.  Index 1
-specifies the second element, which is stored in memory right after the
-first element, and so on.  It is impossible to add more elements to the
-array, because it has room for only as many elements as you declared.
-
-A contiguous array of four elements might look like this,
-conceptually, if the element values are @code{8}, @code{"foo"},
-@code{""} and @code{30}:@refill
-
-@example
-+---------+---------+--------+---------+
-|    8    |  "foo"  |   ""   |    30   |    @r{value}
-+---------+---------+--------+---------+
-     0         1         2         3        @r{index}
-@end example
-
-@noindent
-Only the values are stored; the indices are implicit from the order of
-the values.  @code{8} is the value at index 0, because @code{8} appears in the
-position with 0 elements before it.
-
-@cindex arrays, definition of
-@cindex associative arrays
-Arrays in @code{awk} are different: they are @dfn{associative}.  This means
-that each array is a collection of pairs: an index, and its corresponding
-array element value:
-
-@example
-@r{Element} 4     @r{Value} 30
-@r{Element} 2     @r{Value} "foo"
-@r{Element} 1     @r{Value} 8
-@r{Element} 3     @r{Value} ""
-@end example
-
-@noindent
-We have shown the pairs in jumbled order because their order is irrelevant.
-
-One advantage of an associative array is that new pairs can be added
-at any time.  For example, suppose we add to the above array a tenth element
-whose value is @w{@code{"number ten"}}.  The result is this:
-
-@example
-@r{Element} 10    @r{Value} "number ten"
-@r{Element} 4     @r{Value} 30
-@r{Element} 2     @r{Value} "foo"
-@r{Element} 1     @r{Value} 8
-@r{Element} 3     @r{Value} ""
-@end example
-
-@noindent
-Now the array is @dfn{sparse} (i.e., some indices are missing): it has
-elements 1--4 and 10, but doesn't have elements 5, 6, 7, 8, or 9.@refill
-
-Another consequence of associative arrays is that the indices don't
-have to be positive integers.  Any number, or even a string, can be
-an index.  For example, here is an array which translates words from
-English into French:
-
-@example
-@r{Element} "dog" @r{Value} "chien"
-@r{Element} "cat" @r{Value} "chat"
-@r{Element} "one" @r{Value} "un"
-@r{Element} 1     @r{Value} "un"
-@end example
-
-@noindent
-Here we decided to translate the number 1 in both spelled-out and
-numeric form---thus illustrating that a single array can have both
-numbers and strings as indices.
-
-When @code{awk} creates an array for you, e.g., with the @code{split}
-built-in function,
-that array's indices are consecutive integers starting at 1.
-(@xref{String Functions, ,Built-in Functions for String Manipulation}.)
-
-@node Reference to Elements, Assigning Elements, Array Intro, Arrays
-@section Referring to an Array Element
-@cindex array reference
-@cindex element of array
-@cindex reference to array
-
-The principal way of using an array is to refer to one of its elements.
-An array reference is an expression which looks like this:
-
-@example
-@var{array}[@var{index}]
-@end example
-
-@noindent
-Here, @var{array} is the name of an array.  The expression @var{index} is
-the index of the element of the array that you want.
-
-The value of the array reference is the current value of that array
-element.  For example, @code{foo[4.3]} is an expression for the element
-of array @code{foo} at index 4.3.
-
-If you refer to an array element that has no recorded value, the value
-of the reference is @code{""}, the null string.  This includes elements
-to which you have not assigned any value, and elements that have been
-deleted (@pxref{Delete, ,The @code{delete} Statement}).  Such a reference
-automatically creates that array element, with the null string as its value.
-(In some cases, this is unfortunate, because it might waste memory inside
-@code{awk}).
-
-@cindex arrays, presence of elements
-You can find out if an element exists in an array at a certain index with
-the expression:
-
-@example
-@var{index} in @var{array}
-@end example
-
-@noindent
-This expression tests whether or not the particular index exists,
-without the side effect of creating that element if it is not present.
-The expression has the value 1 (true) if @code{@var{array}[@var{index}]}
-exists, and 0 (false) if it does not exist.@refill
-
-For example, to test whether the array @code{frequencies} contains the
-index @code{"2"}, you could write this statement:@refill
-
-@smallexample
-if ("2" in frequencies) print "Subscript \"2\" is present."
-@end smallexample
-
-Note that this is @emph{not} a test of whether or not the array
-@code{frequencies} contains an element whose @emph{value} is @code{"2"}.
-(There is no way to do that except to scan all the elements.)  Also, this
-@emph{does not} create @code{frequencies["2"]}, while the following
-(incorrect) alternative would do so:@refill
-
-@smallexample
-if (frequencies["2"] != "") print "Subscript \"2\" is present."
-@end smallexample
-
-@node Assigning Elements, Array Example, Reference to Elements, Arrays
-@section Assigning Array Elements
-@cindex array assignment
-@cindex element assignment
-
-Array elements are lvalues: they can be assigned values just like
-@code{awk} variables:
-
-@example
-@var{array}[@var{subscript}] = @var{value}
-@end example
-
-@noindent
-Here @var{array} is the name of your array.  The expression
-@var{subscript} is the index of the element of the array that you want
-to assign a value.  The expression @var{value} is the value you are
-assigning to that element of the array.@refill
-
-@node Array Example, Scanning an Array, Assigning Elements, Arrays
-@section Basic Example of an Array
-
-The following program takes a list of lines, each beginning with a line
-number, and prints them out in order of line number.  The line numbers are
-not in order, however, when they are first read:  they are scrambled.  This
-program sorts the lines by making an array using the line numbers as
-subscripts.  It then prints out the lines in sorted order of their numbers.
-It is a very simple program, and gets confused if it encounters repeated
-numbers, gaps, or lines that don't begin with a number.@refill
-
-@example
-@{
-  if ($1 > max)
-    max = $1
-  arr[$1] = $0
-@}
-
-END @{
-  for (x = 1; x <= max; x++)
-    print arr[x]
-@}
-@end example
-
-The first rule keeps track of the largest line number seen so far;
-it also stores each line into the array @code{arr}, at an index that
-is the line's number.
-
-The second rule runs after all the input has been read, to print out
-all the lines.
-
-When this program is run with the following input:
-
-@example
-5  I am the Five man
-2  Who are you?  The new number two!
-4  . . . And four on the floor
-1  Who is number one?
-3  I three you.
-@end example
-
-@noindent
-its output is this:
-
-@example
-1  Who is number one?
-2  Who are you?  The new number two!
-3  I three you.
-4  . . . And four on the floor
-5  I am the Five man
-@end example
-
-If a line number is repeated, the last line with a given number overrides
-the others.
-
-Gaps in the line numbers can be handled with an easy improvement to the
-program's @code{END} rule:
-
-@example
-END @{
-  for (x = 1; x <= max; x++)
-    if (x in arr)
-      print arr[x]
-@}
-@end example
-
-@node Scanning an Array, Delete, Array Example, Arrays
-@section Scanning all Elements of an Array
-@cindex @code{for (x in @dots{})}
-@cindex arrays, special @code{for} statement
-@cindex scanning an array
-
-In programs that use arrays, often you need a loop that executes
-once for each element of an array.  In other languages, where arrays are
-contiguous and indices are limited to positive integers, this is
-easy: the largest index is one less than the length of the array, and you can
-find all the valid indices by counting from zero up to that value.  This
-technique won't do the job in @code{awk}, since any number or string
-may be an array index.  So @code{awk} has a special kind of @code{for}
-statement for scanning an array:
-
-@example
-for (@var{var} in @var{array})
-  @var{body}
-@end example
-
-@noindent
-This loop executes @var{body} once for each different value that your
-program has previously used as an index in @var{array}, with the
-variable @var{var} set to that index.@refill
-
-Here is a program that uses this form of the @code{for} statement.  The
-first rule scans the input records and notes which words appear (at
-least once) in the input, by storing a 1 into the array @code{used} with
-the word as index.  The second rule scans the elements of @code{used} to
-find all the distinct words that appear in the input.  It prints each
-word that is more than 10 characters long, and also prints the number of
-such words.  @xref{Built-in, ,Built-in Functions}, for more information
-on the built-in function @code{length}.
-
-@smallexample
-# Record a 1 for each word that is used at least once.
-@{
-  for (i = 1; i <= NF; i++)
-    used[$i] = 1
-@}
-
-# Find number of distinct words more than 10 characters long.
-END @{
-  for (x in used)
-    if (length(x) > 10) @{
-      ++num_long_words
-      print x
-  @}
-  print num_long_words, "words longer than 10 characters"
-@}
-@end smallexample
-
-@noindent
-@xref{Sample Program}, for a more detailed example of this type.
-
-The order in which elements of the array are accessed by this statement
-is determined by the internal arrangement of the array elements within
-@code{awk} and cannot be controlled or changed.  This can lead to
-problems if new elements are added to @var{array} by statements in
-@var{body}; you cannot predict whether or not the @code{for} loop will
-reach them.  Similarly, changing @var{var} inside the loop can produce
-strange results.  It is best to avoid such things.@refill
-
-@node Delete, Numeric Array Subscripts, Scanning an Array, Arrays
-@section The @code{delete} Statement
-@cindex @code{delete} statement
-@cindex deleting elements of arrays
-@cindex removing elements of arrays
-@cindex arrays, deleting an element
-
-You can remove an individual element of an array using the @code{delete}
-statement:
-
-@example
-delete @var{array}[@var{index}]
-@end example
-
-You can not refer to an array element after it has been deleted;
-it is as if you had never referred
-to it and had never given it any value.  You can no longer obtain any
-value the element once had.
-
-Here is an example of deleting elements in an array:
-
-@example
-for (i in frequencies)
-  delete frequencies[i]
-@end example
-
-@noindent
-This example removes all the elements from the array @code{frequencies}.
-
-If you delete an element, a subsequent @code{for} statement to scan the array
-will not report that element, and the @code{in} operator to check for
-the presence of that element will return 0:
-
-@example
-delete foo[4]
-if (4 in foo)
-  print "This will never be printed"
-@end example
-
-It is not an error to delete an element which does not exist.
-
-@node Numeric Array Subscripts, Multi-dimensional, Delete, Arrays
-@section Using Numbers to Subscript Arrays
-
-An important aspect of arrays to remember is that array subscripts
-are @emph{always} strings.  If you use a numeric value as a subscript,
-it will be converted to a string value before it is used for subscripting
-(@pxref{Conversion, ,Conversion of Strings and Numbers}).
-
-@cindex conversions, during subscripting
-@cindex numbers, used as subscripts
-@vindex CONVFMT
-This means that the value of the @code{CONVFMT} can potentially
-affect how your program accesses elements of an array.  For example:
-
-@example
-a = b = 12.153
-data[a] = 1
-CONVFMT = "%2.2f"
-if (b in data)
-    printf "%s is in data", b
-else
-    printf "%s is not in data", b
-@end example
-
-@noindent
-should print @samp{12.15 is not in data}.  The first statement gives
-both @code{a} and @code{b} the same numeric value.  Assigning to
-@code{data[a]} first gives @code{a} the string value @code{"12.153"}
-(using the default conversion value of @code{CONVFMT}, @code{"%.6g"}),
-and then assigns 1 to @code{data["12.153"]}.  The program then changes
-the value of @code{CONVFMT}.  The test @samp{(b in data)} forces @code{b}
-to be converted to a string, this time @code{"12.15"}, since the value of
-@code{CONVFMT} only allows two significant digits.  This test fails,
-since @code{"12.15"} is a different string from @code{"12.153"}.@refill
-
-According to the rules for conversions
-(@pxref{Conversion, ,Conversion of Strings and Numbers}), integer
-values are always converted to strings as integers, no matter what the
-value of @code{CONVFMT} may happen to be.  So the usual case of@refill
-
-@example
-for (i = 1; i <= maxsub; i++)
-    @i{do something with} array[i]
-@end example
-
-@noindent
-will work, no matter what the value of @code{CONVFMT}.
-
-Like many things in @code{awk}, the majority of the time things work
-as you would expect them to work.  But it is useful to have a precise
-knowledge of the actual rules, since sometimes they can have a subtle
-effect on your programs.
-
-@node Multi-dimensional, Multi-scanning, Numeric Array Subscripts, Arrays
-@section Multi-dimensional Arrays
-
-@c the following index entry is an overfull hbox.  --mew 30jan1992
-@cindex subscripts in arrays
-@cindex arrays, multi-dimensional subscripts
-@cindex multi-dimensional subscripts
-A multi-dimensional array is an array in which an element is identified
-by a sequence of indices, not a single index.  For example, a
-two-dimensional array requires two indices.  The usual way (in most
-languages, including @code{awk}) to refer to an element of a
-two-dimensional array named @code{grid} is with
-@code{grid[@var{x},@var{y}]}.
-
-@vindex SUBSEP
-Multi-dimensional arrays are supported in @code{awk} through
-concatenation of indices into one string.  What happens is that
-@code{awk} converts the indices into strings
-(@pxref{Conversion, ,Conversion of Strings and Numbers}) and
-concatenates them together, with a separator between them.  This creates
-a single string that describes the values of the separate indices.  The
-combined string is used as a single index into an ordinary,
-one-dimensional array.  The separator used is the value of the built-in
-variable @code{SUBSEP}.@refill
-
-For example, suppose we evaluate the expression @code{foo[5,12]="value"}
-when the value of @code{SUBSEP} is @code{"@@"}.  The numbers 5 and 12 are
-converted to strings and
-concatenated with an @samp{@@} between them, yielding @code{"5@@12"}; thus,
-the array element @code{foo["5@@12"]} is set to @code{"value"}.@refill
-
-Once the element's value is stored, @code{awk} has no record of whether
-it was stored with a single index or a sequence of indices.  The two
-expressions @code{foo[5,12]} and @w{@code{foo[5 SUBSEP 12]}} always have
-the same value.
-
-The default value of @code{SUBSEP} is the string @code{"\034"},
-which contains a nonprinting character that is unlikely to appear in an
-@code{awk} program or in the input data.
-
-The usefulness of choosing an unlikely character comes from the fact
-that index values that contain a string matching @code{SUBSEP} lead to
-combined strings that are ambiguous.  Suppose that @code{SUBSEP} were
-@code{"@@"}; then @w{@code{foo["a@@b", "c"]}} and @w{@code{foo["a",
-"b@@c"]}} would be indistinguishable because both would actually be
-stored as @code{foo["a@@b@@c"]}.  Because @code{SUBSEP} is
-@code{"\034"}, such confusion can arise only when an index
-contains the character with ASCII code 034, which is a rare
-event.@refill
-
-You can test whether a particular index-sequence exists in a
-``multi-dimensional'' array with the same operator @code{in} used for single
-dimensional arrays.  Instead of a single index as the left-hand operand,
-write the whole sequence of indices, separated by commas, in
-parentheses:@refill
-
-@example
-(@var{subscript1}, @var{subscript2}, @dots{}) in @var{array}
-@end example
-
-The following example treats its input as a two-dimensional array of
-fields; it rotates this array 90 degrees clockwise and prints the
-result.  It assumes that all lines have the same number of
-elements.
-
-@example
-awk '@{
-     if (max_nf < NF)
-          max_nf = NF
-     max_nr = NR
-     for (x = 1; x <= NF; x++)
-          vector[x, NR] = $x
-@}
-
-END @{
-     for (x = 1; x <= max_nf; x++) @{
-          for (y = max_nr; y >= 1; --y)
-               printf("%s ", vector[x, y])
-          printf("\n")
-     @}
-@}'
-@end example
-
-@noindent
-When given the input:
-
-@example
-@group
-1 2 3 4 5 6
-2 3 4 5 6 1
-3 4 5 6 1 2
-4 5 6 1 2 3
-@end group
-@end example
-
-@noindent
-it produces:
-
-@example
-@group
-4 3 2 1
-5 4 3 2
-6 5 4 3
-1 6 5 4
-2 1 6 5
-3 2 1 6
-@end group
-@end example
-
-@node Multi-scanning,  , Multi-dimensional, Arrays
-@section Scanning Multi-dimensional Arrays
-
-There is no special @code{for} statement for scanning a
-``multi-dimensional'' array; there cannot be one, because in truth there
-are no multi-dimensional arrays or elements; there is only a
-multi-dimensional @emph{way of accessing} an array.
-
-However, if your program has an array that is always accessed as
-multi-dimensional, you can get the effect of scanning it by combining
-the scanning @code{for} statement
-(@pxref{Scanning an Array, ,Scanning all Elements of an Array}) with the
-@code{split} built-in function
-(@pxref{String Functions, ,Built-in Functions for String Manipulation}).
-It works like this:@refill
-
-@example
-for (combined in @var{array}) @{
-  split(combined, separate, SUBSEP)
-  @dots{}
-@}
-@end example
-
-@noindent
-This finds each concatenated, combined index in the array, and splits it
-into the individual indices by breaking it apart where the value of
-@code{SUBSEP} appears.  The split-out indices become the elements of
-the array @code{separate}.
-
-Thus, suppose you have previously stored in @code{@var{array}[1,
-"foo"]}; then an element with index @code{"1\034foo"} exists in
-@var{array}.  (Recall that the default value of @code{SUBSEP} contains
-the character with code 034.)  Sooner or later the @code{for} statement
-will find that index and do an iteration with @code{combined} set to
-@code{"1\034foo"}.  Then the @code{split} function is called as
-follows:
-
-@example
-split("1\034foo", separate, "\034")
-@end example
-
-@noindent
-The result of this is to set @code{separate[1]} to 1 and @code{separate[2]}
-to @code{"foo"}.  Presto, the original sequence of separate indices has
-been recovered.
-
-@node Built-in, User-defined, Arrays, Top
-@chapter Built-in Functions
-
-@cindex built-in functions
-@dfn{Built-in} functions are functions that are always available for
-your @code{awk} program to call.  This chapter defines all the built-in
-functions in @code{awk}; some of them are mentioned in other sections,
-but they are summarized here for your convenience.  (You can also define
-new functions yourself.  @xref{User-defined, ,User-defined Functions}.)
-
-@menu
-* Calling Built-in::            How to call built-in functions.
-* Numeric Functions::           Functions that work with numbers,
-                                including @code{int}, @code{sin} and @code{rand}.
-* String Functions::            Functions for string manipulation,
-                                such as @code{split}, @code{match}, and @code{sprintf}.
-* I/O Functions::               Functions for files and shell commands.
-* Time Functions::              Functions for dealing with time stamps.
-@end menu
-
-@node Calling Built-in, Numeric Functions, Built-in, Built-in
-@section Calling Built-in Functions
-
-To call a built-in function, write the name of the function followed
-by arguments in parentheses.  For example, @code{atan2(y + z, 1)}
-is a call to the function @code{atan2}, with two arguments.
-
-Whitespace is ignored between the built-in function name and the
-open-parenthesis, but we recommend that you avoid using whitespace
-there.  User-defined functions do not permit whitespace in this way, and
-you will find it easier to avoid mistakes by following a simple
-convention which always works: no whitespace after a function name.
-
-Each built-in function accepts a certain number of arguments.  In most
-cases, any extra arguments given to built-in functions are ignored.  The
-defaults for omitted arguments vary from function to function and are
-described under the individual functions.
-
-When a function is called, expressions that create the function's actual
-parameters are evaluated completely before the function call is performed.
-For example, in the code fragment:
-
-@example
-i = 4
-j = sqrt(i++)
-@end example
-
-@noindent
-the variable @code{i} is set to 5 before @code{sqrt} is called
-with a value of 4 for its actual parameter.
-
-@node Numeric Functions, String Functions, Calling Built-in, Built-in
-@section Numeric Built-in Functions
-@c I didn't make all the examples small because a couple of them were
-@c short already. --mew 29jan1992
-
-Here is a full list of built-in functions that work with numbers:
-
-@table @code
-@item int(@var{x})
-This gives you the integer part of @var{x}, truncated toward 0.  This
-produces the nearest integer to @var{x}, located between @var{x} and 0.
-
-For example, @code{int(3)} is 3, @code{int(3.9)} is 3, @code{int(-3.9)}
-is @minus{}3, and @code{int(-3)} is @minus{}3 as well.@refill
-
-@item sqrt(@var{x})
-This gives you the positive square root of @var{x}.  It reports an error
-if @var{x} is negative.  Thus, @code{sqrt(4)} is 2.@refill
-
-@item exp(@var{x})
-This gives you the exponential of @var{x}, or reports an error if
-@var{x} is out of range.  The range of values @var{x} can have depends
-on your machine's floating point representation.@refill
-
-@item log(@var{x})
-This gives you the natural logarithm of @var{x}, if @var{x} is positive;
-otherwise, it reports an error.@refill
-
-@item sin(@var{x})
-This gives you the sine of @var{x}, with @var{x} in radians.
-
-@item cos(@var{x})
-This gives you the cosine of @var{x}, with @var{x} in radians.
-
-@item atan2(@var{y}, @var{x})
-This gives you the arctangent of @code{@var{y} / @var{x}} in radians.
-
-@item rand()
-This gives you a random number.  The values of @code{rand} are
-uniformly-distributed between 0 and 1.  The value is never 0 and never
-1.
-
-Often you want random integers instead.  Here is a user-defined function
-you can use to obtain a random nonnegative integer less than @var{n}:
-
-@example
-function randint(n) @{
-     return int(n * rand())
-@}
-@end example
-
-@noindent
-The multiplication produces a random real number greater than 0 and less
-than @var{n}.  We then make it an integer (using @code{int}) between 0
-and @code{@var{n} @minus{} 1}.
-
-Here is an example where a similar function is used to produce
-random integers between 1 and @var{n}.  Note that this program will
-print a new random number for each input record.
-
-@smallexample
-awk '
-# Function to roll a simulated die.
-function roll(n) @{ return 1 + int(rand() * n) @}
-
-# Roll 3 six-sided dice and print total number of points.
-@{
-      printf("%d points\n", roll(6)+roll(6)+roll(6))
-@}'
-@end smallexample
-
-@strong{Note:} @code{rand} starts generating numbers from the same
-point, or @dfn{seed}, each time you run @code{awk}.  This means that
-a program will produce the same results each time you run it.
-The numbers are random within one @code{awk} run, but predictable
-from run to run.  This is convenient for debugging, but if you want
-a program to do different things each time it is used, you must change
-the seed to a value that will be different in each run.  To do this,
-use @code{srand}.
-
-@item srand(@var{x})
-The function @code{srand} sets the starting point, or @dfn{seed},
-for generating random numbers to the value @var{x}.
-
-Each seed value leads to a particular sequence of ``random'' numbers.
-Thus, if you set the seed to the same value a second time, you will get
-the same sequence of ``random'' numbers again.
-
-If you omit the argument @var{x}, as in @code{srand()}, then the current
-date and time of day are used for a seed.  This is the way to get random
-numbers that are truly unpredictable.
-
-The return value of @code{srand} is the previous seed.  This makes it
-easy to keep track of the seeds for use in consistently reproducing
-sequences of random numbers.
-@end table
-
-@node String Functions, I/O Functions, Numeric Functions, Built-in
-@section Built-in Functions for String Manipulation
-
-The functions in this section look at or change the text of one or more
-strings.
-
-@table @code
-@item index(@var{in}, @var{find})
-@findex match
-This searches the string @var{in} for the first occurrence of the string
-@var{find}, and returns the position in characters where that occurrence
-begins in the string @var{in}.  For example:@refill
-
-@smallexample
-awk 'BEGIN @{ print index("peanut", "an") @}'
-@end smallexample
-
-@noindent
-prints @samp{3}.  If @var{find} is not found, @code{index} returns 0.
-(Remember that string indices in @code{awk} start at 1.)
-
-@item length(@var{string})
-@findex length
-This gives you the number of characters in @var{string}.  If
-@var{string} is a number, the length of the digit string representing
-that number is returned.  For example, @code{length("abcde")} is 5.  By
-contrast, @code{length(15 * 35)} works out to 3.  How?  Well, 15 * 35 =
-525, and 525 is then converted to the string @samp{"525"}, which has
-three characters.
-
-If no argument is supplied, @code{length} returns the length of @code{$0}.
-
-In older versions of @code{awk}, you could call the @code{length} function
-without any parentheses.  Doing so is marked as ``deprecated'' in the
-@sc{posix} standard.  This means that while you can do this in your
-programs, it is a feature that can eventually be removed from a future
-version of the standard.  Therefore, for maximal portability of your
-@code{awk} programs you should always supply the parentheses.
-
-@item match(@var{string}, @var{regexp})
-@findex match
-The @code{match} function searches the string, @var{string}, for the
-longest, leftmost substring matched by the regular expression,
-@var{regexp}.  It returns the character position, or @dfn{index}, of
-where that substring begins (1, if it starts at the beginning of
-@var{string}).  If no match if found, it returns 0.
-
-@vindex RSTART
-@vindex RLENGTH
-The @code{match} function sets the built-in variable @code{RSTART} to
-the index.  It also sets the built-in variable @code{RLENGTH} to the
-length in characters of the matched substring.  If no match is found,
-@code{RSTART} is set to 0, and @code{RLENGTH} to @minus{}1.
-
-For example:
-
-@smallexample
-awk '@{
-       if ($1 == "FIND")
-         regex = $2
-       else @{
-         where = match($0, regex)
-         if (where)
-           print "Match of", regex, "found at", where, "in", $0
-       @}
-@}'
-@end smallexample
-
-@noindent
-This program looks for lines that match the regular expression stored in
-the variable @code{regex}.  This regular expression can be changed.  If the
-first word on a line is @samp{FIND}, @code{regex} is changed to be the
-second word on that line.  Therefore, given:
-
-@smallexample
-FIND fo*bar
-My program was a foobar
-But none of it would doobar
-FIND Melvin
-JF+KM
-This line is property of The Reality Engineering Co.
-This file created by Melvin.
-@end smallexample
-
-@noindent
-@code{awk} prints:
-
-@smallexample
-Match of fo*bar found at 18 in My program was a foobar
-Match of Melvin found at 26 in This file created by Melvin.
-@end smallexample
-
-@item split(@var{string}, @var{array}, @var{fieldsep})
-@findex split
-This divides @var{string} into pieces separated by @var{fieldsep},
-and stores the pieces in @var{array}.  The first piece is stored in
-@code{@var{array}[1]}, the second piece in @code{@var{array}[2]}, and so
-forth.  The string value of the third argument, @var{fieldsep}, is
-a regexp describing where to split @var{string} (much as @code{FS} can
-be a regexp describing where to split input records).  If
-the @var{fieldsep} is omitted, the value of @code{FS} is used.
-@code{split} returns the number of elements created.@refill
-
-The @code{split} function, then, splits strings into pieces in a
-manner similar to the way input lines are split into fields.  For example:
-
-@smallexample
-split("auto-da-fe", a, "-")
-@end smallexample
-
-@noindent
-splits the string @samp{auto-da-fe} into three fields using @samp{-} as the
-separator.  It sets the contents of the array @code{a} as follows:
-
-@smallexample
-a[1] = "auto"
-a[2] = "da"
-a[3] = "fe"
-@end smallexample
-
-@noindent
-The value returned by this call to @code{split} is 3.
-
-As with input field-splitting, when the value of @var{fieldsep} is
-@code{" "}, leading and trailing whitespace is ignored, and the elements
-are separated by runs of whitespace.
-
-@item sprintf(@var{format}, @var{expression1},@dots{})
-@findex sprintf
-This returns (without printing) the string that @code{printf} would
-have printed out with the same arguments
-(@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing}).
-For example:@refill
-
-@smallexample
-sprintf("pi = %.2f (approx.)", 22/7)
-@end smallexample
-
-@noindent
-returns the string @w{@code{"pi = 3.14 (approx.)"}}.
-
-@item sub(@var{regexp}, @var{replacement}, @var{target})
-@findex sub
-The @code{sub} function alters the value of @var{target}.
-It searches this value, which should be a string, for the
-leftmost substring matched by the regular expression, @var{regexp},
-extending this match as far as possible.  Then the entire string is
-changed by replacing the matched text with @var{replacement}.
-The modified string becomes the new value of @var{target}.
-
-This function is peculiar because @var{target} is not simply
-used to compute a value, and not just any expression will do: it
-must be a variable, field or array reference, so that @code{sub} can
-store a modified value there.  If this argument is omitted, then the
-default is to use and alter @code{$0}.
-
-For example:@refill
-
-@smallexample
-str = "water, water, everywhere"
-sub(/at/, "ith", str)
-@end smallexample
-
-@noindent
-sets @code{str} to @w{@code{"wither, water, everywhere"}}, by replacing the
-leftmost, longest occurrence of @samp{at} with @samp{ith}.
-
-The @code{sub} function returns the number of substitutions made (either
-one or zero).
-
-If the special character @samp{&} appears in @var{replacement}, it
-stands for the precise substring that was matched by @var{regexp}.  (If
-the regexp can match more than one string, then this precise substring
-may vary.)  For example:@refill
-
-@smallexample
-awk '@{ sub(/candidate/, "& and his wife"); print @}'
-@end smallexample
-
-@noindent
-changes the first occurrence of @samp{candidate} to @samp{candidate
-and his wife} on each input line.
-
-Here is another example:
-
-@smallexample
-awk 'BEGIN @{
-        str = "daabaaa"
-        sub(/a*/, "c&c", str)
-        print str
-@}'
-@end smallexample
-
-@noindent
-prints @samp{dcaacbaaa}.  This show how @samp{&} can represent a non-constant
-string, and also illustrates the ``leftmost, longest'' rule.
-
-The effect of this special character (@samp{&}) can be turned off by putting a
-backslash before it in the string.  As usual, to insert one backslash in
-the string, you must write two backslashes.  Therefore, write @samp{\\&}
-in a string constant to include a literal @samp{&} in the replacement.
-For example, here is how to replace the first @samp{|} on each line with
-an @samp{&}:@refill
-
-@smallexample
-awk '@{ sub(/\|/, "\\&"); print @}'
-@end smallexample
-
-@strong{Note:} as mentioned above, the third argument to @code{sub} must
-be an lvalue.  Some versions of @code{awk} allow the third argument to
-be an expression which is not an lvalue.  In such a case, @code{sub}
-would still search for the pattern and return 0 or 1, but the result of
-the substitution (if any) would be thrown away because there is no place
-to put it.  Such versions of @code{awk} accept expressions like
-this:@refill
-
-@smallexample
-sub(/USA/, "United States", "the USA and Canada")
-@end smallexample
-
-@noindent
-But that is considered erroneous in @code{gawk}.
-
-@item gsub(@var{regexp}, @var{replacement}, @var{target})
-@findex gsub
-This is similar to the @code{sub} function, except @code{gsub} replaces
-@emph{all} of the longest, leftmost, @emph{nonoverlapping} matching
-substrings it can find.  The @samp{g} in @code{gsub} stands for
-``global,'' which means replace everywhere.  For example:@refill
-
-@smallexample
-awk '@{ gsub(/Britain/, "United Kingdom"); print @}'
-@end smallexample
-
-@noindent
-replaces all occurrences of the string @samp{Britain} with @samp{United
-Kingdom} for all input records.@refill
-
-The @code{gsub} function returns the number of substitutions made.  If
-the variable to be searched and altered, @var{target}, is
-omitted, then the entire input record, @code{$0}, is used.@refill
-
-As in @code{sub}, the characters @samp{&} and @samp{\} are special, and
-the third argument must be an lvalue.
-
-@item substr(@var{string}, @var{start}, @var{length})
-@findex substr
-This returns a @var{length}-character-long substring of @var{string},
-starting at character number @var{start}.  The first character of a
-string is character number one.  For example,
-@code{substr("washington", 5, 3)} returns @code{"ing"}.@refill
-
-If @var{length} is not present, this function returns the whole suffix of
-@var{string} that begins at character number @var{start}.  For example,
-@code{substr("washington", 5)} returns @code{"ington"}.  This is also
-the case if @var{length} is greater than the number of characters remaining
-in the string, counting from character number @var{start}.
-
-@item tolower(@var{string})
-@findex tolower
-This returns a copy of @var{string}, with each upper-case character
-in the string replaced with its corresponding lower-case character.
-Nonalphabetic characters are left unchanged.  For example,
-@code{tolower("MiXeD cAsE 123")} returns @code{"mixed case 123"}.
-
-@item toupper(@var{string})
-@findex toupper
-This returns a copy of @var{string}, with each lower-case character
-in the string replaced with its corresponding upper-case character.
-Nonalphabetic characters are left unchanged.  For example,
-@code{toupper("MiXeD cAsE 123")} returns @code{"MIXED CASE 123"}.
-@end table
-
-@node I/O Functions, Time Functions, String Functions, Built-in
-@section Built-in Functions for Input/Output
-
-@table @code
-@item close(@var{filename})
-Close the file @var{filename}, for input or output.  The argument may
-alternatively be a shell command that was used for redirecting to or
-from a pipe; then the pipe is closed.
-
-@xref{Close Input, ,Closing Input Files and Pipes}, regarding closing
-input files and pipes.  @xref{Close Output, ,Closing Output Files and Pipes},
-regarding closing output files and pipes.@refill
-
-@item system(@var{command})
-@findex system
-@c the following index entry is an overfull hbox.  --mew 30jan1992
-@cindex interaction, @code{awk} and other programs
-The system function allows the user to execute operating system commands
-and then return to the @code{awk} program.  The @code{system} function
-executes the command given by the string @var{command}.  It returns, as
-its value, the status returned by the command that was executed.
-
-For example, if the following fragment of code is put in your @code{awk}
-program:
-
-@smallexample
-END @{
-     system("mail -s 'awk run done' operator < /dev/null")
-@}
-@end smallexample
-
-@noindent
-the system operator will be sent mail when the @code{awk} program
-finishes processing input and begins its end-of-input processing.
-
-Note that much the same result can be obtained by redirecting
-@code{print} or @code{printf} into a pipe.  However, if your @code{awk}
-program is interactive, @code{system} is useful for cranking up large
-self-contained programs, such as a shell or an editor.@refill
-
-Some operating systems cannot implement the @code{system} function.
-@code{system} causes a fatal error if it is not supported.
-@end table
-
-@c fakenode --- for prepinfo
-@subheading Controlling Output Buffering with @code{system}
-@cindex flushing buffers
-@cindex buffers, flushing
-@cindex buffering output
-@cindex output, buffering
-
-Many utility programs will @dfn{buffer} their output; they save information
-to be written to a disk file or terminal in memory, until there is enough
-to be written in one operation.  This is often more efficient than writing
-every little bit of information as soon as it is ready.  However, sometimes
-it is necessary to force a program to @dfn{flush} its buffers; that is,
-write the information to its destination, even if a buffer is not full.
-You can do this from your @code{awk} program by calling @code{system}
-with a null string as its argument:
-
-@example
-system("")   # flush output
-@end example
-
-@noindent
-@code{gawk} treats this use of the @code{system} function as a special
-case, and is smart enough not to run a shell (or other command
-interpreter) with the empty command.  Therefore, with @code{gawk}, this
-idiom is not only useful, it is efficient.  While this idiom should work
-with other @code{awk} implementations, it will not necessarily avoid
-starting an unnecessary shell.
-@ignore
-Need a better explanation, perhaps in a separate paragraph.  Explain that
-for
-
-awk 'BEGIN { print "hi"
-             system("echo hello")
-             print "howdy" }'
-
-that the output had better be
-
-             hi
-             hello
-             howdy
-
-and not
-
-             hello
-             hi
-             howdy
-
-which it would be if awk did not flush its buffers before calling system.
-@end ignore
-
-@node Time Functions,  , I/O Functions, Built-in
-@section Functions for Dealing with Time Stamps
-
-@cindex time stamps
-@cindex time of day
-A common use for @code{awk} programs is the processing of log files.
-Log files often contain time stamp information, indicating when a
-particular log record was written.  Many programs log their time stamp
-in the form returned by the @code{time} system call, which is the
-number of seconds since a particular epoch.  On @sc{posix} systems,
-it is the number of seconds since Midnight, January 1, 1970, @sc{utc}.
-
-In order to make it easier to process such log files, and to easily produce
-useful reports, @code{gawk} provides two functions for working with time
-stamps.  Both of these are @code{gawk} extensions; they are not specified
-in the @sc{posix} standard, nor are they in any other known version
-of @code{awk}.
-
-@table @code
-@item systime()
-@findex systime
-This function returns the current time as the number of seconds since
-the system epoch.  On @sc{posix} systems, this is the number of seconds
-since Midnight, January 1, 1970, @sc{utc}.  It may be a different number on
-other systems.
-
-@item strftime(@var{format}, @var{timestamp})
-@findex strftime
-This function returns a string.  It is similar to the function of the
-same name in the @sc{ansi} C standard library.  The time specified by
-@var{timestamp} is used to produce a string, based on the contents
-of the @var{format} string.
-@end table
-
-The @code{systime} function allows you to compare a time stamp from a
-log file with the current time of day.  In particular, it is easy to
-determine how long ago a particular record was logged.  It also allows
-you to produce log records using the ``seconds since the epoch'' format.
-
-The @code{strftime} function allows you to easily turn a time stamp
-into human-readable information.  It is similar in nature to the @code{sprintf}
-function, copying non-format specification characters verbatim to the
-returned string, and substituting date and time values for format
-specifications in the @var{format} string.  If no @var{timestamp} argument
-is supplied, @code{gawk} will use the current time of day as the
-time stamp.@refill
-
-@code{strftime} is guaranteed by the @sc{ansi} C standard to support
-the following date format specifications:
-
-@table @code
-@item %a
-The locale's abbreviated weekday name.
-
-@item %A
-The locale's full weekday name.
-
-@item %b
-The locale's abbreviated month name.
-
-@item %B
-The locale's full month name.
-
-@item %c
-The locale's ``appropriate'' date and time representation.
-
-@item %d
-The day of the month as a decimal number (01--31).
-
-@item %H
-The hour (24-hour clock) as a decimal number (00--23).
-
-@item %I
-The hour (12-hour clock) as a decimal number (01--12).
-
-@item %j
-The day of the year as a decimal number (001--366).
-
-@item %m
-The month as a decimal number (01--12).
-
-@item %M
-The minute as a decimal number (00--59).
-
-@item %p
-The locale's equivalent of the AM/PM designations associated
-with a 12-hour clock.
-
-@item %S
-The second as a decimal number (00--61).  (Occasionally there are
-minutes in a year with one or two leap seconds, which is why the
-seconds can go from 0 all the way to 61.)
-
-@item %U
-The week number of the year (the first Sunday as the first day of week 1)
-as a decimal number (00--53).
-
-@item %w
-The weekday as a decimal number (0--6).  Sunday is day 0.
-
-@item %W
-The week number of the year (the first Monday as the first day of week 1)
-as a decimal number (00--53).
-
-@item %x
-The locale's ``appropriate'' date representation.
-
-@item %X
-The locale's ``appropriate'' time representation.
-
-@item %y
-The year without century as a decimal number (00--99).
-
-@item %Y
-The year with century as a decimal number.
-
-@item %Z
-The time zone name or abbreviation, or no characters if
-no time zone is determinable.
-
-@item %%
-A literal @samp{%}.
-@end table
-
-@c The parenthetical remark here should really be a footnote, but
-@c it gave formatting problems at the FSF. So for now put it in
-@c parentheses.
-If a conversion specifier is not one of the above, the behavior is
-undefined.  (This is because the @sc{ansi} standard for C leaves the
-behavior of the C version of @code{strftime} undefined, and @code{gawk}
-will use the system's version of @code{strftime} if it's there.
-Typically, the conversion specifier will either not appear in the
-returned string, or it will appear literally.)
-
-Informally, a @dfn{locale} is the geographic place in which a program
-is meant to run.  For example, a common way to abbreviate the date
-September 4, 1991 in the United States would be ``9/4/91''.
-In many countries in Europe, however, it would be abbreviated ``4.9.91''.
-Thus, the @samp{%x} specification in a @code{"US"} locale might produce
-@samp{9/4/91}, while in a @code{"EUROPE"} locale, it might produce
-@samp{4.9.91}.  The @sc{ansi} C standard defines a default @code{"C"}
-locale, which is an environment that is typical of what most C programmers
-are used to.
-
-A public-domain C version of @code{strftime} is shipped with @code{gawk}
-for systems that are not yet fully @sc{ansi}-compliant.  If that version is
-used to compile @code{gawk} (@pxref{Installation, ,Installing @code{gawk}}),
-then the following additional format specifications are available:@refill
-
-@table @code
-@item %D
-Equivalent to specifying @samp{%m/%d/%y}.
-
-@item %e
-The day of the month, padded with a blank if it is only one digit.
-
-@item %h
-Equivalent to @samp{%b}, above.
-
-@item %n
-A newline character (ASCII LF).
-
-@item %r
-Equivalent to specifying @samp{%I:%M:%S %p}.
-
-@item %R
-Equivalent to specifying @samp{%H:%M}.
-
-@item %T
-Equivalent to specifying @samp{%H:%M:%S}.
-
-@item %t
-A TAB character.
-
-@item %k
-is replaced by the hour (24-hour clock) as a decimal number (0-23).
-Single digit numbers are padded with a blank.
-
-@item %l
-is replaced by the hour (12-hour clock) as a decimal number (1-12).
-Single digit numbers are padded with a blank.
-
-@item %C
-The century, as a number between 00 and 99.
-
-@item %u
-is replaced by the weekday as a decimal number
-[1 (Monday)--7].
-
-@item %V
-is replaced by the week number of the year (the first Monday as the first
-day of week 1) as a decimal number (01--53).
-The method for determining the week number is as specified by ISO 8601
-(to wit: if the week containing January 1 has four or more days in the
-new year, then it is week 1, otherwise it is week 53 of the previous year
-and the next week is week 1).@refill
-
-@item %Ec %EC %Ex %Ey %EY %Od %Oe %OH %OI
-@itemx %Om %OM %OS %Ou %OU %OV %Ow %OW %Oy
-These are ``alternate representations'' for the specifications
-that use only the second letter (@samp{%c}, @samp{%C}, and so on).
-They are recognized, but their normal representations are used.
-(These facilitate compliance with the @sc{posix} @code{date}
-utility.)@refill
-
-@item %v
-The date in VMS format (e.g. 20-JUN-1991).
-@end table
-
-Here are two examples that use @code{strftime}.  The first is an
-@code{awk} version of the C @code{ctime} function.  (This is a
-user defined function, which we have not discussed yet.
-@xref{User-defined, ,User-defined Functions}, for more information.)
-
-@smallexample
-# ctime.awk
-#
-# awk version of C ctime(3) function
-
-function ctime(ts,    format)
-@{
-    format = "%a %b %e %H:%M:%S %Z %Y"
-    if (ts == 0)
-        ts = systime()         # use current time as default
-    return strftime(format, ts)
-@}
-@end smallexample
-
-This next example is an @code{awk} implementation of the @sc{posix}
-@code{date} utility.  Normally, the @code{date} utility prints the
-current date and time of day in a well known format.  However, if you
-provide an argument to it that begins with a @samp{+}, @code{date}
-will copy non-format specifier characters to the standard output, and
-will interpret the current time according to the format specifiers in
-the string.  For example:
-
-@smallexample
-date '+Today is %A, %B %d, %Y.'
-@end smallexample
-
-@noindent
-might print
-
-@smallexample
-Today is Thursday, July 11, 1991.
-@end smallexample
-
-Here is the @code{awk} version of the @code{date} utility.
-
-@smallexample
-#! /usr/bin/gawk -f
-#
-# date --- implement the P1003.2 Draft 11 'date' command
-#
-# Bug: does not recognize the -u argument.
-
-BEGIN    \
-@{
-    format = "%a %b %e %H:%M:%S %Z %Y"
-    exitval = 0
-
-    if (ARGC > 2)
-        exitval = 1
-    else if (ARGC == 2) @{
-        format = ARGV[1]
-        if (format ~ /^\+/)
-            format = substr(format, 2)    # remove leading +
-    @}
-    print strftime(format)
-    exit exitval
-@}
-@end smallexample
-
-@node User-defined, Built-in Variables, Built-in, Top
-@chapter User-defined Functions
-
-@cindex user-defined functions
-@cindex functions, user-defined
-Complicated @code{awk} programs can often be simplified by defining
-your own functions.  User-defined functions can be called just like
-built-in ones (@pxref{Function Calls}), but it is up to you to define
-them---to tell @code{awk} what they should do.
-
-@menu
-* Definition Syntax::           How to write definitions and what they mean.
-* Function Example::            An example function definition and 
-                                what it does.
-* Function Caveats::            Things to watch out for.
-* Return Statement::            Specifying the value a function returns.
-@end menu
-
-@node Definition Syntax, Function Example, User-defined, User-defined
-@section Syntax of Function Definitions
-@cindex defining functions
-@cindex function definition
-
-Definitions of functions can appear anywhere between the rules of the
-@code{awk} program.  Thus, the general form of an @code{awk} program is
-extended to include sequences of rules @emph{and} user-defined function
-definitions.
-
-The definition of a function named @var{name} looks like this:
-
-@example
-function @var{name} (@var{parameter-list}) @{
-     @var{body-of-function}
-@}
-@end example
-
-@noindent
-@var{name} is the name of the function to be defined.  A valid function
-name is like a valid variable name: a sequence of letters, digits and
-underscores, not starting with a digit.  Functions share the same pool
-of names as variables and arrays.
-
-@var{parameter-list} is a list of the function's arguments and local
-variable names, separated by commas.  When the function is called,
-the argument names are used to hold the argument values given in
-the call.  The local variables are initialized to the null string.
-
-The @var{body-of-function} consists of @code{awk} statements.  It is the
-most important part of the definition, because it says what the function
-should actually @emph{do}.  The argument names exist to give the body a
-way to talk about the arguments; local variables, to give the body
-places to keep temporary values.
-
-Argument names are not distinguished syntactically from local variable
-names; instead, the number of arguments supplied when the function is
-called determines how many argument variables there are.  Thus, if three
-argument values are given, the first three names in @var{parameter-list}
-are arguments, and the rest are local variables.
-
-It follows that if the number of arguments is not the same in all calls
-to the function, some of the names in @var{parameter-list} may be
-arguments on some occasions and local variables on others.  Another
-way to think of this is that omitted arguments default to the
-null string.
-
-Usually when you write a function you know how many names you intend to
-use for arguments and how many you intend to use as locals.  By
-convention, you should write an extra space between the arguments and
-the locals, so other people can follow how your function is
-supposed to be used.
-
-During execution of the function body, the arguments and local variable
-values hide or @dfn{shadow} any variables of the same names used in the
-rest of the program.  The shadowed variables are not accessible in the
-function definition, because there is no way to name them while their
-names have been taken away for the local variables.  All other variables
-used in the @code{awk} program can be referenced or set normally in the
-function definition.
-
-The arguments and local variables last only as long as the function body
-is executing.  Once the body finishes, the shadowed variables come back.
-
-The function body can contain expressions which call functions.  They
-can even call this function, either directly or by way of another
-function.  When this happens, we say the function is @dfn{recursive}.
-
-There is no need in @code{awk} to put the definition of a function
-before all uses of the function.  This is because @code{awk} reads the
-entire program before starting to execute any of it.
-
-In many @code{awk} implementations, the keyword @code{function} may be
-abbreviated @code{func}.  However, @sc{posix} only specifies the use of
-the keyword @code{function}.  This actually has some practical implications.
-If @code{gawk} is in @sc{posix}-compatibility mode
-(@pxref{Command Line, ,Invoking @code{awk}}), then the following
-statement will @emph{not} define a function:@refill
-
-@example
-func foo() @{ a = sqrt($1) ; print a @}
-@end example
-
-@noindent
-Instead it defines a rule that, for each record, concatenates the value
-of the variable @samp{func} with the return value of the function @samp{foo},
-and based on the truth value of the result, executes the corresponding action.
-This is probably not what was desired.  (@code{awk} accepts this input as
-syntactically valid, since functions may be used before they are defined
-in @code{awk} programs.)
-
-@node Function Example, Function Caveats, Definition Syntax, User-defined
-@section Function Definition Example
-
-Here is an example of a user-defined function, called @code{myprint}, that
-takes a number and prints it in a specific format.
-
-@example
-function myprint(num)
-@{
-     printf "%6.3g\n", num
-@}
-@end example
-
-@noindent
-To illustrate, here is an @code{awk} rule which uses our @code{myprint}
-function:
-
-@example
-$3 > 0     @{ myprint($3) @}
-@end example
-
-@noindent
-This program prints, in our special format, all the third fields that
-contain a positive number in our input.  Therefore, when given:
-
-@example
- 1.2   3.4    5.6   7.8
- 9.10 11.12 -13.14 15.16
-17.18 19.20  21.22 23.24
-@end example
-
-@noindent
-this program, using our function to format the results, prints:
-
-@example
-   5.6
-  21.2
-@end example
-
-Here is a rather contrived example of a recursive function.  It prints a
-string backwards:
-
-@example
-function rev (str, len) @{
-    if (len == 0) @{
-        printf "\n"
-        return
-    @}
-    printf "%c", substr(str, len, 1)
-    rev(str, len - 1)
-@}
-@end example
-
-@node Function Caveats, Return Statement, Function Example, User-defined
-@section Calling User-defined Functions
-
-@dfn{Calling a function} means causing the function to run and do its job.
-A function call is an expression, and its value is the value returned by
-the function.
-
-A function call consists of the function name followed by the arguments
-in parentheses.  What you write in the call for the arguments are
-@code{awk} expressions; each time the call is executed, these
-expressions are evaluated, and the values are the actual arguments.  For
-example, here is a call to @code{foo} with three arguments (the first
-being a string concatenation):
-
-@example
-foo(x y, "lose", 4 * z)
-@end example
-
-@quotation
-@strong{Caution:} whitespace characters (spaces and tabs) are not allowed
-between the function name and the open-parenthesis of the argument list.
-If you write whitespace by mistake, @code{awk} might think that you mean
-to concatenate a variable with an expression in parentheses.  However, it
-notices that you used a function name and not a variable name, and reports
-an error.
-@end quotation
-
-@cindex call by value
-When a function is called, it is given a @emph{copy} of the values of
-its arguments.  This is called @dfn{call by value}.  The caller may use
-a variable as the expression for the argument, but the called function
-does not know this: it only knows what value the argument had.  For
-example, if you write this code:
-
-@example
-foo = "bar"
-z = myfunc(foo)
-@end example
-
-@noindent
-then you should not think of the argument to @code{myfunc} as being
-``the variable @code{foo}.''  Instead, think of the argument as the
-string value, @code{"bar"}.
-
-If the function @code{myfunc} alters the values of its local variables,
-this has no effect on any other variables.  In particular, if @code{myfunc}
-does this:
-
-@example
-function myfunc (win) @{
-  print win
-  win = "zzz"
-  print win
-@}
-@end example
-
-@noindent
-to change its first argument variable @code{win}, this @emph{does not}
-change the value of @code{foo} in the caller.  The role of @code{foo} in
-calling @code{myfunc} ended when its value, @code{"bar"}, was computed.
-If @code{win} also exists outside of @code{myfunc}, the function body
-cannot alter this outer value, because it is shadowed during the
-execution of @code{myfunc} and cannot be seen or changed from there.
-
-@cindex call by reference
-However, when arrays are the parameters to functions, they are @emph{not}
-copied.  Instead, the array itself is made available for direct manipulation
-by the function.  This is usually called @dfn{call by reference}.
-Changes made to an array parameter inside the body of a function @emph{are}
-visible outside that function.  
-@ifinfo
-This can be @strong{very} dangerous if you do not watch what you are
-doing.  For example:@refill
-@end ifinfo
-@iftex
-@emph{This can be very dangerous if you do not watch what you are
-doing.}  For example:@refill
-@end iftex
-
-@example
-function changeit (array, ind, nvalue) @{
-     array[ind] = nvalue
-@}
-
-BEGIN @{
-           a[1] = 1 ; a[2] = 2 ; a[3] = 3
-           changeit(a, 2, "two")
-           printf "a[1] = %s, a[2] = %s, a[3] = %s\n", a[1], a[2], a[3]
-      @}
-@end example
-
-@noindent
-prints @samp{a[1] = 1, a[2] = two, a[3] = 3}, because calling
-@code{changeit} stores @code{"two"} in the second element of @code{a}.
-
-@node Return Statement,  , Function Caveats, User-defined
-@section The @code{return} Statement
-@cindex @code{return} statement
-
-The body of a user-defined function can contain a @code{return} statement.
-This statement returns control to the rest of the @code{awk} program.  It
-can also be used to return a value for use in the rest of the @code{awk}
-program.  It looks like this:@refill
-
-@example
-return @var{expression}
-@end example
-
-The @var{expression} part is optional.  If it is omitted, then the returned
-value is undefined and, therefore, unpredictable.
-
-A @code{return} statement with no value expression is assumed at the end of
-every function definition.  So if control reaches the end of the function
-body, then the function returns an unpredictable value.  @code{awk}
-will not warn you if you use the return value of such a function; you will
-simply get unpredictable or unexpected results.
-
-Here is an example of a user-defined function that returns a value
-for the largest number among the elements of an array:@refill
-
-@example
-@group
-function maxelt (vec,   i, ret) @{
-     for (i in vec) @{
-          if (ret == "" || vec[i] > ret)
-               ret = vec[i]
-     @}
-     return ret
-@}
-@end group
-@end example
-
-@noindent
-You call @code{maxelt} with one argument, which is an array name.  The local
-variables @code{i} and @code{ret} are not intended to be arguments;
-while there is nothing to stop you from passing two or three arguments
-to @code{maxelt}, the results would be strange.  The extra space before
-@code{i} in the function parameter list is to indicate that @code{i} and
-@code{ret} are not supposed to be arguments.  This is a convention which
-you should follow when you define functions.
-
-Here is a program that uses our @code{maxelt} function.  It loads an
-array, calls @code{maxelt}, and then reports the maximum number in that
-array:@refill
-
-@example
-@group
-awk '
-function maxelt (vec,   i, ret) @{
-     for (i in vec) @{
-          if (ret == "" || vec[i] > ret)
-               ret = vec[i]
-     @}
-     return ret
-@}
-@end group
-
-@group
-# Load all fields of each record into nums.
-@{
-          for(i = 1; i <= NF; i++)
-               nums[NR, i] = $i
-@}
-
-END @{
-     print maxelt(nums)
-@}'
-@end group
-@end example
-
-Given the following input:
-
-@example
-@group
- 1 5 23 8 16
-44 3 5 2 8 26
-256 291 1396 2962 100
--6 467 998 1101
-99385 11 0 225
-@end group
-@end example
-
-@noindent
-our program tells us (predictably) that:
-
-@example
-99385
-@end example
-
-@noindent
-is the largest number in our array.
-
-@node Built-in Variables, Command Line, User-defined, Top
-@chapter Built-in Variables
-@cindex built-in variables
-
-Most @code{awk} variables are available for you to use for your own
-purposes; they never change except when your program assigns values to
-them, and never affect anything except when your program examines them.
-
-A few variables have special built-in meanings.  Some of them @code{awk}
-examines automatically, so that they enable you to tell @code{awk} how
-to do certain things.  Others are set automatically by @code{awk}, so
-that they carry information from the internal workings of @code{awk} to
-your program.
-
-This chapter documents all the built-in variables of @code{gawk}.  Most
-of them are also documented in the chapters where their areas of
-activity are described.
-
-@menu
-* User-modified::               Built-in variables that you change 
-                                to control @code{awk}.
-* Auto-set::                    Built-in variables where @code{awk} 
-                                gives you information.
-@end menu
-
-@node User-modified, Auto-set, Built-in Variables, Built-in Variables
-@section Built-in Variables that Control @code{awk}
-@cindex built-in variables, user modifiable
-
-This is a list of the variables which you can change to control how
-@code{awk} does certain things.
-
-@table @code
-@iftex
-@vindex CONVFMT
-@end iftex
-@item CONVFMT
-This string is used by @code{awk} to control conversion of numbers to
-strings (@pxref{Conversion, ,Conversion of Strings and Numbers}).
-It works by being passed, in effect, as the first argument to the
-@code{sprintf} function.  Its default value is @code{"%.6g"}.
-@code{CONVFMT} was introduced by the @sc{posix} standard.@refill
-
-@iftex
-@vindex FIELDWIDTHS
-@end iftex
-@item FIELDWIDTHS
-This is a space separated list of columns that tells @code{gawk}
-how to manage input with fixed, columnar boundaries.  It is an
-experimental feature that is still evolving.  Assigning to @code{FIELDWIDTHS}
-overrides the use of @code{FS} for field splitting.
-@xref{Constant Size, ,Reading Fixed-width Data}, for more information.@refill
-
-If @code{gawk} is in compatibility mode
-(@pxref{Command Line, ,Invoking @code{awk}}), then @code{FIELDWIDTHS}
-has no special meaning, and field splitting operations are done based
-exclusively on the value of @code{FS}.@refill
-
-@iftex
-@vindex FS
-@end iftex
-@item FS
-@code{FS} is the input field separator
-(@pxref{Field Separators, ,Specifying how Fields are Separated}).
-The value is a single-character string or a multi-character regular
-expression that matches the separations between fields in an input
-record.@refill
-
-The default value is @w{@code{" "}}, a string consisting of a single
-space.  As a special exception, this value actually means that any
-sequence of spaces and tabs is a single separator.  It also causes
-spaces and tabs at the beginning or end of a line to be ignored.
-
-You can set the value of @code{FS} on the command line using the
-@samp{-F} option:
-
-@example
-awk -F, '@var{program}' @var{input-files}
-@end example
-
-If @code{gawk} is using @code{FIELDWIDTHS} for field-splitting,
-assigning a value to @code{FS} will cause @code{gawk} to return to
-the normal, regexp-based, field splitting.
-
-@item IGNORECASE
-@iftex
-@vindex IGNORECASE
-@end iftex
-If @code{IGNORECASE} is nonzero, then @emph{all} regular expression
-matching is done in a case-independent fashion.  In particular, regexp
-matching with @samp{~} and @samp{!~}, and the @code{gsub} @code{index},
-@code{match}, @code{split} and @code{sub} functions all ignore case when
-doing their particular regexp operations.  @strong{Note:} since field
-splitting with the value of the @code{FS} variable is also a regular
-expression operation, that too is done with case ignored.
-@xref{Case-sensitivity, ,Case-sensitivity in Matching}.
-
-If @code{gawk} is in compatibility mode
-(@pxref{Command Line, ,Invoking @code{awk}}), then @code{IGNORECASE} has
-no special meaning, and regexp operations are always case-sensitive.@refill
-
-@item OFMT
-@iftex
-@vindex OFMT
-@end iftex
-This string is used by @code{awk} to control conversion of numbers to
-strings (@pxref{Conversion, ,Conversion of Strings and Numbers}) for
-printing with the @code{print} statement.
-It works by being passed, in effect, as the first argument to the
-@code{sprintf} function.  Its default value is @code{"%.6g"}.
-Earlier versions of @code{awk} also used @code{OFMT} to specify the
-format for converting numbers to strings in general expressions; this
-has been taken over by @code{CONVFMT}.@refill
-
-@item OFS
-@iftex
-@vindex OFS
-@end iftex
-This is the output field separator (@pxref{Output Separators}).  It is
-output between the fields output by a @code{print} statement.  Its
-default value is @w{@code{" "}}, a string consisting of a single space.
-
-@item ORS
-@iftex
-@vindex ORS
-@end iftex
-This is the output record separator.  It is output at the end of every
-@code{print} statement.  Its default value is a string containing a
-single newline character, which could be written as @code{"\n"}.
-(@xref{Output Separators}.)@refill
-
-@item RS
-@iftex
-@vindex RS
-@end iftex
-This is @code{awk}'s input record separator.  Its default value is a string
-containing a single newline character, which means that an input record
-consists of a single line of text.
-(@xref{Records, ,How Input is Split into Records}.)@refill
-
-@item SUBSEP
-@iftex
-@vindex SUBSEP
-@end iftex
-@code{SUBSEP} is the subscript separator.  It has the default value of
-@code{"\034"}, and is used to separate the parts of the name of a
-multi-dimensional array.  Thus, if you access @code{foo[12,3]}, it
-really accesses @code{foo["12\0343"]}
-(@pxref{Multi-dimensional, ,Multi-dimensional Arrays}).@refill
-@end table
-
-@node Auto-set,  , User-modified, Built-in Variables
-@section Built-in Variables that Convey Information
-
-This is a list of the variables that are set automatically by @code{awk}
-on certain occasions so as to provide information to your program.
-
-@table @code
-@item ARGC
-@itemx ARGV
-@iftex
-@vindex ARGC
-@vindex ARGV
-@end iftex
-The command-line arguments available to @code{awk} programs are stored in
-an array called @code{ARGV}.  @code{ARGC} is the number of command-line
-arguments present.  @xref{Command Line, ,Invoking @code{awk}}.
-@code{ARGV} is indexed from zero to @w{@code{ARGC - 1}}.  For example:@refill
-
-@example
-awk 'BEGIN @{
-       for (i = 0; i < ARGC; i++) 
-           print ARGV[i] 
-     @}' inventory-shipped BBS-list
-@end example
-
-@noindent
-In this example, @code{ARGV[0]} contains @code{"awk"}, @code{ARGV[1]}
-contains @code{"inventory-shipped"}, and @code{ARGV[2]} contains
-@code{"BBS-list"}.  The value of @code{ARGC} is 3, one more than the
-index of the last element in @code{ARGV} since the elements are numbered
-from zero.@refill
-
-The names @code{ARGC} and @code{ARGV}, as well the convention of indexing
-the array from 0 to @w{@code{ARGC - 1}}, are derived from the C language's
-method of accessing command line arguments.@refill
-
-Notice that the @code{awk} program is not entered in @code{ARGV}.  The
-other special command line options, with their arguments, are also not
-entered.  But variable assignments on the command line @emph{are}
-treated as arguments, and do show up in the @code{ARGV} array.
-
-Your program can alter @code{ARGC} and the elements of @code{ARGV}.
-Each time @code{awk} reaches the end of an input file, it uses the next
-element of @code{ARGV} as the name of the next input file.  By storing a
-different string there, your program can change which files are read.
-You can use @code{"-"} to represent the standard input.  By storing
-additional elements and incrementing @code{ARGC} you can cause
-additional files to be read.
-
-If you decrease the value of @code{ARGC}, that eliminates input files
-from the end of the list.  By recording the old value of @code{ARGC}
-elsewhere, your program can treat the eliminated arguments as
-something other than file names.
-
-To eliminate a file from the middle of the list, store the null string
-(@code{""}) into @code{ARGV} in place of the file's name.  As a
-special feature, @code{awk} ignores file names that have been
-replaced with the null string.
-
-@ignore
-see getopt.awk in the examples...
-@end ignore
-
-@item ARGIND
-@vindex ARGIND
-The index in @code{ARGV} of the current file being processed.
-Every time @code{gawk} opens a new data file for processing, it sets
-@code{ARGIND} to the index in @code{ARGV} of the file name.  Thus, the
-condition @samp{FILENAME == ARGV[ARGIND]} is always true.
-
-This variable is useful in file processing; it allows you to tell how far
-along you are in the list of data files, and to distinguish between
-multiple successive instances of the same filename on the command line.
-
-While you can change the value of @code{ARGIND} within your @code{awk}
-program, @code{gawk} will automatically set it to a new value when the
-next file is opened.
-
-This variable is a @code{gawk} extension; in other @code{awk} implementations
-it is not special.
-
-@item ENVIRON
-@vindex ENVIRON
-This is an array that contains the values of the environment.  The array
-indices are the environment variable names; the values are the values of
-the particular environment variables.  For example,
-@code{ENVIRON["HOME"]} might be @file{/u/close}.  Changing this array
-does not affect the environment passed on to any programs that
-@code{awk} may spawn via redirection or the @code{system} function.
-(In a future version of @code{gawk}, it may do so.)
-
-Some operating systems may not have environment variables.
-On such systems, the array @code{ENVIRON} is empty.
-
-@item ERRNO
-@iftex
-@vindex ERRNO
-@end iftex
-If a system error occurs either doing a redirection for @code{getline},
-during a read for @code{getline}, or during a @code{close} operation,
-then @code{ERRNO} will contain a string describing the error.
-
-This variable is a @code{gawk} extension; in other @code{awk} implementations
-it is not special.
-
-@item FILENAME
-@iftex
-@vindex FILENAME
-@end iftex
-This is the name of the file that @code{awk} is currently reading.
-If @code{awk} is reading from the standard input (in other words,
-there are no files listed on the command line),
-@code{FILENAME} is set to @code{"-"}.
-@code{FILENAME} is changed each time a new file is read
-(@pxref{Reading Files, ,Reading Input Files}).@refill
-
-@item FNR
-@iftex
-@vindex FNR
-@end iftex
-@code{FNR} is the current record number in the current file.  @code{FNR} is
-incremented each time a new record is read
-(@pxref{Getline, ,Explicit Input with @code{getline}}).  It is reinitialized
-to 0 each time a new input file is started.@refill
-
-@item NF
-@iftex
-@vindex NF
-@end iftex
-@code{NF} is the number of fields in the current input record.
-@code{NF} is set each time a new record is read, when a new field is
-created, or when @code{$0} changes (@pxref{Fields, ,Examining Fields}).@refill
-
-@item NR
-@iftex
-@vindex NR
-@end iftex
-This is the number of input records @code{awk} has processed since
-the beginning of the program's execution.
-(@pxref{Records, ,How Input is Split into Records}).
-@code{NR} is set each time a new record is read.@refill
-
-@item RLENGTH
-@iftex
-@vindex RLENGTH
-@end iftex
-@code{RLENGTH} is the length of the substring matched by the
-@code{match} function
-(@pxref{String Functions, ,Built-in Functions for String Manipulation}).
-@code{RLENGTH} is set by invoking the @code{match} function.  Its value
-is the length of the matched string, or @minus{}1 if no match was found.@refill
-
-@item RSTART
-@iftex
-@vindex RSTART
-@end iftex
-@code{RSTART} is the start-index in characters of the substring matched by the
-@code{match} function
-(@pxref{String Functions, ,Built-in Functions for String Manipulation}).
-@code{RSTART} is set by invoking the @code{match} function.  Its value
-is the position of the string where the matched substring starts, or 0
-if no match was found.@refill
-@end table
-
-@node Command Line, Language History, Built-in Variables, Top
-@c node-name, next, previous, up
-@chapter Invoking @code{awk}
-@cindex command line
-@cindex invocation of @code{gawk}
-@cindex arguments, command line
-@cindex options, command line
-@cindex long options
-@cindex options, long
-
-There are two ways to run @code{awk}: with an explicit program, or with
-one or more program files.  Here are templates for both of them; items
-enclosed in @samp{@r{[}@dots{}@r{]}} in these templates are optional.
-
-Besides traditional one-letter @sc{posix}-style options, @code{gawk} also
-supports GNU long named options.
-
-@example
-awk @r{[@var{POSIX or GNU style options}]} -f progfile @r{[@code{--}]} @var{file} @dots{}
-awk @r{[@var{POSIX or GNU style options}]} @r{[@code{--}]} '@var{program}' @var{file} @dots{}
-@end example
-
-@menu
-* Options::                     Command line options and their meanings.
-* Other Arguments::             Input file names and variable assignments.
-* AWKPATH Variable::            Searching directories for @code{awk} programs.
-* Obsolete::                    Obsolete Options and/or features.
-* Undocumented::                Undocumented Options and Features.
-@end menu
-
-@node Options, Other Arguments, Command Line, Command Line
-@section Command Line Options
-
-Options begin with a minus sign, and consist of a single character.
-GNU style long named options consist of two minus signs and
-a keyword that can be abbreviated if the abbreviation allows the option
-to be uniquely identified.  If the option takes an argument, then the
-keyword is immediately followed by an equals sign (@samp{=}) and the
-argument's value.  For brevity, the discussion below only refers to the
-traditional short options; however the long and short options are
-interchangeable in all contexts.
-
-Each long named option for @code{gawk} has a corresponding
-@sc{posix}-style option.  The options and their meanings are as follows:
-
-@table @code
-@item -F @var{fs}
-@itemx --field-separator=@var{fs}
-@iftex
-@cindex @code{-F} option
-@end iftex
-@cindex @code{--field-separator} option
-Sets the @code{FS} variable to @var{fs}
-(@pxref{Field Separators, ,Specifying how Fields are Separated}).@refill
-
-@item -f @var{source-file}
-@itemx --file=@var{source-file}
-@iftex
-@cindex @code{-f} option
-@end iftex
-@cindex @code{--file} option
-Indicates that the @code{awk} program is to be found in @var{source-file}
-instead of in the first non-option argument.
-
-@item -v @var{var}=@var{val}
-@itemx --assign=@var{var}=@var{val}
-@cindex @samp{-v} option
-@cindex @code{--assign} option
-Sets the variable @var{var} to the value @var{val} @emph{before}
-execution of the program begins.  Such variable values are available
-inside the @code{BEGIN} rule (see below for a fuller explanation).
-
-The @samp{-v} option can only set one variable, but you can use
-it more than once, setting another variable each time, like this:
-@samp{@w{-v foo=1} @w{-v bar=2}}.
-
-@item -W @var{gawk-opt}
-@cindex @samp{-W} option
-Following the @sc{posix} standard, options that are implementation
-specific are supplied as arguments to the @samp{-W} option.  With @code{gawk},
-these arguments may be separated by commas, or quoted and separated by
-whitespace.  Case is ignored when processing these options.  These options
-also have corresponding GNU style long named options.  The following
-@code{gawk}-specific options are available:
-
-@table @code
-@item -W compat
-@itemx --compat
-@cindex @code{--compat} option
-Specifies @dfn{compatibility mode}, in which the GNU extensions in
-@code{gawk} are disabled, so that @code{gawk} behaves just like Unix
-@code{awk}.
-@xref{POSIX/GNU, ,Extensions in @code{gawk} not in POSIX @code{awk}},
-which summarizes the extensions.  Also see
-@ref{Compatibility Mode, ,Downward Compatibility and Debugging}.@refill
-
-@item -W copyleft
-@itemx -W copyright
-@itemx --copyleft
-@itemx --copyright
-@cindex @code{--copyleft} option
-@cindex @code{--copyright} option
-Print the short version of the General Public License.
-This option may disappear in a future version of @code{gawk}.  
-
-@item -W help
-@itemx -W usage
-@itemx --help
-@itemx --usage
-@cindex @code{--help} option
-@cindex @code{--usage} option
-Print a ``usage'' message summarizing the short and long style options
-that @code{gawk} accepts, and then exit.
-
-@item -W lint
-@itemx --lint
-@cindex @code{--lint} option
-Provide warnings about constructs that are dubious or non-portable to
-other @code{awk} implementations.
-Some warnings are issued when @code{gawk} first reads your program.  Others
-are issued at run-time, as your program executes.
-
-@item -W posix
-@itemx --posix
-@cindex @code{--posix} option
-Operate in strict @sc{posix} mode.  This disables all @code{gawk}
-extensions (just like @code{-W compat}), and adds the following additional
-restrictions:
-
-@itemize @bullet{}
-@item
-@code{\x} escape sequences are not recognized
-(@pxref{Constants, ,Constant Expressions}).@refill
-
-@item
-The synonym @code{func} for the keyword @code{function} is not
-recognized (@pxref{Definition Syntax, ,Syntax of Function Definitions}).
-
-@item
-The operators @samp{**} and @samp{**=} cannot be used in
-place of @samp{^} and @samp{^=} (@pxref{Arithmetic Ops, ,Arithmetic Operators},
-and also @pxref{Assignment Ops, ,Assignment Expressions}).@refill
-
-@item
-Specifying @samp{-Ft} on the command line does not set the value
-of @code{FS} to be a single tab character
-(@pxref{Field Separators, ,Specifying how Fields are Separated}).@refill
-@end itemize
-
-Although you can supply both @samp{-W compat} and @samp{-W posix} on the
-command line, @samp{-W posix} will take precedence.
-
-@item -W source=@var{program-text}
-@itemx --source=@var{program-text}
-@cindex @code{--source} option
-Program source code is taken from the @var{program-text}.  This option
-allows you to mix @code{awk} source code in files with program source
-code that you would enter on the command line. This is particularly useful
-when you have library functions that you wish to use from your command line
-programs (@pxref{AWKPATH Variable, ,The @code{AWKPATH} Environment Variable}).
-
-@item -W version
-@itemx --version
-@cindex @code{--version} option
-Prints version information for this particular copy of @code{gawk}.
-This is so you can determine if your copy of @code{gawk} is up to date
-with respect to whatever the Free Software Foundation is currently
-distributing.  This option may disappear in a future version of @code{gawk}.
-@end table
-
-@item --
-Signals the end of the command line options.  The following arguments
-are not treated as options even if they begin with @samp{-}.  This
-interpretation of @samp{--} follows the @sc{posix} argument parsing
-conventions.
-
-This is useful if you have file names that start with @samp{-},
-or in shell scripts, if you have file names that will be specified
-by the user which could start with @samp{-}.
-@end table
-
-Any other options are flagged as invalid with a warning message, but
-are otherwise ignored.
-
-In compatibility mode, as a special case, if the value of @var{fs} supplied
-to the @samp{-F} option is @samp{t}, then @code{FS} is set to the tab
-character (@code{"\t"}).  This is only true for @samp{-W compat}, and not
-for @samp{-W posix}
-(@pxref{Field Separators, ,Specifying how Fields are Separated}).@refill
-
-If the @samp{-f} option is @emph{not} used, then the first non-option
-command line argument is expected to be the program text.
-
-The @samp{-f} option may be used more than once on the command line.
-If it is, @code{awk} reads its program source from all of the named files, as
-if they had been concatenated together into one big file.  This is
-useful for creating libraries of @code{awk} functions.  Useful functions
-can be written once, and then retrieved from a standard place, instead
-of having to be included into each individual program.  You can still
-type in a program at the terminal and use library functions, by specifying
-@samp{-f /dev/tty}.  @code{awk} will read a file from the terminal
-to use as part of the @code{awk} program.  After typing your program,
-type @kbd{Control-d} (the end-of-file character) to terminate it.
-(You may also use @samp{-f -} to read program source from the standard
-input, but then you will not be able to also use the standard input as a
-source of data.)
-
-Because it is clumsy using the standard @code{awk} mechanisms to mix source
-file and command line @code{awk} programs, @code{gawk} provides the
-@samp{--source} option.  This does not require you to pre-empt the standard
-input for your source code, and allows you to easily mix command line
-and library source code
-(@pxref{AWKPATH Variable, ,The @code{AWKPATH} Environment Variable}).
-
-If no @samp{-f} or @samp{--source} option is specified, then @code{gawk}
-will use the first non-option command line argument as the text of the
-program source code.
-
-@node Other Arguments, AWKPATH Variable, Options, Command Line
-@section Other Command Line Arguments
-
-Any additional arguments on the command line are normally treated as
-input files to be processed in the order specified.  However, an
-argument that has the form @code{@var{var}=@var{value}}, means to assign
-the value @var{value} to the variable @var{var}---it does not specify a
-file at all.
-
-@vindex ARGV
-All these arguments are made available to your @code{awk} program in the
-@code{ARGV} array (@pxref{Built-in Variables}).  Command line options
-and the program text (if present) are omitted from the @code{ARGV}
-array.  All other arguments, including variable assignments, are
-included.
-
-The distinction between file name arguments and variable-assignment
-arguments is made when @code{awk} is about to open the next input file.
-At that point in execution, it checks the ``file name'' to see whether
-it is really a variable assignment; if so, @code{awk} sets the variable
-instead of reading a file.
-
-Therefore, the variables actually receive the specified values after all
-previously specified files have been read.  In particular, the values of
-variables assigned in this fashion are @emph{not} available inside a
-@code{BEGIN} rule
-(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}),
-since such rules are run before @code{awk} begins scanning the argument list.
-The values given on the command line are processed for escape sequences
-(@pxref{Constants, ,Constant Expressions}).@refill
-
-In some earlier implementations of @code{awk}, when a variable assignment
-occurred before any file names, the assignment would happen @emph{before}
-the @code{BEGIN} rule was executed.  Some applications came to depend
-upon this ``feature.''  When @code{awk} was changed to be more consistent,
-the @samp{-v} option was added to accommodate applications that depended
-upon this old behavior.
-
-The variable assignment feature is most useful for assigning to variables
-such as @code{RS}, @code{OFS}, and @code{ORS}, which control input and
-output formats, before scanning the data files.  It is also useful for
-controlling state if multiple passes are needed over a data file.  For
-example:@refill
-
-@cindex multiple passes over data
-@cindex passes, multiple
-@smallexample
-awk 'pass == 1  @{ @var{pass 1 stuff} @}
-     pass == 2  @{ @var{pass 2 stuff} @}' pass=1 datafile pass=2 datafile
-@end smallexample
-
-Given the variable assignment feature, the @samp{-F} option is not
-strictly necessary.  It remains for historical compatibility.
-
-@node AWKPATH Variable, Obsolete, Other Arguments, Command Line
-@section The @code{AWKPATH} Environment Variable
-@cindex @code{AWKPATH} environment variable
-@cindex search path
-@cindex directory search
-@cindex path, search
-@iftex
-@cindex differences between @code{gawk} and @code{awk}
-@end iftex
-
-The previous section described how @code{awk} program files can be named
-on the command line with the @samp{-f} option.  In some @code{awk}
-implementations, you must supply a precise path name for each program
-file, unless the file is in the current directory.
-
-But in @code{gawk}, if the file name supplied in the @samp{-f} option
-does not contain a @samp{/}, then @code{gawk} searches a list of
-directories (called the @dfn{search path}), one by one, looking for a
-file with the specified name.
-
-The search path is actually a string consisting of directory names
-separated by colons.  @code{gawk} gets its search path from the
-@code{AWKPATH} environment variable.  If that variable does not exist,
-@code{gawk} uses the default path, which is
-@samp{.:/usr/lib/awk:/usr/local/lib/awk}.  (Programs written by
-system administrators should use an @code{AWKPATH} variable that
-does not include the current directory, @samp{.}.)@refill
-
-The search path feature is particularly useful for building up libraries
-of useful @code{awk} functions.  The library files can be placed in a
-standard directory that is in the default path, and then specified on
-the command line with a short file name.  Otherwise, the full file name
-would have to be typed for each file.
-
-By combining the @samp{--source} and @samp{-f} options, your command line
-@code{awk} programs can use facilities in @code{awk} library files.
-
-Path searching is not done if @code{gawk} is in compatibility mode.
-This is true for both @samp{-W compat} and @samp{-W posix}.
-@xref{Options, ,Command Line Options}.
-
-@strong{Note:} if you want files in the current directory to be found,
-you must include the current directory in the path, either by writing
-@file{.} as an entry in the path, or by writing a null entry in the
-path.  (A null entry is indicated by starting or ending the path with a
-colon, or by placing two colons next to each other (@samp{::}).)  If the
-current directory is not included in the path, then files cannot be
-found in the current directory.  This path search mechanism is identical
-to the shell's.
-@c someday, @cite{The Bourne Again Shell}....
-
-@node Obsolete, Undocumented, AWKPATH Variable, Command Line
-@section Obsolete Options and/or Features
-
-@cindex deprecated options
-@cindex obsolete options
-@cindex deprecated features
-@cindex obsolete features
-This section describes features and/or command line options from the
-previous release of @code{gawk} that are either not available in the
-current version, or that are still supported but deprecated (meaning that
-they will @emph{not} be in the next release).
-
-@c update this section for each release!
-
-For version 2.15 of @code{gawk}, the following command line options
-from version 2.11.1 are no longer recognized.
-
-@table @samp
-@ignore
-@item -nostalgia
-Use @samp{-W nostalgia} instead.
-@end ignore
-
-@item -c
-Use @samp{-W compat} instead.
-
-@item -V
-Use @samp{-W version} instead.
-
-@item -C
-Use @samp{-W copyright} instead.
-
-@item -a
-@itemx -e
-These options produce an ``unrecognized option'' error message but have
-no effect on the execution of @code{gawk}.  The @sc{posix} standard now
-specifies traditional @code{awk} regular expressions for the @code{awk} utility.
-@end table
-
-The public-domain version of @code{strftime} that is distributed with
-@code{gawk} changed for the 2.14 release.  The @samp{%V} conversion specifier
-that used to generate the date in VMS format was changed to @samp{%v}.
-This is because the @sc{posix} standard for the @code{date} utility now
-specifies a @samp{%V} conversion specifier.
-@xref{Time Functions, ,Functions for Dealing with Time Stamps}, for details.
-
-@node Undocumented,  , Obsolete, Command Line
-@section Undocumented Options and Features
-
-This section intentionally left blank.
-
-@c Read The Source, Luke!
-
-@ignore
-@c If these came out in the Info file or TeX manual, then they wouldn't
-@c be undocumented, would they?
-
-@code{gawk} has one undocumented option:
-
-@table @samp
-@item -W nostalgia
-Print the message @code{"awk: bailing out near line 1"} and dump core.
-This option was inspired by the common behavior of very early versions of
-Unix @code{awk}, and by a t--shirt.
-@end table
-
-Early versions of @code{awk} used to not require any separator (either
-a newline or @samp{;}) between the rules in @code{awk} programs.  Thus,
-it was common to see one-line programs like:
-
-@example
-awk '@{ sum += $1 @} END @{ print sum @}'
-@end example
-
-@code{gawk} actually supports this, but it is purposely undocumented
-since it is considered bad style.  The correct way to write such a program
-is either
-
-@example
-awk '@{ sum += $1 @} ; END @{ print sum @}'
-@end example
-
-@noindent
-or
-
-@example
-awk '@{ sum += $1 @}
-     END @{ print sum @}' data
-@end example
-
-@noindent
-@xref{Statements/Lines, ,@code{awk} Statements versus Lines}, for a fuller
-explanation.@refill
-
-As an accident of the implementation of the original Unix @code{awk}, if
-a built-in function used @code{$0} as its default argument, it was possible
-to call that function without the parentheses.  In particular, it was
-common practice to use the @code{length} function in this fashion.
-For example, the pipeline:
-
-@example
-echo abcdef | awk '@{ print length @}'
-@end example
-
-@noindent
-would print @samp{6}.
-
-For backwards compatibility with old programs, @code{gawk} supports
-this usage, but only for the @code{length} function.  New programs should
-@emph{not} call the @code{length} function this way.  In particular,
-this usage will not be portable to other @sc{posix} compliant versions
-of @code{awk}.  It is also poor style.
-
-@end ignore
-
-@node Language History, Installation, Command Line, Top
-@chapter The Evolution of the @code{awk} Language
-
-This manual describes the GNU implementation of @code{awk}, which is patterned
-after the @sc{posix} specification.  Many @code{awk} users are only familiar
-with the original @code{awk} implementation in Version 7 Unix, which is also
-the basis for the version in Berkeley Unix (through 4.3--Reno).  This chapter
-briefly describes the evolution of the @code{awk} language.
-
-@menu
-* V7/S5R3.1::                   The major changes between V7 and 
-                                System V Release 3.1.
-* S5R4::                        Minor changes between System V 
-                                Releases 3.1 and 4.
-* POSIX::                       New features from the @sc{posix} standard.
-* POSIX/GNU::                   The extensions in @code{gawk} 
-                                not in @sc{posix} @code{awk}.
-@end menu
-
-@node V7/S5R3.1, S5R4, Language History, Language History
-@section Major Changes between V7 and S5R3.1
-
-The @code{awk} language evolved considerably between the release of
-Version 7 Unix (1978) and the new version first made widely available in
-System V Release 3.1 (1987).  This section summarizes the changes, with
-cross-references to further details.
-
-@itemize @bullet
-@item
-The requirement for @samp{;} to separate rules on a line
-(@pxref{Statements/Lines, ,@code{awk} Statements versus Lines}).
-
-@item
-User-defined functions, and the @code{return} statement
-(@pxref{User-defined, ,User-defined Functions}).
-
-@item
-The @code{delete} statement (@pxref{Delete, ,The @code{delete} Statement}).
-
-@item
-The @code{do}-@code{while} statement
-(@pxref{Do Statement, ,The @code{do}-@code{while} Statement}).@refill
-
-@item
-The built-in functions @code{atan2}, @code{cos}, @code{sin}, @code{rand} and
-@code{srand} (@pxref{Numeric Functions, ,Numeric Built-in Functions}).
-
-@item
-The built-in functions @code{gsub}, @code{sub}, and @code{match}
-(@pxref{String Functions, ,Built-in Functions for String Manipulation}).
-
-@item
-The built-in functions @code{close}, which closes an open file, and
-@code{system}, which allows the user to execute operating system
-commands (@pxref{I/O Functions, ,Built-in Functions for Input/Output}).@refill
-@c Does the above verbiage prevents an overfull hbox?  --mew, rjc 24jan1992
-
-@item
-The @code{ARGC}, @code{ARGV}, @code{FNR}, @code{RLENGTH}, @code{RSTART},
-and @code{SUBSEP} built-in variables (@pxref{Built-in Variables}).
-
-@item
-The conditional expression using the operators @samp{?} and @samp{:}
-(@pxref{Conditional Exp, ,Conditional Expressions}).@refill
-
-@item
-The exponentiation operator @samp{^}
-(@pxref{Arithmetic Ops, ,Arithmetic Operators}) and its assignment operator
-form @samp{^=} (@pxref{Assignment Ops, ,Assignment Expressions}).@refill
-
-@item
-C-compatible operator precedence, which breaks some old @code{awk}
-programs (@pxref{Precedence, ,Operator Precedence (How Operators Nest)}).
-
-@item
-Regexps as the value of @code{FS}
-(@pxref{Field Separators, ,Specifying how Fields are Separated}), and as the
-third argument to the @code{split} function
-(@pxref{String Functions, ,Built-in Functions for String Manipulation}).@refill
-
-@item
-Dynamic regexps as operands of the @samp{~} and @samp{!~} operators
-(@pxref{Regexp Usage, ,How to Use Regular Expressions}).
-
-@item
-Escape sequences (@pxref{Constants, ,Constant Expressions}) in regexps.@refill
-
-@item
-The escape sequences @samp{\b}, @samp{\f}, and @samp{\r}
-(@pxref{Constants, ,Constant Expressions}).
-
-@item
-Redirection of input for the @code{getline} function
-(@pxref{Getline, ,Explicit Input with @code{getline}}).@refill
-
-@item
-Multiple @code{BEGIN} and @code{END} rules
-(@pxref{BEGIN/END, ,@code{BEGIN} and @code{END} Special Patterns}).@refill
-
-@item
-Simulated multi-dimensional arrays
-(@pxref{Multi-dimensional, ,Multi-dimensional Arrays}).@refill
-@end itemize
-
-@node S5R4, POSIX, V7/S5R3.1, Language History
-@section Changes between S5R3.1 and S5R4
-
-The System V Release 4 version of Unix @code{awk} added these features
-(some of which originated in @code{gawk}):
-
-@itemize @bullet
-@item
-The @code{ENVIRON} variable (@pxref{Built-in Variables}).
-
-@item
-Multiple @samp{-f} options on the command line
-(@pxref{Command Line, ,Invoking @code{awk}}).@refill
-
-@item
-The @samp{-v} option for assigning variables before program execution begins
-(@pxref{Command Line, ,Invoking @code{awk}}).@refill
-
-@item
-The @samp{--} option for terminating command line options.
-
-@item
-The @samp{\a}, @samp{\v}, and @samp{\x} escape sequences
-(@pxref{Constants, ,Constant Expressions}).@refill
-
-@item
-A defined return value for the @code{srand} built-in function
-(@pxref{Numeric Functions, ,Numeric Built-in Functions}).
-
-@item
-The @code{toupper} and @code{tolower} built-in string functions
-for case translation
-(@pxref{String Functions, ,Built-in Functions for String Manipulation}).@refill
-
-@item
-A cleaner specification for the @samp{%c} format-control letter in the
-@code{printf} function
-(@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing}).@refill
-
-@item
-The ability to dynamically pass the field width and precision (@code{"%*.*d"})
-in the argument list of the @code{printf} function
-(@pxref{Printf, ,Using @code{printf} Statements for Fancier Printing}).@refill
-
-@item
-The use of constant regexps such as @code{/foo/} as expressions, where
-they are equivalent to use of the matching operator, as in @code{$0 ~
-/foo/} (@pxref{Constants, ,Constant Expressions}).
-@end itemize
-
-@node POSIX, POSIX/GNU, S5R4, Language History
-@section Changes between S5R4 and POSIX @code{awk}
-
-The @sc{posix} Command Language and Utilities standard for @code{awk}
-introduced the following changes into the language:
-
-@itemize @bullet{}
-@item
-The use of @samp{-W} for implementation-specific options.
-
-@item
-The use of @code{CONVFMT} for controlling the conversion of numbers
-to strings (@pxref{Conversion, ,Conversion of Strings and Numbers}).
-
-@item
-The concept of a numeric string, and tighter comparison rules to go
-with it (@pxref{Comparison Ops, ,Comparison Expressions}).
-
-@item
-More complete documentation of many of the previously undocumented
-features of the language.
-@end itemize
-
-@node POSIX/GNU,  , POSIX, Language History
-@section Extensions in @code{gawk} not in POSIX @code{awk}
-
-The GNU implementation, @code{gawk}, adds these features:
-
-@itemize @bullet
-@item
-The @code{AWKPATH} environment variable for specifying a path search for
-the @samp{-f} command line option
-(@pxref{Command Line, ,Invoking @code{awk}}).@refill
-
-@item
-The various @code{gawk} specific features available via the @samp{-W}
-command line option (@pxref{Command Line, ,Invoking @code{awk}}).
-
-@item
-The @code{ARGIND} variable, that tracks the movement of @code{FILENAME}
-through @code{ARGV}.  (@pxref{Built-in Variables}).
-
-@item
-The @code{ERRNO} variable, that contains the system error message when
-@code{getline} returns @minus{}1, or when @code{close} fails.
-(@pxref{Built-in Variables}).
-
-@item
-The @code{IGNORECASE} variable and its effects
-(@pxref{Case-sensitivity, ,Case-sensitivity in Matching}).@refill
-
-@item
-The @code{FIELDWIDTHS} variable and its effects
-(@pxref{Constant Size, ,Reading Fixed-width Data}).@refill
-
-@item
-The @code{next file} statement for skipping to the next data file
-(@pxref{Next File Statement, ,The @code{next file} Statement}).@refill
-
-@item
-The @code{systime} and @code{strftime} built-in functions for obtaining
-and printing time stamps
-(@pxref{Time Functions, ,Functions for Dealing with Time Stamps}).@refill
-
-@item
-The @file{/dev/stdin}, @file{/dev/stdout}, @file{/dev/stderr}, and
-@file{/dev/fd/@var{n}} file name interpretation
-(@pxref{Special Files, ,Standard I/O Streams}).@refill
-
-@item
-The @samp{-W compat} option to turn off these extensions
-(@pxref{Command Line, ,Invoking @code{awk}}).@refill
-
-@item
-The @samp{-W posix} option for full @sc{posix} compliance
-(@pxref{Command Line, ,Invoking @code{awk}}).@refill
-
-@end itemize
-
-@node Installation, Gawk Summary, Language History, Top
-@chapter Installing @code{gawk}
-
-This chapter provides instructions for installing @code{gawk} on the
-various platforms that are supported by the developers.  The primary
-developers support Unix (and one day, GNU), while the other ports were
-contributed.  The file @file{ACKNOWLEDGMENT} in the @code{gawk}
-distribution lists the electronic mail addresses of the people who did
-the respective ports.@refill
-
-@menu
-* Gawk Distribution::           What is in the @code{gawk} distribution.
-* Unix Installation::           Installing @code{gawk} under various versions
-                                of Unix.
-* VMS Installation::            Installing @code{gawk} on VMS.
-* MS-DOS Installation::         Installing @code{gawk} on MS-DOS.
-* Atari Installation::          Installing @code{gawk} on the Atari ST.
-@end menu
-
-@node Gawk Distribution, Unix Installation, Installation, Installation
-@section The @code{gawk} Distribution
-
-This section first describes how to get and extract the @code{gawk}
-distribution, and then discusses what is in the various files and
-subdirectories.
-
-@menu
-* Extracting::                  How to get and extract the distribution.
-* Distribution contents::       What is in the distribution.
-@end menu
-
-@node Extracting, Distribution contents, Gawk Distribution, Gawk Distribution
-@subsection Getting the @code{gawk} Distribution
-
-@cindex getting gawk
-@cindex anonymous ftp
-@cindex anonymous uucp
-@cindex ftp, anonymous
-@cindex uucp, anonymous
-@code{gawk} is distributed as a @code{tar} file compressed with the
-GNU Zip program, @code{gzip}.  You can
-get it via anonymous @code{ftp} to the Internet host @code{prep.ai.mit.edu}.
-Like all GNU software, it will be archived at other well known systems,
-from which it will be possible to use some sort of anonymous @code{uucp} to
-obtain the distribution as well.
-You can also order @code{gawk} on tape or CD-ROM directly from the
-Free Software Foundation.  (The address is on the copyright page.)
-Doing so directly contributes to the support of the foundation and to
-the production of more free software.
-
-Once you have the distribution (for example,
-@file{gawk-2.15.0.tar.z}), first use @code{gzip} to expand the
-file, and then use @code{tar} to extract it.  You can use the following
-pipeline to produce the @code{gawk} distribution:
-
-@example
-# Under System V, add 'o' to the tar flags
-gzip -d -c gawk-2.15.0.tar.z | tar -xvpf -
-@end example
-
-@noindent
-This will create a directory named @file{gawk-2.15} in the current
-directory.
-
-The distribution file name is of the form @file{gawk-2.15.@var{n}.tar.Z}.
-The @var{n} represents a @dfn{patchlevel}, meaning that minor bugs have
-been fixed in the major release.  The current patchlevel is 0, but when
-retrieving distributions, you should get the version with the highest
-patchlevel.@refill
-
-If you are not on a Unix system, you will need to make other arrangements
-for getting and extracting the @code{gawk} distribution.  You should consult
-a local expert.
-
-@node Distribution contents,  , Extracting, Gawk Distribution
-@subsection Contents of the @code{gawk} Distribution
-
-@code{gawk} has a number of C source files, documentation files,
-subdirectories and files related to the configuration process
-(@pxref{Unix Installation, ,Compiling and Installing @code{gawk} on Unix}),
-and several subdirectories related to different, non-Unix,
-operating systems.@refill
-
-@table @asis
-@item various @samp{.c}, @samp{.y}, and @samp{.h} files 
-
-The C and YACC source files are the actual @code{gawk} source code.
-@end table
-
-@table @file
-@item README
-@itemx README.VMS
-@itemx README.dos
-@itemx README.rs6000
-@itemx README.ultrix
-Descriptive files: @file{README} for @code{gawk} under Unix, and the
-rest for the various hardware and software combinations.
-
-@item PORTS
-A list of systems to which @code{gawk} has been ported, and which
-have successfully run the test suite.
-
-@item ACKNOWLEDGMENT
-A list of the people who contributed major parts of the code or documentation.
-
-@item NEWS
-A list of changes to @code{gawk} since the last release or patch.
-
-@item COPYING
-The GNU General Public License.
-
-@item FUTURES
-A brief list of features and/or changes being contemplated for future
-releases, with some indication of the time frame for the feature, based
-on its difficulty.
-
-@item LIMITATIONS
-A list of those factors that limit @code{gawk}'s performance.
-Most of these depend on the hardware or operating system software, and
-are not limits in @code{gawk} itself.@refill
-
-@item PROBLEMS
-A file describing known problems with the current release.
-
-@item gawk.1
-The @code{troff} source for a manual page describing @code{gawk}.
-
-@item gawk.texinfo
-@ifinfo
-The @code{texinfo} source file for this Info file.
-It should be processed with @TeX{} to produce a printed manual, and
-with @code{makeinfo} to produce the Info file.@refill
-@end ifinfo
-@iftex
-The @code{texinfo} source file for this manual.
-It should be processed with @TeX{} to produce a printed manual, and
-with @code{makeinfo} to produce the Info file.@refill
-@end iftex
-
-@item Makefile.in
-@itemx config
-@itemx config.in
-@itemx configure
-@itemx missing
-@itemx mungeconf
-These files and subdirectories are used when configuring @code{gawk}
-for various Unix systems.  They are explained in detail in
-@ref{Unix Installation, ,Compiling and Installing @code{gawk} on Unix}.@refill
-
-@item atari
-Files needed for building @code{gawk} on an Atari ST.
-@xref{Atari Installation, ,Installing @code{gawk} on the Atari ST}, for details.
-
-@item pc
-Files needed for building @code{gawk} under MS-DOS.
-@xref{MS-DOS Installation, ,Installing @code{gawk} on MS-DOS}, for details.
-
-@item vms
-Files needed for building @code{gawk} under VMS.
-@xref{VMS Installation, ,Compiling Installing and Running @code{gawk} on VMS}, for details.
-
-@item test
-Many interesting @code{awk} programs, provided as a test suite for
-@code{gawk}.  You can use @samp{make test} from the top level @code{gawk}
-directory to run your version of @code{gawk} against the test suite.
-@c There are many programs here that are useful in their own right.
-If @code{gawk} successfully passes @samp{make test} then you can
-be confident of a successful port.@refill
-@end table
-
-@node Unix Installation, VMS Installation, Gawk Distribution, Installation
-@section Compiling and Installing @code{gawk} on Unix
-
-Often, you can compile and install @code{gawk} by typing only two
-commands.  However, if you do not use a supported system, you may need
-to configure @code{gawk} for your system yourself.
-
-@menu
-* Quick Installation::          Compiling @code{gawk} on a 
-                                supported Unix version.
-* Configuration Philosophy::    How it's all supposed to work.
-* New Configurations::          What to do if there is no supplied 
-                                configuration for your system.
-@end menu
-
-@node Quick Installation, Configuration Philosophy, Unix Installation, Unix Installation
-@subsection Compiling @code{gawk} for a Supported Unix Version
-
-@cindex installation, unix
-After you have extracted the @code{gawk} distribution, @code{cd}
-to @file{gawk-2.15}.  Look in the @file{config} subdirectory for a
-file that matches your hardware/software combination.  In general,
-only the software is relevant; for example @code{sunos41} is used
-for SunOS 4.1, on both Sun 3 and Sun 4 hardware.@refill
-
-If you find such a file, run the command:
-
-@example
-# assume you have SunOS 4.1
-./configure sunos41
-@end example
-
-This produces a @file{Makefile} and @file{config.h} tailored to your
-system.  You may wish to edit the @file{Makefile} to use a different
-C compiler, such as @code{gcc}, the GNU C compiler, if you have it.
-You may also wish to change the @code{CFLAGS} variable, which controls
-the command line options that are passed to the C compiler (such as
-optimization levels, or compiling for debugging).@refill
-
-After you have configured @file{Makefile} and @file{config.h}, type:
-
-@example
-make
-@end example
-
-@noindent
-and shortly thereafter, you should have an executable version of @code{gawk}.
-That's all there is to it!
-
-@node Configuration Philosophy, New Configurations, Quick Installation, Unix Installation
-@subsection The Configuration Process
-
-(This section is of interest only if you know something about using the
-C language and the Unix operating system.)
-
-The source code for @code{gawk} generally attempts to adhere to industry
-standards wherever possible.  This means that @code{gawk} uses library
-routines that are specified by the @sc{ansi} C standard and by the @sc{posix}
-operating system interface standard.  When using an @sc{ansi} C compiler,
-function prototypes are provided to help improve the compile-time checking.
-
-Many older Unix systems do not support all of either the @sc{ansi} or the
-@sc{posix} standards.  The @file{missing} subdirectory in the @code{gawk}
-distribution contains replacement versions of those subroutines that are
-most likely to be missing.
-
-The @file{config.h} file that is created by the @code{configure} program
-contains definitions that describe features of the particular operating
-system where you are attempting to compile @code{gawk}.  For the most
-part, it lists which standard subroutines are @emph{not} available.
-For example, if your system lacks the @samp{getopt} routine, then
-@samp{GETOPT_MISSING} would be defined.
-
-@file{config.h} also defines constants that describe facts about your
-variant of Unix.  For example, there may not be an @samp{st_blksize}
-element in the @code{stat} structure.  In this case @samp{BLKSIZE_MISSING}
-would be defined.
-
-Based on the list in @file{config.h} of standard subroutines that are
-missing, @file{missing.c} will do a @samp{#include} of the appropriate
-file(s) from the @file{missing} subdirectory.@refill
-
-Conditionally compiled code in the other source files relies on the
-other definitions in the @file{config.h} file.
-
-Besides creating @file{config.h}, @code{configure} produces a @file{Makefile}
-from @file{Makefile.in}.  There are a number of lines in @file{Makefile.in}
-that are system or feature specific.  For example, there is line that begins
-with @samp{##MAKE_ALLOCA_C##}.  This is normally a comment line, since
-it starts with @samp{#}.  If a configuration file has @samp{MAKE_ALLOCA_C}
-in it, then @code{configure} will delete the @samp{##MAKE_ALLOCA_C##}
-from the beginning of the line.  This will enable the rules in the
-@file{Makefile} that use a C version of @samp{alloca}.  There are several
-similar features that work in this fashion.@refill
-
-@node New Configurations,  , Configuration Philosophy, Unix Installation
-@subsection Configuring @code{gawk} for a New System
-
-(This section is of interest only if you know something about using the
-C language and the Unix operating system, and if you have to install
-@code{gawk} on a system that is not supported by the @code{gawk} distribution.
-If you are a C or Unix novice, get help from a local expert.)
-
-If you need to configure @code{gawk} for a Unix system that is not
-supported in the distribution, first see
-@ref{Configuration Philosophy, ,The Configuration Process}.
-Then, copy @file{config.in} to @file{config.h}, and copy
-@file{Makefile.in} to @file{Makefile}.@refill
-
-Next, edit both files.  Both files are liberally commented, and the
-necessary changes should be straightforward.
-
-While editing @file{config.h}, you need to determine what library
-routines you do or do not have by consulting your system documentation, or
-by perusing your actual libraries using the @code{ar} or @code{nm} utilities.
-In the worst case, simply do not define @emph{any} of the macros for missing
-subroutines.  When you compile @code{gawk}, the final link-editing step
-will fail.  The link editor will provide you with a list of unresolved external
-references---these are the missing subroutines.  Edit @file{config.h} again
-and recompile, and you should be set.@refill
-
-Editing the @file{Makefile} should also be straightforward.  Enable or
-disable the lines that begin with @samp{##MAKE_@var{whatever}##}, as
-appropriate.  Select the correct C compiler and @code{CFLAGS} for it.
-Then run @code{make}.
-
-Getting a correct configuration is likely to be an iterative process.
-Do not be discouraged if it takes you several tries.  If you have no
-luck whatsoever, please report your system type, and the steps you took.
-Once you do have a working configuration, please send it to the maintainers
-so that support for your system can be added to the official release.
-
-@xref{Bugs, ,Reporting Problems and Bugs}, for information on how to report
-problems in configuring @code{gawk}.  You may also use the same mechanisms
-for sending in new configurations.@refill
-
-@node VMS Installation, MS-DOS Installation, Unix Installation, Installation
-@section Compiling, Installing, and Running @code{gawk} on VMS
-
-@c based on material from
-@c Pat Rankin <rankin@eql.caltech.edu>
-
-@cindex installation, vms
-This section describes how to compile and install @code{gawk} under VMS.
-
-@menu
-* VMS Compilation::             How to compile @code{gawk} under VMS.
-* VMS Installation Details::    How to install @code{gawk} under VMS.
-* VMS Running::                 How to run @code{gawk} under VMS.
-* VMS POSIX::                   Alternate instructions for VMS POSIX.
-@end menu
-
-@node VMS Compilation, VMS Installation Details, VMS Installation, VMS Installation
-@subsection Compiling @code{gawk} under VMS
-
-To compile @code{gawk} under VMS, there is a @code{DCL} command procedure that
-will issue all the necessary @code{CC} and @code{LINK} commands, and there is
-also a @file{Makefile} for use with the @code{MMS} utility.  From the source
-directory, use either
-
-@smallexample
-$ @@[.VMS]VMSBUILD.COM
-@end smallexample
-
-@noindent
-or
-
-@smallexample
-$ MMS/DESCRIPTION=[.VMS]DECSRIP.MMS GAWK
-@end smallexample
-
-Depending upon which C compiler you are using, follow one of the sets
-of instructions in this table:
-
-@table @asis
-@item VAX C V3.x
-Use either @file{vmsbuild.com} or @file{descrip.mms} as is.  These use
-@code{CC/OPTIMIZE=NOLINE}, which is essential for Version 3.0.
-
-@item VAX C V2.x
-You must have Version 2.3 or 2.4; older ones won't work.  Edit either
-@file{vmsbuild.com} or @file{descrip.mms} according to the comments in them.
-For @file{vmsbuild.com}, this just entails removing two @samp{!} delimiters.
-Also edit @file{config.h} (which is a copy of file @file{[.config]vms-conf.h})
-and comment out or delete the two lines @samp{#define __STDC__ 0} and
-@samp{#define VAXC_BUILTINS} near the end.@refill
-
-@item GNU C
-Edit @file{vmsbuild.com} or @file{descrip.mms}; the changes are different
-from those for VAX C V2.x, but equally straightforward.  No changes to
-@file{config.h} should be needed.
-
-@item DEC C
-Edit @file{vmsbuild.com} or @file{descrip.mms} according to their comments.
-No changes to @file{config.h} should be needed.
-@end table
-
-@code{gawk} 2.15 has been tested under VAX/VMS 5.5-1 using VAX C V3.2,
-GNU C 1.40 and 2.3.  It should work without modifications for VMS V4.6 and up.
-
-@node VMS Installation Details, VMS Running, VMS Compilation, VMS Installation
-@subsection Installing @code{gawk} on VMS
-
-To install @code{gawk}, all you need is a ``foreign'' command, which is
-a @code{DCL} symbol whose value begins with a dollar sign.
-
-@smallexample
-$ GAWK :== $device:[directory]GAWK
-@end smallexample
-
-@noindent
-(Substitute the actual location of @code{gawk.exe} for
-@samp{device:[directory]}.) The symbol should be placed in the
-@file{login.com} of any user who wishes to run @code{gawk},
-so that it will be defined every time the user logs on.
-Alternatively, the symbol may be placed in the system-wide
-@file{sylogin.com} procedure, which will allow all users
-to run @code{gawk}.@refill
-
-Optionally, the help entry can be loaded into a VMS help library:
-
-@smallexample
-$ LIBRARY/HELP SYS$HELP:HELPLIB [.VMS]GAWK.HLP
-@end smallexample
-
-@noindent
-(You may want to substitute a site-specific help library rather than
-the standard VMS library @samp{HELPLIB}.)  After loading the help text,
-
-@c this is so tiny, but `should' be smallexample for consistency sake...
-@c I didn't because it was so short.  --mew 29jan1992
-@example
-$ HELP GAWK
-@end example
-
-@noindent
-will provide information about both the @code{gawk} implementation and the
-@code{awk} programming language.
-
-The logical name @samp{AWK_LIBRARY} can designate a default location
-for @code{awk} program files.  For the @samp{-f} option, if the specified
-filename has no device or directory path information in it, @code{gawk}
-will look in the current directory first, then in the directory specified
-by the translation of @samp{AWK_LIBRARY} if the file was not found.
-If after searching in both directories, the file still is not found,
-then @code{gawk} appends the suffix @samp{.awk} to the filename and the
-file search will be re-tried.  If @samp{AWK_LIBRARY} is not defined, that
-portion of the file search will fail benignly.@refill
-
-@node VMS Running, VMS POSIX, VMS Installation Details, VMS Installation
-@subsection Running @code{gawk} on VMS
-
-Command line parsing and quoting conventions are significantly different
-on VMS, so examples in this manual or from other sources often need minor
-changes.  They @emph{are} minor though, and all @code{awk} programs
-should run correctly.
-
-Here are a couple of trivial tests:
-
-@smallexample
-$ gawk -- "BEGIN @{print ""Hello, World!""@}"
-$ gawk -"W" version     ! could also be -"W version" or "-W version"
-@end smallexample
-
-@noindent
-Note that upper-case and mixed-case text must be quoted.
-
-The VMS port of @code{gawk} includes a @code{DCL}-style interface in addition
-to the original shell-style interface (see the help entry for details).
-One side-effect of dual command line parsing is that if there is only a
-single parameter (as in the quoted string program above), the command
-becomes ambiguous.  To work around this, the normally optional @samp{--}
-flag is required to force Unix style rather than @code{DCL} parsing.  If any
-other dash-type options (or multiple parameters such as data files to be
-processed) are present, there is no ambiguity and @samp{--} can be omitted.
-
-The default search path when looking for @code{awk} program files specified
-by the @samp{-f} option is @code{"SYS$DISK:[],AWK_LIBRARY:"}.  The logical
-name @samp{AWKPATH} can be used to override this default.  The format
-of @samp{AWKPATH} is a comma-separated list of directory specifications.
-When defining it, the value should be quoted so that it retains a single
-translation, and not a multi-translation @code{RMS} searchlist.
-
-@node VMS POSIX,  , VMS Running, VMS Installation
-@subsection Building and using @code{gawk} under VMS POSIX
-
-Ignore the instructions above, although @file{vms/gawk.hlp} should still
-be made available in a help library.  Make sure that the two scripts,
-@file{configure} and @file{mungeconf}, are executable; use @samp{chmod +x}
-on them if necessary.  Then execute the following commands:
-
-@smallexample
-$ POSIX
-psx> configure vms-posix
-psx> make awktab.c gawk
-@end smallexample
-
-@noindent
-The first command will construct files @file{config.h} and @file{Makefile}
-out of templates.  The second command will compile and link @code{gawk}.
-Due to a @code{make} bug in VMS POSIX V1.0 and V1.1,
-the file @file{awktab.c} must be given as an explicit target or it will
-not be built and the final link step will fail.  Ignore the warning
-@samp{"Could not find lib m in lib list"}; it is harmless, caused by the
-explicit use of @samp{-lm} as a linker option which is not needed
-under VMS POSIX.  Under V1.1 (but not V1.0) a problem with the @code{yacc}
-skeleton @file{/etc/yyparse.c} will cause a compiler warning for
-@file{awktab.c}, followed by a linker warning about compilation warnings
-in the resulting object module.  These warnings can be ignored.@refill
-
-Once built, @code{gawk} will work like any other shell utility.  Unlike
-the normal VMS port of @code{gawk}, no special command line manipulation is
-needed in the VMS POSIX environment.
-
-@node MS-DOS Installation, Atari Installation, VMS Installation, Installation
-@section Installing @code{gawk} on MS-DOS
-
-@cindex installation, ms-dos
-The first step is to get all the files in the @code{gawk} distribution
-onto your PC.  Move all the files from the @file{pc} directory into
-the main directory where the other files are.  Edit the file
-@file{make.bat} so that it will be an acceptable MS-DOS batch file.
-This means making sure that all lines are terminated with the ASCII
-carriage return and line feed characters.
-restrictions.
-
-@code{gawk} has only been compiled with version 5.1 of the Microsoft
-C compiler.  The file @file{make.bat} from the @file{pc} directory
-assumes that you have this compiler.
-
-Copy the file @file{setargv.obj} from the library directory where it
-resides to the @code{gawk} source code directory.
-
-Run @file{make.bat}.  This will compile @code{gawk} for you, and link it.
-That's all there is to it!
-
-@node Atari Installation,  , MS-DOS Installation, Installation
-@section Installing @code{gawk} on the Atari ST
-
-@c based on material from
-@c Michal Jaegermann <ntomczak@vm.ucs.ualberta.ca>
-
-@cindex installation, atari
-This section assumes that you are running TOS.  It applies to other Atari
-models (STe, TT) as well.
-
-In order to use @code{gawk}, you need to have a shell, either text or
-graphics, that does not map all the characters of a command line to
-upper case.  Maintaining case distinction in option flags is very
-important (@pxref{Command Line, ,Invoking @code{awk}}).  Popular shells
-like @code{gulam} or @code{gemini} will work, as will newer versions of
-@code{desktop}.  Support for I/O redirection is necessary to make it easy
-to import @code{awk} programs from other environments.  Pipes are nice to have,
-but not vital.
-
-If you have received an executable version of @code{gawk}, place it,
-as usual, anywhere in your @code{PATH} where your shell will find it.
-
-While executing, @code{gawk} creates a number of temporary files.
-@code{gawk} looks for either of the environment variables @code{TEMP}
-or @code{TMPDIR}, in that order.  If either one is found, its value
-is assumed to be a directory for temporary files.  This directory
-must exist, and if you can spare the memory, it is a good idea to
-put it on a @sc{ram} drive.  If neither @code{TEMP} nor @code{TMPDIR}
-are found, then @code{gawk} uses the current directory for its
-temporary files.
-
-The ST version of @code{gawk} searches for its program files as
-described in @ref{AWKPATH Variable, ,The @code{AWKPATH} Environment Variable}.
-On the ST, the default value for the @code{AWKPATH} variable is
-@code{@w{".,c:\lib\awk,c:\gnu\lib\awk"}}.
-The search path can be modified by explicitly setting @code{AWKPATH} to
-whatever you wish.  Note that colons cannot be used on the ST to separate
-elements in the @code{AWKPATH} variable, since they have another, reserved,
-meaning.  Instead, you must use a comma to separate elements in the path.
-If you are recompiling @code{gawk} on the ST, then you can choose a new
-default search path, by setting the value of @samp{DEFPATH} in the file
-@file{...\config\atari}.  You may choose a different separator character
-by setting the value of @samp{ENVSEP} in the same file.  The new values will
-be used when creating the header file @file{config.h}.@refill
-
-@ignore
-As a last resort, small
-adjustments can be made directly on the executable version of @code{gawk}
-using a binary editor.@refill
-@end ignore
-
-Although @code{awk} allows great flexibility in doing I/O redirections
-from within a program, this facility should be used with care on the ST.
-In some circumstances the OS routines for file handle pool processing
-lose track of certain events, causing the computer to crash, and requiring
-a reboot.  Often a warm reboot is sufficient.  Fortunately, this happens
-infrequently, and in rather esoteric situations.  In particular, avoid
-having one part of an @code{awk} program using @code{print}
-statements explicitly redirected to @code{"/dev/stdout"}, while other
-@code{print} statements use the default standard output, and a
-calling shell has redirected standard output to a file.@refill
-@c whew!
-
-When @code{gawk} is compiled with the ST version of @code{gcc} and its
-usual libraries, it will accept both @samp{/} and @samp{\} as path separators.
-While this is convenient, it should be remembered that this removes one,
-technically legal, character (@samp{/}) from your file names, and that
-it may create problems for external programs, called via the @code{system()}
-function, which may not support this convention.  Whenever it is possible
-that a file created by @code{gawk} will be used by some other program,
-use only backslashes.  Also remember that in @code{awk}, backslashes in
-strings have to be doubled in order to get literal backslashes.
-
-The initial port of @code{gawk} to the ST was done with @code{gcc}.
-If you wish to recompile @code{gawk} from scratch, you will need to use
-a compiler that accepts @sc{ansi} standard C (such as @code{gcc}, Turbo C,
-or Prospero C).  If @code{sizeof(int) != @w{sizeof(int *)}}, the correctness
-of the generated code depends heavily on the fact that all function calls
-have function prototypes in the current scope.  If your compiler does
-not accept function prototypes, you will probably have to add a
-number of casts to the code.@refill
-
-If you are using @code{gcc}, make sure that you have up-to-date libraries.
-Older versions have problems with some library functions (@code{atan2()},
-@code{strftime()}, the @samp{%g} conversion in @code{sprintf()}) which
-may affect the operation of @code{gawk}.
-
-In the @file{atari} subdirectory of the @code{gawk} distribution is
-a version of the @code{system()} function that has been tested with
-@code{gulam} and @code{msh}; it should work with other shells as well.
-With @code{gulam}, it passes the string to be executed without spawning
-an extra copy of a shell.  It is possible to replace this version of
-@code{system()} with a similar function from a library or from some other
-source if that version would be a better choice for the shell you prefer.
-
-The files needed to recompile @code{gawk} on the ST can be found in
-the @file{atari} directory.  The provided files and instructions below
-assume that you have the GNU C compiler (@code{gcc}), the @code{gulam} shell,
-and an ST version of @code{sed}. The @file{Makefile} is set up to use
-@file{byacc} as a @file{yacc} replacement.  With a different set of tools some
-adjustments and/or editing will be needed.@refill
-
-@code{cd} to the @file{atari} directory.  Copy @file{Makefile.st} to
-@file{makefile} in the source (parent) directory.  Possibly adjust
-@file{../config/atari} to suit your system.  Execute the script @file{mkconf.g}
-which will create the header file @file{../config.h}.  Go back to the source
-directory.  If you are not using @code{gcc}, check the file @file{missing.c}.
-It may be necessary to change forward slashes in the references to files
-from the @file{atari} subdirectory into backslashes.  Type @code{make} and
-enjoy.@refill
-
-Compilation with @code{gcc} of some of the bigger modules, like
-@file{awk_tab.c}, may require a full four megabytes of memory.  On smaller
-machines you would need to cut down on optimizations, or you would have to
-switch to another, less memory hungry, compiler.@refill
-
-@node Gawk Summary, Sample Program, Installation, Top
-@appendix @code{gawk} Summary
-
-This appendix provides a brief summary of the @code{gawk} command line and the
-@code{awk} language.  It is designed to serve as ``quick reference.''  It is
-therefore terse, but complete.
-
-@menu
-* Command Line Summary::        Recapitulation of the command line.
-* Language Summary::            A terse review of the language.
-* Variables/Fields::            Variables, fields, and arrays.
-* Rules Summary::               Patterns and Actions, and their 
-                                component parts.
-* Functions Summary::           Defining and calling functions.
-* Historical Features::         Some undocumented but supported ``features''.
-@end menu
-
-@node Command Line Summary, Language Summary, Gawk Summary, Gawk Summary
-@appendixsec Command Line Options Summary
-
-The command line consists of options to @code{gawk} itself, the
-@code{awk} program text (if not supplied via the @samp{-f} option), and
-values to be made available in the @code{ARGC} and @code{ARGV}
-predefined @code{awk} variables:
-
-@example
-awk @r{[@var{POSIX or GNU style options}]} -f source-file @r{[@code{--}]} @var{file} @dots{}
-awk @r{[@var{POSIX or GNU style options}]} @r{[@code{--}]} '@var{program}' @var{file} @dots{}
-@end example
-
-The options that @code{gawk} accepts are:
-
-@table @code
-@item -F @var{fs}
-@itemx --field-separator=@var{fs}
-Use @var{fs} for the input field separator (the value of the @code{FS}
-predefined variable).
-
-@item -f @var{program-file}
-@itemx --file=@var{program-file}
-Read the @code{awk} program source from the file @var{program-file}, instead
-of from the first command line argument.
-
-@item -v @var{var}=@var{val}
-@itemx --assign=@var{var}=@var{val}
-Assign the variable @var{var} the value @var{val} before program execution
-begins.
-
-@item -W compat
-@itemx --compat
-Specifies compatibility mode, in which @code{gawk} extensions are turned
-off.
-
-@item -W copyleft
-@itemx -W copyright
-@itemx --copyleft
-@itemx --copyright
-Print the short version of the General Public License on the error
-output.  This option may disappear in a future version of @code{gawk}.
-
-@item -W help
-@itemx -W usage
-@itemx --help
-@itemx --usage
-Print a relatively short summary of the available options on the error output.
-
-@item -W lint
-@itemx --lint
-Give warnings about dubious or non-portable @code{awk} constructs.
-
-@item -W posix
-@itemx --posix
-Specifies @sc{posix} compatibility mode, in which @code{gawk} extensions
-are turned off and additional restrictions apply.
-
-@item -W source=@var{program-text}
-@itemx --source=@var{program-text}
-Use @var{program-text} as @code{awk} program source code.  This option allows
-mixing command line source code with source code from files, and is
-particularly useful for mixing command line programs with library functions.
-
-@item -W version
-@itemx --version
-Print version information for this particular copy of @code{gawk} on the error
-output.  This option may disappear in a future version of @code{gawk}.
-
-@item --
-Signal the end of options.  This is useful to allow further arguments to the
-@code{awk} program itself to start with a @samp{-}.  This is mainly for
-consistency with the argument parsing conventions of @sc{posix}.
-@end table
-
-Any other options are flagged as invalid, but are otherwise ignored.
-@xref{Command Line, ,Invoking @code{awk}}, for more details.
-
-@node Language Summary, Variables/Fields, Command Line Summary, Gawk Summary
-@appendixsec Language Summary
-
-An @code{awk} program consists of a sequence of pattern-action statements
-and optional function definitions.
-
-@example
-@var{pattern}    @{ @var{action statements} @}
-
-function @var{name}(@var{parameter list})     @{ @var{action statements} @}
-@end example
-
-@code{gawk} first reads the program source from the
-@var{program-file}(s) if specified, or from the first non-option
-argument on the command line.  The @samp{-f} option may be used multiple
-times on the command line.  @code{gawk} reads the program text from all
-the @var{program-file} files, effectively concatenating them in the
-order they are specified.  This is useful for building libraries of
-@code{awk} functions, without having to include them in each new
-@code{awk} program that uses them.  To use a library function in a file
-from a program typed in on the command line, specify @samp{-f /dev/tty};
-then type your program, and end it with a @kbd{Control-d}.
-@xref{Command Line, ,Invoking @code{awk}}.@refill
-
-The environment variable @code{AWKPATH} specifies a search path to use
-when finding source files named with the @samp{-f} option.  The default
-path, which is
-@samp{.:/usr/lib/awk:/usr/local/lib/awk} is used if @code{AWKPATH} is not set.
-If a file name given to the @samp{-f} option contains a @samp{/} character,
-no path search is performed.
-@xref{AWKPATH Variable, ,The @code{AWKPATH} Environment Variable},
-for a full description of the @code{AWKPATH} environment variable.@refill
-
-@code{gawk} compiles the program into an internal form, and then proceeds to
-read each file named in the @code{ARGV} array.  If there are no files named
-on the command line, @code{gawk} reads the standard input.
-
-If a ``file'' named on the command line has the form
-@samp{@var{var}=@var{val}}, it is treated as a variable assignment: the
-variable @var{var} is assigned the value @var{val}.
-If any of the files have a value that is the null string, that
-element in the list is skipped.@refill
-
-For each line in the input, @code{gawk} tests to see if it matches any
-@var{pattern} in the @code{awk} program.  For each pattern that the line
-matches, the associated @var{action} is executed.
-
-@node Variables/Fields, Rules Summary, Language Summary, Gawk Summary
-@appendixsec Variables and Fields
-
-@code{awk} variables are dynamic; they come into existence when they are
-first used.  Their values are either floating-point numbers or strings.
-@code{awk} also has one-dimension arrays; multiple-dimensional arrays
-may be simulated.  There are several predefined variables that
-@code{awk} sets as a program runs; these are summarized below.
-
-@menu
-* Fields Summary::              Input field splitting.
-* Built-in Summary::            @code{awk}'s built-in variables.
-* Arrays Summary::              Using arrays.
-* Data Type Summary::           Values in @code{awk} are numbers or strings.
-@end menu
-
-@node Fields Summary, Built-in Summary, Variables/Fields, Variables/Fields
-@appendixsubsec Fields
-
-As each input line is read, @code{gawk} splits the line into
-@var{fields}, using the value of the @code{FS} variable as the field
-separator.  If @code{FS} is a single character, fields are separated by
-that character.  Otherwise, @code{FS} is expected to be a full regular
-expression.  In the special case that @code{FS} is a single blank,
-fields are separated by runs of blanks and/or tabs.  Note that the value
-of @code{IGNORECASE} (@pxref{Case-sensitivity, ,Case-sensitivity in Matching})
-also affects how fields are split when @code{FS} is a regular expression.@refill
-
-Each field in the input line may be referenced by its position, @code{$1},
-@code{$2}, and so on.  @code{$0} is the whole line.  The value of a field may
-be assigned to as well.  Field numbers need not be constants:
-
-@example
-n = 5
-print $n
-@end example
-
-@noindent
-prints the fifth field in the input line.  The variable @code{NF} is set to
-the total number of fields in the input line.
-
-References to nonexistent fields (i.e., fields after @code{$NF}) return
-the null-string.  However, assigning to a nonexistent field (e.g.,
-@code{$(NF+2) = 5}) increases the value of @code{NF}, creates any
-intervening fields with the null string as their value, and causes the
-value of @code{$0} to be recomputed, with the fields being separated by
-the value of @code{OFS}.@refill
-
-@xref{Reading Files, ,Reading Input Files}, for a full description of the
-way @code{awk} defines and uses fields.
-
-@node Built-in Summary, Arrays Summary, Fields Summary, Variables/Fields
-@appendixsubsec Built-in Variables
-
-@code{awk}'s built-in variables are:
-
-@table @code
-@item ARGC
-The number of command line arguments (not including options or the
-@code{awk} program itself).
-
-@item ARGIND
-The index in @code{ARGV} of the current file being processed.
-It is always true that @samp{FILENAME == ARGV[ARGIND]}.
-
-@item ARGV
-The array of command line arguments.  The array is indexed from 0 to
-@code{ARGC} @minus{} 1.  Dynamically changing the contents of @code{ARGV}
-can control the files used for data.@refill
-
-@item CONVFMT
-The conversion format to use when converting numbers to strings.
-
-@item FIELDWIDTHS
-A space separated list of numbers describing the fixed-width input data.
-
-@item ENVIRON
-An array containing the values of the environment variables.  The array
-is indexed by variable name, each element being the value of that
-variable.  Thus, the environment variable @code{HOME} would be in
-@code{ENVIRON["HOME"]}.  Its value might be @file{/u/close}.
-
-Changing this array does not affect the environment seen by programs
-which @code{gawk} spawns via redirection or the @code{system} function.
-(This may change in a future version of @code{gawk}.)
-
-Some operating systems do not have environment variables.
-The array @code{ENVIRON} is empty when running on these systems.
-
-@item ERRNO
-The system error message when an error occurs using @code{getline}
-or @code{close}.
-
-@item FILENAME
-The name of the current input file.  If no files are specified on the command
-line, the value of @code{FILENAME} is @samp{-}.
-
-@item FNR
-The input record number in the current input file.
-
-@item FS
-The input field separator, a blank by default.
-
-@item IGNORECASE
-The case-sensitivity flag for regular expression operations.  If
-@code{IGNORECASE} has a nonzero value, then pattern matching in rules,
-field splitting with @code{FS}, regular expression matching with
-@samp{~} and @samp{!~}, and the @code{gsub}, @code{index}, @code{match},
-@code{split} and @code{sub} predefined functions all ignore case
-when doing regular expression operations.@refill
-
-@item NF
-The number of fields in the current input record.
-
-@item NR
-The total number of input records seen so far.
-
-@item OFMT
-The output format for numbers for the @code{print} statement,
-@code{"%.6g"} by default.
-
-@item OFS
-The output field separator, a blank by default.
-
-@item ORS
-The output record separator, by default a newline.
-
-@item RS
-The input record separator, by default a newline.  @code{RS} is exceptional
-in that only the first character of its string value is used for separating
-records.  If @code{RS} is set to the null string, then records are separated by
-blank lines.  When @code{RS} is set to the null string, then the newline
-character always acts as a field separator, in addition to whatever value
-@code{FS} may have.@refill
-
-@item RSTART
-The index of the first character matched by @code{match}; 0 if no match.
-
-@item RLENGTH
-The length of the string matched by @code{match}; @minus{}1 if no match.
-
-@item SUBSEP
-The string used to separate multiple subscripts in array elements, by
-default @code{"\034"}.
-@end table
-
-@xref{Built-in Variables}, for more information.
-
-@node Arrays Summary, Data Type Summary, Built-in Summary, Variables/Fields
-@appendixsubsec Arrays
-
-Arrays are subscripted with an expression between square brackets
-(@samp{[} and @samp{]}).  Array subscripts are @emph{always} strings;
-numbers are converted to strings as necessary, following the standard
-conversion rules
-(@pxref{Conversion, ,Conversion of Strings and Numbers}).@refill
-
-If you use multiple expressions separated by commas inside the square
-brackets, then the array subscript is a string consisting of the
-concatenation of the individual subscript values, converted to strings,
-separated by the subscript separator (the value of @code{SUBSEP}).
-
-The special operator @code{in} may be used in an @code{if} or
-@code{while} statement to see if an array has an index consisting of a
-particular value.
-
-@example
-if (val in array)
-        print array[val]
-@end example
-
-If the array has multiple subscripts, use @code{(i, j, @dots{}) in array}
-to test for existence of an element.
-
-The @code{in} construct may also be used in a @code{for} loop to iterate
-over all the elements of an array.
-@xref{Scanning an Array, ,Scanning all Elements of an Array}.@refill
-
-An element may be deleted from an array using the @code{delete} statement.
-
-@xref{Arrays, ,Arrays in @code{awk}}, for more detailed information.
-
-@node Data Type Summary,  , Arrays Summary, Variables/Fields
-@appendixsubsec Data Types
-
-The value of an @code{awk} expression is always either a number
-or a string.
-
-Certain contexts (such as arithmetic operators) require numeric
-values.  They convert strings to numbers by interpreting the text
-of the string as a numeral.  If the string does not look like a
-numeral, it converts to 0.
-
-Certain contexts (such as concatenation) require string values.
-They convert numbers to strings by effectively printing them
-with @code{sprintf}.
-@xref{Conversion, ,Conversion of Strings and Numbers}, for the details.@refill
-
-To force conversion of a string value to a number, simply add 0
-to it.  If the value you start with is already a number, this
-does not change it.
-
-To force conversion of a numeric value to a string, concatenate it with
-the null string.
-
-The @code{awk} language defines comparisons as being done numerically if
-both operands are numeric, or if one is numeric and the other is a numeric
-string.  Otherwise one or both operands are converted to strings and a
-string comparison is performed.
-
-Uninitialized variables have the string value @code{""} (the null, or
-empty, string).  In contexts where a number is required, this is
-equivalent to 0.
-
-@xref{Variables}, for more information on variable naming and initialization;
-@pxref{Conversion, ,Conversion of Strings and Numbers}, for more information
-on how variable values are interpreted.@refill
-
-@node Rules Summary, Functions Summary, Variables/Fields, Gawk Summary
-@appendixsec Patterns and Actions
-
-@menu
-* Pattern Summary::             Quick overview of patterns.
-* Regexp Summary::              Quick overview of regular expressions.
-* Actions Summary::             Quick overview of actions.
-@end menu
-
-An @code{awk} program is mostly composed of rules, each consisting of a
-pattern followed by an action.  The action is enclosed in @samp{@{} and
-@samp{@}}.  Either the pattern may be missing, or the action may be
-missing, but, of course, not both.  If the pattern is missing, the
-action is executed for every single line of input.  A missing action is
-equivalent to this action,
-
-@example
-@{ print @}
-@end example
-
-@noindent
-which prints the entire line.
-
-Comments begin with the @samp{#} character, and continue until the end of the
-line.  Blank lines may be used to separate statements.  Normally, a statement
-ends with a newline, however, this is not the case for lines ending in a
-@samp{,}, @samp{@{}, @samp{?}, @samp{:}, @samp{&&}, or @samp{||}.  Lines
-ending in @code{do} or @code{else} also have their statements automatically
-continued on the following line.  In other cases, a line can be continued by
-ending it with a @samp{\}, in which case the newline is ignored.@refill
-
-Multiple statements may be put on one line by separating them with a @samp{;}.
-This applies to both the statements within the action part of a rule (the
-usual case), and to the rule statements.
-
-@xref{Comments, ,Comments in @code{awk} Programs}, for information on
-@code{awk}'s commenting convention;
-@pxref{Statements/Lines, ,@code{awk} Statements versus Lines}, for a
-description of the line continuation mechanism in @code{awk}.@refill
-
-@node Pattern Summary, Regexp Summary, Rules Summary, Rules Summary
-@appendixsubsec Patterns
-
-@code{awk} patterns may be one of the following:
-
-@example
-/@var{regular expression}/
-@var{relational expression}
-@var{pattern} && @var{pattern}
-@var{pattern} || @var{pattern}
-@var{pattern} ? @var{pattern} : @var{pattern}
-(@var{pattern})
-! @var{pattern}
-@var{pattern1}, @var{pattern2}
-BEGIN
-END
-@end example
-
-@code{BEGIN} and @code{END} are two special kinds of patterns that are not
-tested against the input.  The action parts of all @code{BEGIN} rules are
-merged as if all the statements had been written in a single @code{BEGIN}
-rule.  They are executed before any of the input is read.  Similarly, all the
-@code{END} rules are merged, and executed when all the input is exhausted (or
-when an @code{exit} statement is executed).  @code{BEGIN} and @code{END}
-patterns cannot be combined with other patterns in pattern expressions.
-@code{BEGIN} and @code{END} rules cannot have missing action parts.@refill
-
-For @samp{/@var{regular-expression}/} patterns, the associated statement is
-executed for each input line that matches the regular expression.  Regular
-expressions are extensions of those in @code{egrep}, and are summarized below.
-
-A @var{relational expression} may use any of the operators defined below in
-the section on actions.  These generally test whether certain fields match
-certain regular expressions.
-
-The @samp{&&}, @samp{||}, and @samp{!} operators are logical ``and,''
-logical ``or,'' and logical ``not,'' respectively, as in C.  They do
-short-circuit evaluation, also as in C, and are used for combining more
-primitive pattern expressions.  As in most languages, parentheses may be
-used to change the order of evaluation.
-
-The @samp{?:} operator is like the same operator in C.  If the first
-pattern matches, then the second pattern is matched against the input
-record; otherwise, the third is matched.  Only one of the second and
-third patterns is matched.
-
-The @samp{@var{pattern1}, @var{pattern2}} form of a pattern is called a
-range pattern.  It matches all input lines starting with a line that
-matches @var{pattern1}, and continuing until a line that matches
-@var{pattern2}, inclusive.  A range pattern cannot be used as an operand
-to any of the pattern operators.
-
-@xref{Patterns}, for a full description of the pattern part of @code{awk}
-rules.
-
-@node Regexp Summary, Actions Summary, Pattern Summary, Rules Summary
-@appendixsubsec Regular Expressions
-
-Regular expressions are the extended kind found in @code{egrep}.
-They are composed of characters as follows:
-
-@table @code
-@item @var{c}
-matches the character @var{c} (assuming @var{c} is a character with no
-special meaning in regexps).
-
-@item \@var{c}
-matches the literal character @var{c}.
-
-@item .
-matches any character except newline.
-
-@item ^
-matches the beginning of a line or a string.
-
-@item $
-matches the end of a line or a string.
-
-@item [@var{abc}@dots{}]
-matches any of the characters @var{abc}@dots{} (character class).
-
-@item [^@var{abc}@dots{}]
-matches any character except @var{abc}@dots{} and newline (negated
-character class).
-
-@item @var{r1}|@var{r2}
-matches either @var{r1} or @var{r2} (alternation).
-
-@item @var{r1r2}
-matches @var{r1}, and then @var{r2} (concatenation).
-
-@item @var{r}+
-matches one or more @var{r}'s.
-
-@item @var{r}*
-matches zero or more @var{r}'s. 
-
-@item @var{r}?
-matches zero or one @var{r}'s. 
-
-@item (@var{r})
-matches @var{r} (grouping).
-@end table
-
-@xref{Regexp, ,Regular Expressions as Patterns}, for a more detailed
-explanation of regular expressions.
-
-The escape sequences allowed in string constants are also valid in
-regular expressions (@pxref{Constants, ,Constant Expressions}).
-
-@node Actions Summary,  , Regexp Summary, Rules Summary
-@appendixsubsec Actions
-
-Action statements are enclosed in braces, @samp{@{} and @samp{@}}.
-Action statements consist of the usual assignment, conditional, and looping
-statements found in most languages.  The operators, control statements,
-and input/output statements available are patterned after those in C.
-
-@menu
-* Operator Summary::            @code{awk} operators.
-* Control Flow Summary::        The control statements.
-* I/O Summary::                 The I/O statements.
-* Printf Summary::              A summary of @code{printf}.
-* Special File Summary::        Special file names interpreted internally.
-* Numeric Functions Summary::   Built-in numeric functions.
-* String Functions Summary::    Built-in string functions.
-* Time Functions Summary::      Built-in time functions.
-* String Constants Summary::    Escape sequences in strings.
-@end menu
-
-@node Operator Summary, Control Flow Summary, Actions Summary, Actions Summary
-@appendixsubsubsec Operators
-
-The operators in @code{awk}, in order of increasing precedence, are:
-
-@table @code
-@item = += -= *= /= %= ^=
-Assignment.  Both absolute assignment (@code{@var{var}=@var{value}})
-and operator assignment (the other forms) are supported.
-
-@item ?:
-A conditional expression, as in C.  This has the form @code{@var{expr1} ?
-@var{expr2} : @var{expr3}}.  If @var{expr1} is true, the value of the
-expression is @var{expr2}; otherwise it is @var{expr3}.  Only one of
-@var{expr2} and @var{expr3} is evaluated.@refill
-
-@item ||
-Logical ``or''.
-
-@item &&
-Logical ``and''.
-
-@item ~ !~
-Regular expression match, negated match.
-
-@item < <= > >= != ==
-The usual relational operators.
-
-@item @var{blank}
-String concatenation.
-
-@item + -
-Addition and subtraction.
-
-@item * / %
-Multiplication, division, and modulus.
-
-@item + - !
-Unary plus, unary minus, and logical negation.
-
-@item ^
-Exponentiation (@samp{**} may also be used, and @samp{**=} for the assignment
-operator, but they are not specified in the @sc{posix} standard).
-
-@item ++ --
-Increment and decrement, both prefix and postfix.
-
-@item $
-Field reference.
-@end table
-
-@xref{Expressions, ,Expressions as Action Statements}, for a full
-description of all the operators listed above.
-@xref{Fields, ,Examining Fields}, for a description of the field
-reference operator.@refill
-
-@node Control Flow Summary, I/O Summary, Operator Summary, Actions Summary
-@appendixsubsubsec Control Statements
-
-The control statements are as follows:
-
-@example
-if (@var{condition}) @var{statement} @r{[} else @var{statement} @r{]}
-while (@var{condition}) @var{statement}
-do @var{statement} while (@var{condition})
-for (@var{expr1}; @var{expr2}; @var{expr3}) @var{statement}
-for (@var{var} in @var{array}) @var{statement}
-break
-continue
-delete @var{array}[@var{index}]
-exit @r{[} @var{expression} @r{]}
-@{ @var{statements} @}
-@end example
-
-@xref{Statements, ,Control Statements in Actions}, for a full description
-of all the control statements listed above.
-
-@node I/O Summary, Printf Summary, Control Flow Summary, Actions Summary
-@appendixsubsubsec I/O Statements
-
-The input/output statements are as follows:
-
-@table @code
-@item getline
-Set @code{$0} from next input record; set @code{NF}, @code{NR}, @code{FNR}.
-
-@item getline <@var{file}
-Set @code{$0} from next record of @var{file}; set @code{NF}.
-
-@item getline @var{var}
-Set @var{var} from next input record; set @code{NF}, @code{FNR}.
-
-@item getline @var{var} <@var{file}
-Set @var{var} from next record of @var{file}.
-
-@item next
-Stop processing the current input record.  The next input record is read and
-processing starts over with the first pattern in the @code{awk} program.
-If the end of the input data is reached, the @code{END} rule(s), if any,
-are executed.
-
-@item next file
-Stop processing the current input file.  The next input record read comes
-from the next input file.  @code{FILENAME} is updated, @code{FNR} is set to 1, 
-and processing starts over with the first pattern in the @code{awk} program.
-If the end of the input data is reached, the @code{END} rule(s), if any,
-are executed.
-
-@item print
-Prints the current record.
-
-@item print @var{expr-list}
-Prints expressions.
-
-@item print @var{expr-list} > @var{file}
-Prints expressions on @var{file}.
-
-@item printf @var{fmt, expr-list}
-Format and print.
-
-@item printf @var{fmt, expr-list} > file
-Format and print on @var{file}.
-@end table
-
-Other input/output redirections are also allowed.  For @code{print} and
-@code{printf}, @samp{>> @var{file}} appends output to the @var{file},
-and @samp{| @var{command}} writes on a pipe.  In a similar fashion,
-@samp{@var{command} | getline} pipes input into @code{getline}.
-@code{getline} returns 0 on end of file, and @minus{}1 on an error.@refill
-
-@xref{Getline, ,Explicit Input with @code{getline}}, for a full description
-of the @code{getline} statement.
-@xref{Printing, ,Printing Output}, for a full description of @code{print} and
-@code{printf}.  Finally, @pxref{Next Statement, ,The @code{next} Statement},
-for a description of how the @code{next} statement works.@refill
-
-@node Printf Summary, Special File Summary, I/O Summary, Actions Summary
-@appendixsubsubsec @code{printf} Summary
-
-The @code{awk} @code{printf} statement and @code{sprintf} function
-accept the following conversion specification formats:
-
-@table @code
-@item %c
-An ASCII character.  If the argument used for @samp{%c} is numeric, it is
-treated as a character and printed.  Otherwise, the argument is assumed to
-be a string, and the only first character of that string is printed.
-
-@item %d
-@itemx %i
-A decimal number (the integer part).
-
-@item %e
-A floating point number of the form
-@samp{@r{[}-@r{]}d.ddddddE@r{[}+-@r{]}dd}.@refill
-
-@item %f
-A floating point number of the form
-@r{[}@code{-}@r{]}@code{ddd.dddddd}.
-
-@item %g
-Use @samp{%e} or @samp{%f} conversion, whichever produces a shorter string,
-with nonsignificant zeros suppressed.
-
-@item %o
-An unsigned octal number (again, an integer).
-
-@item %s
-A character string.
-
-@item %x
-An unsigned hexadecimal number (an integer).
-
-@item %X
-Like @samp{%x}, except use @samp{A} through @samp{F} instead of @samp{a}
-through @samp{f} for decimal 10 through 15.@refill
-
-@item %%
-A single @samp{%} character; no argument is converted.
-@end table
-
-There are optional, additional parameters that may lie between the @samp{%}
-and the control letter:
-
-@table @code
-@item -
-The expression should be left-justified within its field.
-
-@item @var{width}
-The field should be padded to this width.  If @var{width} has a leading zero,
-then the field is padded with zeros.  Otherwise it is padded with blanks.
-
-@item .@var{prec}
-A number indicating the maximum width of strings or digits to the right
-of the decimal point.
-@end table
-
-Either or both of the @var{width} and @var{prec} values may be specified
-as @samp{*}.  In that case, the particular value is taken from the argument
-list.
-
-@xref{Printf, ,Using @code{printf} Statements for Fancier Printing}, for
-examples and for a more detailed description.
-
-@node Special File Summary, Numeric Functions Summary, Printf Summary, Actions Summary
-@appendixsubsubsec Special File Names
-
-When doing I/O redirection from either @code{print} or @code{printf} into a
-file, or via @code{getline} from a file, @code{gawk} recognizes certain special
-file names internally.  These file names allow access to open file descriptors
-inherited from @code{gawk}'s parent process (usually the shell).  The
-file names are:
-
-@table @file
-@item /dev/stdin
-The standard input.
-
-@item /dev/stdout
-The standard output.
-
-@item /dev/stderr
-The standard error output.
-
-@item /dev/fd/@var{n}
-The file denoted by the open file descriptor @var{n}.
-@end table
-
-In addition the following files provide process related information
-about the running @code{gawk} program.
-
-@table @file
-@item /dev/pid
-Reading this file returns the process ID of the current process,
-in decimal, terminated with a newline.
-
-@item  /dev/ppid
-Reading this file returns the parent process ID of the current process,
-in decimal, terminated with a newline.
-
-@item  /dev/pgrpid
-Reading this file returns the process group ID of the current process,
-in decimal, terminated with a newline.
-
-@item /dev/user
-Reading this file returns a single record terminated with a newline.
-The fields are separated with blanks.  The fields represent the
-following information:
-
-@table @code
-@item $1
-The value of the @code{getuid} system call.
-
-@item $2
-The value of the @code{geteuid} system call.
-
-@item $3
-The value of the @code{getgid} system call.
-
-@item $4
-The value of the @code{getegid} system call.
-@end table
-
-If there are any additional fields, they are the group IDs returned by
-@code{getgroups} system call.
-(Multiple groups may not be supported on all systems.)@refill
-@end table
-
-@noindent
-These file names may also be used on the command line to name data files.
-These file names are only recognized internally if you do not
-actually have files by these names on your system.
-
-@xref{Special Files, ,Standard I/O Streams}, for a longer description that
-provides the motivation for this feature.
-
-@node Numeric Functions Summary, String Functions Summary, Special File Summary, Actions Summary
-@appendixsubsubsec Numeric Functions
-
-@code{awk} has the following predefined arithmetic functions:
-
-@table @code
-@item atan2(@var{y}, @var{x})
-returns the arctangent of @var{y/x} in radians.
-
-@item cos(@var{expr})
-returns the cosine in radians.
-
-@item exp(@var{expr})
-the exponential function.
-
-@item int(@var{expr})
-truncates to integer.
-
-@item log(@var{expr})
-the natural logarithm function.
-
-@item rand()
-returns a random number between 0 and 1.
-
-@item sin(@var{expr})
-returns the sine in radians.
-
-@item sqrt(@var{expr})
-the square root function.
-
-@item srand(@var{expr})
-use @var{expr} as a new seed for the random number generator.  If no @var{expr}
-is provided, the time of day is used.  The return value is the previous
-seed for the random number generator.
-@end table
-
-@node String Functions Summary, Time Functions Summary, Numeric Functions Summary, Actions Summary
-@appendixsubsubsec String Functions
-
-@code{awk} has the following predefined string functions:
-
-@table @code
-@item gsub(@var{r}, @var{s}, @var{t})
-for each substring matching the regular expression @var{r} in the string
-@var{t}, substitute the string @var{s}, and return the number of substitutions.
-If @var{t} is not supplied, use @code{$0}.
-
-@item index(@var{s}, @var{t})
-returns the index of the string @var{t} in the string @var{s}, or 0 if
-@var{t} is not present.
-
-@item length(@var{s})
-returns the length of the string @var{s}.  The length of @code{$0}
-is returned if no argument is supplied.
-
-@item match(@var{s}, @var{r})
-returns the position in @var{s} where the regular expression @var{r}
-occurs, or 0 if @var{r} is not present, and sets the values of @code{RSTART}
-and @code{RLENGTH}.
-
-@item split(@var{s}, @var{a}, @var{r})
-splits the string @var{s} into the array @var{a} on the regular expression
-@var{r}, and returns the number of fields.  If @var{r} is omitted, @code{FS}
-is used instead.
-
-@item sprintf(@var{fmt}, @var{expr-list})
-prints @var{expr-list} according to @var{fmt}, and returns the resulting string.
-
-@item sub(@var{r}, @var{s}, @var{t})
-this is just like @code{gsub}, but only the first matching substring is
-replaced.
-
-@item substr(@var{s}, @var{i}, @var{n})
-returns the @var{n}-character substring of @var{s} starting at @var{i}.
-If @var{n} is omitted, the rest of @var{s} is used.
-
-@item tolower(@var{str})
-returns a copy of the string @var{str}, with all the upper-case characters in
-@var{str} translated to their corresponding lower-case counterparts.
-Nonalphabetic characters are left unchanged.
-
-@item toupper(@var{str})
-returns a copy of the string @var{str}, with all the lower-case characters in
-@var{str} translated to their corresponding upper-case counterparts.
-Nonalphabetic characters are left unchanged.
-
-@item system(@var{cmd-line})
-Execute the command @var{cmd-line}, and return the exit status.
-@end table
-
-@node Time Functions Summary, String Constants Summary, String Functions Summary, Actions Summary
-@appendixsubsubsec  Built-in time functions
-
-The following two functions are available for getting the current
-time of day, and for formatting time stamps.
-
-@table @code
-@item systime()
-returns the current time of day as the number of seconds since a particular
-epoch (Midnight, January 1, 1970 @sc{utc}, on @sc{posix} systems).
-
-@item strftime(@var{format}, @var{timestamp})
-formats @var{timestamp} according to the specification in @var{format}.
-The current time of day is used if no @var{timestamp} is supplied.
-@xref{Time Functions, ,Functions for Dealing with Time Stamps}, for the
-details on the conversion specifiers that @code{strftime} accepts.@refill
-@end table
-
-@iftex
-@xref{Built-in, ,Built-in Functions}, for a description of all of
-@code{awk}'s built-in functions.
-@end iftex
-
-@node String Constants Summary,  , Time Functions Summary, Actions Summary
-@appendixsubsubsec String Constants
-
-String constants in @code{awk} are sequences of characters enclosed
-between double quotes (@code{"}).  Within strings, certain @dfn{escape sequences}
-are recognized, as in C.  These are:
-
-@table @code
-@item \\
-A literal backslash.
-
-@item \a
-The ``alert'' character; usually the ASCII BEL character.
-
-@item \b
-Backspace.
-
-@item \f
-Formfeed.
-
-@item \n
-Newline.
-
-@item \r
-Carriage return.
-
-@item \t
-Horizontal tab.
-
-@item \v
-Vertical tab.
-
-@item \x@var{hex digits}
-The character represented by the string of hexadecimal digits following
-the @samp{\x}.  As in @sc{ansi} C, all following hexadecimal digits are
-considered part of the escape sequence.  (This feature should tell us
-something about language design by committee.)  E.g., @code{"\x1B"} is a
-string containing the ASCII ESC (escape) character.  (The @samp{\x}
-escape sequence is not in @sc{posix} @code{awk}.)
-
-@item \@var{ddd}
-The character represented by the 1-, 2-, or 3-digit sequence of octal
-digits.  Thus, @code{"\033"} is also a string containing the ASCII ESC
-(escape) character.
-
-@item \@var{c}
-The literal character @var{c}.
-@end table
-
-The escape sequences may also be used inside constant regular expressions
-(e.g., the regexp @code{@w{/[@ \t\f\n\r\v]/}} matches whitespace
-characters).@refill
-
-@xref{Constants, ,Constant Expressions}.
-
-@node Functions Summary, Historical Features, Rules Summary, Gawk Summary
-@appendixsec Functions
-
-Functions in @code{awk} are defined as follows:
-
-@example
-function @var{name}(@var{parameter list}) @{ @var{statements} @}
-@end example
-
-Actual parameters supplied in the function call are used to instantiate
-the formal parameters declared in the function.  Arrays are passed by
-reference, other variables are passed by value.
-
-If there are fewer arguments passed than there are names in @var{parameter-list},
-the extra names are given the null string as value.  Extra names have the
-effect of local variables.
-
-The open-parenthesis in a function call of a user-defined function must
-immediately follow the function name, without any intervening white space.
-This is to avoid a syntactic ambiguity with the concatenation operator.
-
-The word @code{func} may be used in place of @code{function} (but not in
-@sc{posix} @code{awk}).
-
-Use the @code{return} statement to return a value from a function.
-
-@xref{User-defined, ,User-defined Functions}, for a more complete description.
-
-@node Historical Features,  , Functions Summary, Gawk Summary
-@appendixsec Historical Features
-
-There are two features of historical @code{awk} implementations that
-@code{gawk} supports.  First, it is possible to call the @code{length}
-built-in function not only with no arguments, but even without parentheses!
-
-@example
-a = length
-@end example
-
-@noindent
-is the same as either of
-
-@example
-a = length()
-a = length($0)
-@end example
-
-@noindent
-This feature is marked as ``deprecated'' in the @sc{posix} standard, and
-@code{gawk} will issue a warning about its use if @samp{-W lint} is
-specified on the command line.
-
-The other feature is the use of the @code{continue} statement outside the
-body of a @code{while}, @code{for}, or @code{do} loop.  Traditional
-@code{awk} implementations have treated such usage as equivalent to the
-@code{next} statement.  @code{gawk} will support this usage if @samp{-W posix}
-has not been specified.
-
-@node Sample Program, Bugs, Gawk Summary, Top
-@appendix Sample Program
-
-The following example is a complete @code{awk} program, which prints
-the number of occurrences of each word in its input.  It illustrates the
-associative nature of @code{awk} arrays by using strings as subscripts.  It
-also demonstrates the @samp{for @var{x} in @var{array}} construction.
-Finally, it shows how @code{awk} can be used in conjunction with other
-utility programs to do a useful task of some complexity with a minimum of
-effort.  Some explanations follow the program listing.@refill
-
-@example
-awk '
-# Print list of word frequencies
-@{
-    for (i = 1; i <= NF; i++)
-        freq[$i]++
-@}
-
-END @{
-    for (word in freq)
-        printf "%s\t%d\n", word, freq[word]
-@}'
-@end example
-
-The first thing to notice about this program is that it has two rules.  The
-first rule, because it has an empty pattern, is executed on every line of
-the input.  It uses @code{awk}'s field-accessing mechanism
-(@pxref{Fields, ,Examining Fields}) to pick out the individual words from
-the line, and the built-in variable @code{NF} (@pxref{Built-in Variables})
-to know how many fields are available.@refill
-
-For each input word, an element of the array @code{freq} is incremented to
-reflect that the word has been seen an additional time.@refill
-
-The second rule, because it has the pattern @code{END}, is not executed
-until the input has been exhausted.  It prints out the contents of the
-@code{freq} table that has been built up inside the first action.@refill
-
-Note that this program has several problems that would prevent it from being
-useful by itself on real text files:@refill
-
-@itemize @bullet
-@item
-Words are detected using the @code{awk} convention that fields are
-separated by whitespace and that other characters in the input (except
-newlines) don't have any special meaning to @code{awk}.  This means that
-punctuation characters count as part of words.@refill
-
-@item
-The @code{awk} language considers upper and lower case characters to be
-distinct.  Therefore, @samp{foo} and @samp{Foo} are not treated by this
-program as the same word.  This is undesirable since in normal text, words
-are capitalized if they begin sentences, and a frequency analyzer should not
-be sensitive to that.@refill
-
-@item
-The output does not come out in any useful order.  You're more likely to be
-interested in which words occur most frequently, or having an alphabetized
-table of how frequently each word occurs.@refill
-@end itemize
-
-The way to solve these problems is to use some of the more advanced
-features of the @code{awk} language.  First, we use @code{tolower} to remove
-case distinctions.  Next, we use @code{gsub} to remove punctuation
-characters.  Finally, we use the system @code{sort} utility to process the
-output of the @code{awk} script.  First, here is the new version of
-the program:@refill
-
-@example
-awk '
-# Print list of word frequencies
-@{
-    $0 = tolower($0)    # remove case distinctions
-    gsub(/[^a-z0-9_ \t]/, "", $0)  # remove punctuation
-    for (i = 1; i <= NF; i++)
-        freq[$i]++
-@}
-
-END @{
-    for (word in freq)
-        printf "%s\t%d\n", word, freq[word]
-@}'
-@end example
-
-Assuming we have saved this program in a file named @file{frequency.awk},
-and that the data is in @file{file1}, the following pipeline
-
-@example
-awk -f frequency.awk file1 | sort +1 -nr
-@end example
-
-@noindent
-produces a table of the words appearing in @file{file1} in order of
-decreasing frequency.
-
-The @code{awk} program suitably massages the data and produces a word
-frequency table, which is not ordered.
-
-The @code{awk} script's output is then sorted by the @code{sort} command and
-printed on the terminal.  The options given to @code{sort} in this example
-specify to sort using the second field of each input line (skipping one field),
-that the sort keys should be treated as numeric quantities (otherwise
-@samp{15} would come before @samp{5}), and that the sorting should be done
-in descending (reverse) order.@refill
-
-We could have even done the @code{sort} from within the program, by
-changing the @code{END} action to:
-
-@example
-END @{
-    sort = "sort +1 -nr"
-    for (word in freq)
-        printf "%s\t%d\n", word, freq[word] | sort
-    close(sort)
-@}'
-@end example
-
-See the general operating system documentation for more information on how
-to use the @code{sort} command.@refill
-
-@ignore
-@strong{ADR: I have some more substantial programs courtesy of Rick Adams
-at UUNET.  I am planning on incorporating those either in addition to or
-instead of this program.}
-
-@strong{I would also like to incorporate the general @code{translate}
-function that I have written.}
-
-@strong{I have a ton of other sample programs to include too.}
-@end ignore
-
-@node Bugs, Notes, Sample Program, Top
-@appendix Reporting Problems and Bugs
-
-@c This chapter stolen shamelessly from the GNU m4 manual.
-@c This chapter has been unshamelessly altered to emulate changes made to
-@c make.texi from whence it was originally shamelessly stolen! :-} --mew
-
-If you have problems with @code{gawk} or think that you have found a bug,
-please report it to the developers; we cannot promise to do anything
-but we might well want to fix it.
-
-Before reporting a bug, make sure you have actually found a real bug.
-Carefully reread the documentation and see if it really says you can do
-what you're trying to do.  If it's not clear whether you should be able
-to do something or not, report that too; it's a bug in the documentation!
-
-Before reporting a bug or trying to fix it yourself, try to isolate it
-to the smallest possible @code{awk} program and input data file that
-reproduces the problem.  Then send us the program and data file,
-some idea of what kind of Unix system you're using, and the exact results
-@code{gawk} gave you.  Also say what you expected to occur; this will help
-us decide whether the problem was really in the documentation.
-
-Once you have a precise problem, send e-mail to (Internet)
-@samp{bug-gnu-utils@@prep.ai.mit.edu} or (UUCP)
-@samp{mit-eddie!prep.ai.mit.edu!bug-gnu-utils}.  Please include the
-version number of @code{gawk} you are using.  You can get this information
-with the command @samp{gawk -W version '@{@}' /dev/null}.
-You should send carbon copies of your mail to David Trueman at
-@samp{david@@cs.dal.ca}, and to Arnold Robbins, who can be reached at
-@samp{arnold@@skeeve.atl.ga.us}.  David is most likely to fix code
-problems, while Arnold is most likely to fix documentation problems.@refill
-
-Non-bug suggestions are always welcome as well.  If you have questions
-about things that are unclear in the documentation or are just obscure
-features, ask Arnold Robbins; he will try to help you out, although he
-may not have the time to fix the problem.  You can send him electronic mail at the Internet address
-above.
-
-If you find bugs in one of the non-Unix ports of @code{gawk}, please send
-an electronic mail message to the person who maintains that port.  They
-are listed below, and also in the @file{README} file in the @code{gawk}
-distribution.  Information in the @code{README} file should be considered
-authoritative if it conflicts with this manual.
-
-The people maintaining the non-Unix ports of @code{gawk} are:
-
-@table @asis
-@item MS-DOS
-The port to MS-DOS is maintained by Scott Deifik.
-His electronic mail address is @samp{scottd@@amgen.com}.
-
-@item VMS
-The port to VAX VMS is maintained by Pat Rankin.
-His electronic mail address is @samp{rankin@@eql.caltech.edu}.
-
-@item Atari ST
-The port to the Atari ST is maintained by Michal Jaegermann.
-His electronic mail address is @samp{ntomczak@@vm.ucs.ualberta.ca}.
-
-@end table
-
-If your bug is also reproducible under Unix, please send copies of your
-report to the general GNU bug list, as well as to Arnold Robbins and David
-Trueman, at the addresses listed above.
-
-@node Notes, Glossary, Bugs, Top
-@appendix Implementation Notes
-
-This appendix contains information mainly of interest to implementors and
-maintainers of @code{gawk}.  Everything in it applies specifically to
-@code{gawk}, and not to other implementations.
-
-@menu
-* Compatibility Mode::          How to disable certain @code{gawk} extensions.
-* Future Extensions::           New features we may implement soon.
-* Improvements::                Suggestions for improvements by volunteers.
-@end menu
-
-@node Compatibility Mode, Future Extensions, Notes, Notes
-@appendixsec Downward Compatibility and Debugging
-
-@xref{POSIX/GNU, ,Extensions in @code{gawk} not in POSIX @code{awk}},
-for a summary of the GNU extensions to the @code{awk} language and program.
-All of these features can be turned off by invoking @code{gawk} with the
-@samp{-W compat} option, or with the @samp{-W posix} option.@refill
-
-If @code{gawk} is compiled for debugging with @samp{-DDEBUG}, then there
-is one more option available on the command line:
-
-@table @samp
-@item -W parsedebug
-Print out the parse stack information as the program is being parsed.
-@end table
-
-This option is intended only for serious @code{gawk} developers,
-and not for the casual user.  It probably has not even been compiled into
-your version of @code{gawk}, since it slows down execution.
-
-@node Future Extensions, Improvements, Compatibility Mode, Notes
-@appendixsec Probable Future Extensions
-
-This section briefly lists extensions that indicate the directions we are
-currently considering for @code{gawk}.  The file @file{FUTURES} in the
-@code{gawk} distributions lists these extensions, as well as several others.
-
-@table @asis
-@item @code{RS} as a regexp
-The meaning of @code{RS} may be generalized along the lines of @code{FS}.
-
-@item Control of subprocess environment
-Changes made in @code{gawk} to the array @code{ENVIRON} may be
-propagated to subprocesses run by @code{gawk}.
-
-@item Databases
-It may be possible to map a GDBM/NDBM/SDBM file into an @code{awk} array.
-
-@item Single-character fields
-The null string, @code{""}, as a field separator, will cause field
-splitting and the @code{split} function to separate individual characters.
-Thus, @code{split(a, "abcd", "")} would yield @code{a[1] == "a"},
-@code{a[2] == "b"}, and so on.
-
-@item More @code{lint} warnings
-There are more things that could be checked for portability.
-
-@item @code{RECLEN} variable for fixed length records
-Along with @code{FIELDWIDTHS}, this would speed up the processing of
-fixed-length records.
-
-@item @code{RT} variable to hold the record terminator
-It is occasionally useful to have access to the actual string of
-characters that matched the @code{RS} variable.  The @code{RT}
-variable would hold these characters.
-
-@item A @code{restart} keyword
-After modifying @code{$0}, @code{restart} would restart the pattern
-matching loop, without reading a new record from the input.
-
-@item A @samp{|&} redirection
-The @samp{|&} redirection, in place of @samp{|}, would open a two-way
-pipeline for communication with a sub-process (via @code{getline} and
-@code{print} and @code{printf}).
-
-@item @code{IGNORECASE} affecting all comparisons
-The effects of the @code{IGNORECASE} variable may be generalized to
-all string comparisons, and not just regular expression operations.
-
-@item A way to mix command line source code and library files
-There may be a new option that would make it possible to easily use library
-functions from a program entered on the command line.
-@c probably a @samp{-s} option...
-
-@item GNU-style long options
-We will add GNU-style long options
-to @code{gawk} for compatibility with other GNU programs.
-(For example, @samp{--field-separator=:} would be equivalent to
-@samp{-F:}.)@refill
-
-@c this is @emph{very} long term --- not worth including right now.
-@ignore
-@item The C Comma Operator
-We may add the C comma operator, which takes the form
-@code{@var{expr1},@var{expr2}}.  The first expression is evaluated, and the
-result is thrown away.  The value of the full expression is the value of
-@var{expr2}.@refill
-@end ignore
-@end table
-
-@node Improvements,  , Future Extensions, Notes
-@appendixsec Suggestions for Improvements
-
-Here are some projects that would-be @code{gawk} hackers might like to take
-on.  They vary in size from a few days to a few weeks of programming,
-depending on which one you choose and how fast a programmer you are.  Please
-send any improvements you write to the maintainers at the GNU
-project.@refill
-
-@enumerate
-@item
-Compilation of @code{awk} programs: @code{gawk} uses a Bison (YACC-like)
-parser to convert the script given it into a syntax tree; the syntax
-tree is then executed by a simple recursive evaluator.  This method incurs
-a lot of overhead, since the recursive evaluator performs many procedure
-calls to do even the simplest things.@refill
-
-It should be possible for @code{gawk} to convert the script's parse tree
-into a C program which the user would then compile, using the normal
-C compiler and a special @code{gawk} library to provide all the needed
-functions (regexps, fields, associative arrays, type coercion, and so
-on).@refill
-
-An easier possibility might be for an intermediate phase of @code{awk} to
-convert the parse tree into a linear byte code form like the one used
-in GNU Emacs Lisp.  The recursive evaluator would then be replaced by
-a straight line byte code interpreter that would be intermediate in speed
-between running a compiled program and doing what @code{gawk} does
-now.@refill
-
-This may actually happen for the 3.0 version of @code{gawk}.
-
-@item
-An error message section has not been included in this version of the
-manual.  Perhaps some nice beta testers will document some of the messages
-for the future.
-
-@item
-The programs in the test suite could use documenting in this manual.
-
-@item
-The programs and data files in the manual should be available in
-separate files to facilitate experimentation.
-
-@item
-See the @file{FUTURES} file for more ideas.  Contact us if you would
-seriously like to tackle any of the items listed there.
-@end enumerate
-
-@node Glossary, Index, Notes, Top
-@appendix Glossary
-
-@table @asis
-@item Action
-A series of @code{awk} statements attached to a rule.  If the rule's
-pattern matches an input record, the @code{awk} language executes the
-rule's action.  Actions are always enclosed in curly braces.
-@xref{Actions, ,Overview of Actions}.@refill
-
-@item Amazing @code{awk} Assembler
-Henry Spencer at the University of Toronto wrote a retargetable assembler
-completely as @code{awk} scripts.  It is thousands of lines long, including
-machine descriptions for several 8-bit microcomputers.
-@c It is distributed with @code{gawk} (as part of the test suite) and
-It is a good example of a
-program that would have been better written in another language.@refill
-
-@item @sc{ansi}
-The American National Standards Institute.  This organization produces
-many standards, among them the standard for the C programming language.
-
-@item Assignment
-An @code{awk} expression that changes the value of some @code{awk}
-variable or data object.  An object that you can assign to is called an
-@dfn{lvalue}.  @xref{Assignment Ops, ,Assignment Expressions}.@refill
-
-@item @code{awk} Language
-The language in which @code{awk} programs are written.
-
-@item @code{awk} Program
-An @code{awk} program consists of a series of @dfn{patterns} and
-@dfn{actions}, collectively known as @dfn{rules}.  For each input record
-given to the program, the program's rules are all processed in turn.
-@code{awk} programs may also contain function definitions.@refill
-
-@item @code{awk} Script
-Another name for an @code{awk} program.
-
-@item Built-in Function
-The @code{awk} language provides built-in functions that perform various
-numerical, time stamp related, and string computations.  Examples are
-@code{sqrt} (for the square root of a number) and @code{substr} (for a
-substring of a string).  @xref{Built-in, ,Built-in Functions}.@refill
-
-@item Built-in Variable
-@code{ARGC}, @code{ARGIND}, @code{ARGV}, @code{CONVFMT}, @code{ENVIRON},
-@code{ERRNO}, @code{FIELDWIDTHS}, @code{FILENAME}, @code{FNR}, @code{FS},
-@code{IGNORECASE}, @code{NF}, @code{NR}, @code{OFMT}, @code{OFS}, @code{ORS},
-@code{RLENGTH}, @code{RSTART}, @code{RS}, and @code{SUBSEP},
-are the variables that have special
-meaning to @code{awk}.  Changing some of them affects @code{awk}'s running
-environment.  @xref{Built-in Variables}.@refill
-
-@item Braces
-See ``Curly Braces.''
-
-@item C
-The system programming language that most GNU software is written in.  The
-@code{awk} programming language has C-like syntax, and this manual
-points out similarities between @code{awk} and C when appropriate.@refill
-
-@item CHEM
-A preprocessor for @code{pic} that reads descriptions of molecules
-and produces @code{pic} input for drawing them.  It was written by
-Brian Kernighan, and is available from @code{netlib@@research.att.com}.@refill
-
-@item Compound Statement
-A series of @code{awk} statements, enclosed in curly braces.  Compound
-statements may be nested.
-@xref{Statements, ,Control Statements in Actions}.@refill
-
-@item Concatenation
-Concatenating two strings means sticking them together, one after another,
-giving a new string.  For example, the string @samp{foo} concatenated with
-the string @samp{bar} gives the string @samp{foobar}.
-@xref{Concatenation, ,String Concatenation}.@refill
-
-@item Conditional Expression
-An expression using the @samp{?:} ternary operator, such as
-@code{@var{expr1} ? @var{expr2} : @var{expr3}}.  The expression
-@var{expr1} is evaluated; if the result is true, the value of the whole
-expression is the value of @var{expr2} otherwise the value is
-@var{expr3}.  In either case, only one of @var{expr2} and @var{expr3}
-is evaluated.  @xref{Conditional Exp, ,Conditional Expressions}.@refill
-
-@item Constant Regular Expression
-A constant regular expression is a regular expression written within
-slashes, such as @samp{/foo/}.  This regular expression is chosen
-when you write the @code{awk} program, and cannot be changed doing
-its execution.  @xref{Regexp Usage, ,How to Use Regular Expressions}.
-
-@item Comparison Expression
-A relation that is either true or false, such as @code{(a < b)}.
-Comparison expressions are used in @code{if}, @code{while}, and @code{for}
-statements, and in patterns to select which input records to process.
-@xref{Comparison Ops, ,Comparison Expressions}.@refill
-
-@item Curly Braces
-The characters @samp{@{} and @samp{@}}.  Curly braces are used in
-@code{awk} for delimiting actions, compound statements, and function
-bodies.@refill
-
-@item Data Objects
-These are numbers and strings of characters.  Numbers are converted into
-strings and vice versa, as needed.
-@xref{Conversion, ,Conversion of Strings and Numbers}.@refill
-
-@item Dynamic Regular Expression
-A dynamic regular expression is a regular expression written as an
-ordinary expression.  It could be a string constant, such as
-@code{"foo"}, but it may also be an expression whose value may vary.
-@xref{Regexp Usage, ,How to Use Regular Expressions}.
-
-@item Escape Sequences
-A special sequence of characters used for describing nonprinting
-characters, such as @samp{\n} for newline, or @samp{\033} for the ASCII
-ESC (escape) character.  @xref{Constants, ,Constant Expressions}.
-
-@item Field
-When @code{awk} reads an input record, it splits the record into pieces
-separated by whitespace (or by a separator regexp which you can
-change by setting the built-in variable @code{FS}).  Such pieces are
-called fields.  If the pieces are of fixed length, you can use the built-in
-variable @code{FIELDWIDTHS} to describe their lengths.
-@xref{Records, ,How Input is Split into Records}.@refill
-
-@item Format
-Format strings are used to control the appearance of output in the
-@code{printf} statement.  Also, data conversions from numbers to strings
-are controlled by the format string contained in the built-in variable
-@code{CONVFMT}.  @xref{Control Letters, ,Format-Control Letters}.@refill
-
-@item Function
-A specialized group of statements often used to encapsulate general
-or program-specific tasks.  @code{awk} has a number of built-in
-functions, and also allows you to define your own.
-@xref{Built-in, ,Built-in Functions}.
-Also, see @ref{User-defined, ,User-defined Functions}.@refill
-
-@item @code{gawk}
-The GNU implementation of @code{awk}.
-
-@item GNU
-``GNU's not Unix''.  An on-going project of the Free Software Foundation
-to create a complete, freely distributable, @sc{posix}-compliant computing
-environment.
-
-@item Input Record
-A single chunk of data read in by @code{awk}.  Usually, an @code{awk} input
-record consists of one line of text.
-@xref{Records, ,How Input is Split into Records}.@refill
-
-@item Keyword
-In the @code{awk} language, a keyword is a word that has special
-meaning.  Keywords are reserved and may not be used as variable names.
-
-@code{awk}'s keywords are:
-@code{if},
-@code{else},
-@code{while},
-@code{do@dots{}while},
-@code{for},
-@code{for@dots{}in},
-@code{break},
-@code{continue},
-@code{delete},
-@code{next},
-@code{function},
-@code{func},
-and @code{exit}.@refill
-
-@item Lvalue
-An expression that can appear on the left side of an assignment
-operator.  In most languages, lvalues can be variables or array
-elements.  In @code{awk}, a field designator can also be used as an
-lvalue.@refill
-
-@item Number
-A numeric valued data object.  The @code{gawk} implementation uses double
-precision floating point to represent numbers.@refill
-
-@item Pattern
-Patterns tell @code{awk} which input records are interesting to which
-rules.
-
-A pattern is an arbitrary conditional expression against which input is
-tested.  If the condition is satisfied, the pattern is said to @dfn{match}
-the input record.  A typical pattern might compare the input record against
-a regular expression.  @xref{Patterns}.@refill
-
-@item @sc{posix}
-The name for a series of standards being developed by the @sc{ieee}
-that specify a Portable Operating System interface.  The ``IX'' denotes
-the Unix heritage of these standards.  The main standard of interest for
-@code{awk} users is P1003.2, the Command Language and Utilities standard.
-
-@item Range (of input lines)
-A sequence of consecutive lines from the input file.  A pattern
-can specify ranges of input lines for @code{awk} to process, or it can
-specify single lines.  @xref{Patterns}.@refill
-
-@item Recursion
-When a function calls itself, either directly or indirectly.
-If this isn't clear, refer to the entry for ``recursion.''
-
-@item Redirection
-Redirection means performing input from other than the standard input
-stream, or output to other than the standard output stream.
-
-You can redirect the output of the @code{print} and @code{printf} statements
-to a file or a system command, using the @samp{>}, @samp{>>}, and @samp{|}
-operators.  You can redirect input to the @code{getline} statement using
-the @samp{<} and @samp{|} operators.
-@xref{Redirection, ,Redirecting Output of @code{print} and @code{printf}}.@refill
-
-@item Regular Expression
-See ``regexp.''
-
-@item Regexp
-Short for @dfn{regular expression}.  A regexp is a pattern that denotes a
-set of strings, possibly an infinite set.  For example, the regexp
-@samp{R.*xp} matches any string starting with the letter @samp{R}
-and ending with the letters @samp{xp}.  In @code{awk}, regexps are
-used in patterns and in conditional expressions.  Regexps may contain
-escape sequences.  @xref{Regexp, ,Regular Expressions as Patterns}.@refill
-
-@item Rule
-A segment of an @code{awk} program, that specifies how to process single
-input records.  A rule consists of a @dfn{pattern} and an @dfn{action}.
-@code{awk} reads an input record; then, for each rule, if the input record
-satisfies the rule's pattern, @code{awk} executes the rule's action.
-Otherwise, the rule does nothing for that input record.@refill
-
-@item Side Effect
-A side effect occurs when an expression has an effect aside from merely
-producing a value.  Assignment expressions, increment expressions and
-function calls have side effects.  @xref{Assignment Ops, ,Assignment Expressions}.
-
-@item Special File
-A file name interpreted internally by @code{gawk}, instead of being handed
-directly to the underlying operating system.  For example, @file{/dev/stdin}.
-@xref{Special Files, ,Standard I/O Streams}.
-
-@item Stream Editor
-A program that reads records from an input stream and processes them one
-or more at a time.  This is in contrast with batch programs, which may
-expect to read their input files in entirety before starting to do
-anything, and with interactive programs, which require input from the
-user.@refill
-
-@item String
-A datum consisting of a sequence of characters, such as @samp{I am a
-string}.  Constant strings are written with double-quotes in the
-@code{awk} language, and may contain escape sequences.
-@xref{Constants, ,Constant Expressions}.
-
-@item Whitespace
-A sequence of blank or tab characters occurring inside an input record or a
-string.@refill
-@end table
-
-@node Index,  , Glossary, Top
-@unnumbered Index
-@printindex cp
-
-@summarycontents
-@contents
-@bye
-
-Unresolved Issues:
-------------------
-1. From: ntomczak@vm.ucs.ualberta.ca (Michal Jaegermann)
-   Examples of usage tend to suggest that /../ and ".." delimiters
-   can be used for regular expressions, even if definition is consistently
-   using /../.  I am not sure what the real rules are and in particular
-   what of the following is a bug and what is a feature:
-   # This program matches everything
-      '"\(" { print }'
-   # This one complains about mismatched parenthesis
-      '$0 ~ "\(" { print }'
-   # This one behaves in an expected manner
-      '/\(/ { print }'
-   You may also try to use "\(" as an argument to match() to see what
-   will happen.
-
-2. From ADR.
-
-   The posix (and original Unix!) notion of awk values as both number
-   and string values needs to be put into the manual.  This involves
-   major and minor rewrites of most of the manual, but should help in
-   clarifying many of the weirder points of the language.
-
-3. From ADR.
-
-   The manual should be reorganized.  Expressions should be introduced
-   early, building up to regexps as expressions, and from there to their
-   use as patterns and then in actions.  Built-in vars should come earlier
-   in the manual too.  The 'expert info' sections marked with comments
-   should get their own sections or subsections with nodes and titles.
-   The manual should be gone over thoroughly for indexing.
-
-4. From ADR.
-
-   Robert J. Chassell points out that awk programs should have some indication
-   of how to use them.  It would be useful to perhaps have a "programming
-   style" section of the manual that would include this and other tips.
-
-5. From ADR in response to moraes@uunet.ca
-   (This would make the beginnings of a good "puzzles" section...)
-
-   Date: Mon, 2 Dec 91 10:08:05 EST
-   From: gatech!cc!arnold (Arnold Robbins)
-   To: cs.dal.ca!david, uunet.ca!moraes
-   Subject: redirecting to /dev/stderr
-   Cc: skeeve!arnold, boeing.com!brennan, research.att.com!bwk
-   
-   In 2.13.3 the following program no longer dumps core:
-   
-   	BEGIN { print "hello" > /dev/stderr ; exit(1) }
-   
-   Instead, it creates a file named `0' with the word `hello' in it. AWK
-   semantics strikes again.  The meaning of the statement is
-   
-   		print "hello" > (($0 ~ /dev/) stderr)
-   
-   /dev/ tests $0 for the pattern `dev'.  This yields a 0.  The variable stderr,
-   having never been used, has a null string in it.  The concatenation yields
-   a string value of "0" which is used as the file name.  Sigh.
-   
-   I think with some more time I can come up with a decent fix, but it will
-   probably only print a diagnostic with -Wlint.
-   
-   Arnold
-
diff --git a/gnu/usr.bin/ptx/ptx.info b/gnu/usr.bin/ptx/ptx.info
deleted file mode 100644
index 3bbd1bb..0000000
--- a/gnu/usr.bin/ptx/ptx.info
+++ /dev/null
@@ -1,496 +0,0 @@
-This is Info file ptx.info, produced by Makeinfo-1.47 from the input
-file ./ptx.texinfo.
-
-   This file documents the `ptx' command, which has the purpose of
-generated permuted indices for group of files.
-
-   Copyright (C) 1990, 1991, 1993 by the Free Software Foundation, Inc.
-
-   Permission is granted to make and distribute verbatim copies of this
-manual provided the copyright notice and this permission notice are
-preserved on all copies.
-
-   Permission is granted to copy and distribute modified versions of
-this manual under the conditions for verbatim copying, provided that
-the entire resulting derived work is distributed under the terms of a
-permission notice identical to this one.
-
-   Permission is granted to copy and distribute translations of this
-manual into another language, under the above conditions for modified
-versions, except that this permission notice may be stated in a
-translation approved by the Foundation.
-
-
-File: ptx.info,  Node: Top,  Next: Invoking ptx,  Prev: (dir),  Up: (dir)
-
-Introduction
-************
-
-   This is the 0.3 beta release of `ptx', the GNU version of a permuted
-index generator.  This software has the main goal of providing a
-replacement for the traditional `ptx' as found on System V machines,
-able to handle small files quickly, while providing a platform for more
-development.
-
-   This version reimplements and extends traditional `ptx'.  Among
-other things, it can produce a readable "KWIC" (keywords in their
-context) without the need of `nroff', there is also an option to
-produce TeX compatible output.  This version does not handle huge input
-files, that is, those files which do not fit in memory all at once.
-
-   *Please note* that an overall renaming of all options is
-foreseeable.  In fact, GNU ptx specifications are not frozen yet.
-
-* Menu:
-
-* Invoking ptx::                How to use this program
-* Compatibility::               The GNU extensions to `ptx'
-
- -- The Detailed Node Listing --
-
-How to use this program
-
-* General options::             Options which affect general program behaviour.
-* Charset selection::           Underlying character set considerations.
-* Input processing::            Input fields, contexts, and keyword selection.
-* Output formatting::           Types of output format, and sizing the fields.
-
-
-File: ptx.info,  Node: Invoking ptx,  Next: Compatibility,  Prev: Top,  Up: Top
-
-How to use this program
-***********************
-
-   This tool reads a text file and essentially produces a permuted
-index, with each keyword in its context.  The calling sketch is one of:
-
-     ptx [OPTION ...] [FILE ...]
-
-   or:
-
-     ptx -G [OPTION ...] [INPUT [OUTPUT]]
-
-   The `-G' (or its equivalent: `--traditional') option disables all
-GNU extensions and revert to traditional mode, thus introducing some
-limitations, and changes several of the program's default option values.
-When `-G' is not specified, GNU extensions are always enabled.  GNU
-extensions to `ptx' are documented wherever appropriate in this
-document.  See *Note Compatibility:: for an explicit list of them.
-
-   Individual options are explained later in this document.
-
-   When GNU extensions are enabled, there may be zero, one or several
-FILE after the options.  If there is no FILE, the program reads the
-standard input.  If there is one or several FILE, they give the name of
-input files which are all read in turn, as if all the input files were
-concatenated.  However, there is a full contextual break between each
-file and, when automatic referencing is requested, file names and line
-numbers refer to individual text input files.  In all cases, the
-program produces the permuted index onto the standard output.
-
-   When GNU extensions are *not* enabled, that is, when the program
-operates in traditional mode, there may be zero, one or two parameters
-besides the options.  If there is no parameters, the program reads the
-standard input and produces the permuted index onto the standard output.
-If there is only one parameter, it names the text INPUT to be read
-instead of the standard input.  If two parameters are given, they give
-respectively the name of the INPUT file to read and the name of the
-OUTPUT file to produce.  *Be very careful* to note that, in this case,
-the contents of file given by the second parameter is destroyed.  This
-behaviour is dictated only by System V `ptx' compatibility, because GNU
-Standards discourage output parameters not introduced by an option.
-
-   Note that for *any* file named as the value of an option or as an
-input text file, a single dash `-' may be used, in which case standard
-input is assumed.  However, it would not make sense to use this
-convention more than once per program invocation.
-
-* Menu:
-
-* General options::             Options which affect general program behaviour.
-* Charset selection::           Underlying character set considerations.
-* Input processing::            Input fields, contexts, and keyword selection.
-* Output formatting::           Types of output format, and sizing the fields.
-
-
-File: ptx.info,  Node: General options,  Next: Charset selection,  Prev: Invoking ptx,  Up: Invoking ptx
-
-General options
-===============
-
-`-C'
-`--copyright'
-     Prints a short note about the Copyright and copying conditions,
-     then exit without further processing.
-
-`-G'
-`--traditional'
-     As already explained, this option disables all GNU extensions to
-     `ptx' and switch to traditional mode.
-
-`--help'
-     Prints a short help on standard output, then exit without further
-     processing.
-
-`--version'
-     Prints the program verison on standard output, then exit without
-     further processing.
-
-
-File: ptx.info,  Node: Charset selection,  Next: Input processing,  Prev: General options,  Up: Invoking ptx
-
-Charset selection
-=================
-
-   As it is setup now, the program assumes that the input file is coded
-using 8-bit ISO 8859-1 code, also known as Latin-1 character set,
-*unless* if it is compiled for MS-DOS, in which case it uses the
-character set of the IBM-PC.  (GNU `ptx' is not known to work on
-smaller MS-DOS machines anymore.)  Compared to 7-bit ASCII, the set of
-characters which are letters is then different, this fact alters the
-behaviour of regular expression matching.  Thus, the default regular
-expression for a keyword allows foreign or diacriticized letters.
-Keyword sorting, however, is still crude; it obeys the underlying
-character set ordering quite blindly.
-
-`-f'
-`--ignore-case'
-     Fold lower case letters to upper case for sorting.
-
-
-File: ptx.info,  Node: Input processing,  Next: Output formatting,  Prev: Charset selection,  Up: Invoking ptx
-
-Word selection
-==============
-
-`-b FILE'
-`--break-file=FILE'
-     This option is an alternative way to option `-W' for describing
-     which characters make up words.  This option introduces the name
-     of a file which contains a list of characters which can*not* be
-     part of one word, this file is called the "Break file".  Any
-     character which is not part of the Break file is a word
-     constituent.  If both options `-b' and `-W' are specified, then
-     `-W' has precedence and `-b' is ignored.
-
-     When GNU extensions are enabled, the only way to avoid newline as a
-     break character is to write all the break characters in the file
-     with no newline at all, not even at the end of the file.  When GNU
-     extensions are disabled, spaces, tabs and newlines are always
-     considered as break characters even if not included in the Break
-     file.
-
-`-i FILE'
-`--ignore-file=FILE'
-     The file associated with this option contains a list of words
-     which will never be taken as keywords in concordance output.  It
-     is called the "Ignore file".  The file contains exactly one word
-     in each line; the end of line separation of words is not subject
-     to the value of the `-S' option.
-
-     There is a default Ignore file used by `ptx' when this option is
-     not specified, usually found in `/usr/local/lib/eign' if this has
-     not been changed at installation time.  If you want to deactivate
-     the default Ignore file, specify `/dev/null' instead.
-
-`-o FILE'
-`--only-file=FILE'
-     The file associated with this option contains a list of words
-     which will be retained in concordance output, any word not
-     mentioned in this file is ignored.  The file is called the "Only
-     file".  The file contains exactly one word in each line; the end
-     of line separation of words is not subject to the value of the
-     `-S' option.
-
-     There is no default for the Only file.  In the case there are both
-     an Only file and an Ignore file, a word will be subject to be a
-     keyword only if it is given in the Only file and not given in the
-     Ignore file.
-
-`-r'
-`--references'
-     On each input line, the leading sequence of non white characters
-     will be taken to be a reference that has the purpose of
-     identifying this input line on the produced permuted index.  See
-     *Note Output formatting:: for more information about reference
-     production.  Using this option change the default value for option
-     `-S'.
-
-     Using this option, the program does not try very hard to remove
-     references from contexts in output, but it succeeds in doing so
-     *when* the context ends exactly at the newline.  If option `-r' is
-     used with `-S' default value, or when GNU extensions are disabled,
-     this condition is always met and references are completely
-     excluded from the output contexts.
-
-`-S REGEXP'
-`--sentence-regexp=REGEXP'
-     This option selects which regular expression will describe the end
-     of a line or the end of a sentence.  In fact, there is other
-     distinction between end of lines or end of sentences than the
-     effect of this regular expression, and input line boundaries have
-     no special significance outside this option.  By default, when GNU
-     extensions are enabled and if `-r' option is not used, end of
-     sentences are used.  In this case, the precise REGEX is imported
-     from GNU emacs:
-
-          [.?!][]\"')}]*\\($\\|\t\\|  \\)[ \t\n]*
-
-     Whenever GNU extensions are disabled or if `-r' option is used, end
-     of lines are used; in this case, the default REGEXP is just:
-
-          \n
-
-     Using an empty REGEXP is equivalent to completely disabling end of
-     line or end of sentence recognition.  In this case, the whole file
-     is considered to be a single big line or sentence.  The user might
-     want to disallow all truncation flag generation as well, through
-     option `-F ""'. *Note Syntax of Regular Expressions:
-     (emacs)Regexps.
-
-     When the keywords happen to be near the beginning of the input
-     line or sentence, this often creates an unused area at the
-     beginning of the output context line; when the keywords happen to
-     be near the end of the input line or sentence, this often creates
-     an unused area at the end of the output context line.  The program
-     tries to fill those unused areas by wrapping around context in
-     them; the tail of the input line or sentence is used to fill the
-     unused area on the left of the output line; the head of the input
-     line or sentence is used to fill the unused area on the right of
-     the output line.
-
-     As a matter of convenience to the user, many usual backslashed
-     escape sequences, as found in the C language, are recognized and
-     converted to the corresponding characters by `ptx' itself.
-
-`-W REGEXP'
-`--word-regexp=REGEXP'
-     This option selects which regular expression will describe each
-     keyword. By default, if GNU extensions are enabled, a word is a
-     sequence of letters; the REGEXP used is `\w+'.  When GNU
-     extensions are disabled, a word is by default anything which ends
-     with a space, a tab or a newline; the REGEXP used is `[^ \t\n]+'.
-
-     An empty REGEXP is equivalent to not using this option, letting the
-     default dive in.  *Note Syntax of Regular Expressions:
-     (emacs)Regexps.
-
-     As a matter of convenience to the user, many usual backslashed
-     escape sequences, as found in the C language, are recognized and
-     converted to the corresponding characters by `ptx' itself.
-
-
-File: ptx.info,  Node: Output formatting,  Prev: Input processing,  Up: Invoking ptx
-
-Output formatting
-=================
-
-   Output format is mainly controlled by `-O' and `-T' options,
-described in the table below.  When neither `-O' nor `-T' is selected,
-and if GNU extensions are enabled, the program choose an output format
-suited for a dumb terminal.  Each keyword occurrence is output to the
-center of one line, surrounded by its left and right contexts.  Each
-field is properly justified, so the concordance output could readily be
-observed.  As a special feature, if automatic references are selected
-by option `-A' and are output before the left context, that is, if
-option `-R' is *not* selected, then a colon is added after the
-reference; this nicely interfaces with GNU Emacs `next-error'
-processing.  In this default output format, each white space character,
-like newline and tab, is merely changed to exactly one space, with no
-special attempt to compress consecutive spaces.  This might change in
-the future.  Except for those white space characters, every other
-character of the underlying set of 256 characters is transmitted
-verbatim.
-
-   Output format is further controlled by the following options.
-
-`-g NUMBER'
-`--gap-size=NUMBER'
-     Select the size of the minimum white gap between the fields on the
-     output line.
-
-`-w NUMBER'
-`--width=NUMBER'
-     Select the output maximum width of each final line.  If references
-     are used, they are included or excluded from the output maximum
-     width depending on the value of option `-R'.  If this option is not
-     selected, that is, when references are output before the left
-     context, the output maximum width takes into account the maximum
-     length of all references.  If this options is selected, that is,
-     when references are output after the right context, the output
-     maximum width does not take into account the space taken by
-     references, nor the gap that precedes them.
-
-`-A'
-`--auto-reference'
-     Select automatic references.  Each input line will have an
-     automatic reference made up of the file name and the line ordinal,
-     with a single colon between them.  However, the file name will be
-     empty when standard input is being read.  If both `-A' and `-r'
-     are selected, then the input reference is still read and skipped,
-     but the automatic reference is used at output time, overriding the
-     input reference.
-
-`-R'
-`--right-side-refs'
-     In default output format, when option `-R' is not used, any
-     reference produced by the effect of options `-r' or `-A' are given
-     to the far right of output lines, after the right context.  In
-     default output format, when option `-R' is specified, references
-     are rather given to the beginning of each output line, before the
-     left context.  For any other output format, option `-R' is almost
-     ignored, except for the fact that the width of references is *not*
-     taken into account in total output width given by `-w' whenever
-     `-R' is selected.
-
-     This option is automatically selected whenever GNU extensions are
-     disabled.
-
-`-F STRING'
-`--flac-truncation=STRING'
-     This option will request that any truncation in the output be
-     reported using the string STRING.  Most output fields
-     theoretically extend towards the beginning or the end of the
-     current line, or current sentence, as selected with option `-S'. 
-     But there is a maximum allowed output line width, changeable
-     through option `-w', which is further divided into space for
-     various output fields.  When a field has to be truncated because
-     cannot extend until the beginning or the end of the current line
-     to fit in the, then a truncation occurs.  By default, the string
-     used is a single slash, as in `-F /'.
-
-     STRING may have more than one character, as in `-F ...'. Also, in
-     the particular case STRING is empty (`-F ""'), truncation flagging
-     is disabled, and no truncation marks are appended in this case.
-
-     As a matter of convenience to the user, many usual backslashed
-     escape sequences, as found in the C language, are recognized and
-     converted to the corresponding characters by `ptx' itself.
-
-`-M STRING'
-`--macro-name=STRING'
-     Select another STRING to be used instead of `xx', while generating
-     output suitable for `nroff', `troff' or TeX.
-
-`-O'
-`--format=roff'
-     Choose an output format suitable for `nroff' or `troff'
-     processing.  Each output line will look like:
-
-          .xx "TAIL" "BEFORE" "KEYWORD_AND_AFTER" "HEAD" "REF"
-
-     so it will be possible to write an `.xx' roff macro to take care of
-     the output typesetting.  This is the default output format when GNU
-     extensions are disabled.  Option `-M' might be used to change `xx'
-     to another macro name.
-
-     In this output format, each non-graphical character, like newline
-     and tab, is merely changed to exactly one space, with no special
-     attempt to compress consecutive spaces.  Each quote character: `"'
-     is doubled so it will be correctly processed by `nroff' or `troff'.
-
-`-T'
-`--format=tex'
-     Choose an output format suitable for TeX processing.  Each output
-     line will look like:
-
-          \xx {TAIL}{BEFORE}{KEYWORD}{AFTER}{HEAD}{REF}
-
-     so it will be possible to write write a `\xx' definition to take
-     care of the output typesetting.  Note that when references are not
-     being produced, that is, neither option `-A' nor option `-r' is
-     selected, the last parameter of each `\xx' call is inhibited.
-     Option `-M' might be used to change `xx' to another macro name.
-
-     In this output format, some special characters, like `$', `%',
-     `&', `#' and `_' are automatically protected with a backslash. 
-     Curly brackets `{', `}' are also protected with a backslash, but
-     also enclosed in a pair of dollar signs to force mathematical
-     mode.  The backslash itself produces the sequence `\backslash{}'. 
-     Circumflex and tilde diacritics produce the sequence `^\{ }' and
-     `~\{ }' respectively.  Other diacriticized characters of the
-     underlying character set produce an appropriate TeX sequence as
-     far as possible.  The other non-graphical characters, like newline
-     and tab, and all others characters which are not part of ASCII,
-     are merely changed to exactly one space, with no special attempt
-     to compress consecutive spaces.  Let me know how to improve this
-     special character processing for TeX.
-
-
-File: ptx.info,  Node: Compatibility,  Prev: Invoking ptx,  Up: Top
-
-The GNU extensions to `ptx'
-***************************
-
-   This version of `ptx' contains a few features which do not exist in
-System V `ptx'.  These extra features are suppressed by using the `-G'
-command line option, unless overridden by other command line options. 
-Some GNU extensions cannot be recovered by overriding, so the simple
-rule is to avoid `-G' if you care about GNU extensions. Here are the
-differences between this program and System V `ptx'.
-
-   * This program can read many input files at once, it always writes
-     the resulting concordance on standard output.  On the other end,
-     System V `ptx' reads only one file and produce the result on
-     standard output or, if a second FILE parameter is given on the
-     command, to that FILE.
-
-     Having output parameters not introduced by options is a quite
-     dangerous practice which GNU avoids as far as possible.  So, for
-     using `ptx' portably between GNU and System V, you should pay
-     attention to always use it with a single input file, and always
-     expect the result on standard output.  You might also want to
-     automatically configure in a `-G' option to `ptx' calls in
-     products using `ptx', if the configurator finds that the installed
-     `ptx' accepts `-G'.
-
-   * The only options available in System V `ptx' are options `-b',
-     `-f', `-g', `-i', `-o', `-r', `-t' and `-w'.  All other options
-     are GNU extensions and are not repeated in this enumeration. 
-     Moreover, some options have a slightly different meaning when GNU
-     extensions are enabled, as explained below.
-
-   * By default, concordance output is not formatted for `troff' or
-     `nroff'.  It is rather formatted for a dumb terminal.  `troff' or
-     `nroff' output may still be selected through option `-O'.
-
-   * Unless `-R' option is used, the maximum reference width is
-     subtracted from the total output line width.  With GNU extensions
-     disabled, width of references is not taken into account in the
-     output line width computations.
-
-   * All 256 characters, even `NUL's, are always read and processed from
-     input file with no adverse effect, even if GNU extensions are
-     disabled. However, System V `ptx' does not accept 8-bit
-     characters, a few control characters are rejected, and the tilda
-     `~' is condemned.
-
-   * Input line length is only limited by available memory, even if GNU
-     extensions are disabled.  However, System V `ptx' processes only
-     the first 200 characters in each line.
-
-   * The break (non-word) characters default to be every character
-     except all letters of the underlying character set, diacriticized
-     or not.  When GNU extensions are disabled, the break characters
-     default to space, tab and newline only.
-
-   * The program makes better use of output line width.  If GNU
-     extensions are disabled, the program rather tries to imitate
-     System V `ptx', but still, there are some slight disposition
-     glitches this program does not completely reproduce.
-
-   * The user can specify both an Ignore file and an Only file.  This
-     is not allowed with System V `ptx'.
-
-
-
-Tag Table:
-Node: Top939
-Node: Invoking ptx2298
-Node: General options5025
-Node: Charset selection5639
-Node: Input processing6514
-Node: Output formatting12205
-Node: Compatibility18737
-
-End Tag Table
diff --git a/gnu/usr.bin/ptx/ptx.texinfo b/gnu/usr.bin/ptx/ptx.texinfo
deleted file mode 100644
index e690c55..0000000
--- a/gnu/usr.bin/ptx/ptx.texinfo
+++ /dev/null
@@ -1,554 +0,0 @@
-\input texinfo @c -*-texinfo-*-
-@c %**start of header
-@setfilename ptx.info
-@settitle GNU @code{ptx} reference manual
-@finalout
-@c %**end of header
-
-@ifinfo
-This file documents the @code{ptx} command, which has the purpose of
-generated permuted indices for group of files.
-
-Copyright (C) 1990, 1991, 1993 by the Free Software Foundation, Inc.
-
-Permission is granted to make and distribute verbatim copies of
-this manual provided the copyright notice and this permission notice
-are preserved on all copies.
-
-@ignore
-Permission is granted to process this file through TeX and print the
-results, provided the printed document carries copying permission
-notice identical to this one except for the removal of this paragraph
-(this paragraph not being relevant to the printed manual).
-
-@end ignore
-Permission is granted to copy and distribute modified versions of this
-manual under the conditions for verbatim copying, provided that the entire
-resulting derived work is distributed under the terms of a permission
-notice identical to this one.
-
-Permission is granted to copy and distribute translations of this manual
-into another language, under the above conditions for modified versions,
-except that this permission notice may be stated in a translation approved
-by the Foundation.
-@end ifinfo
-
-@titlepage
-@title ptx
-@subtitle The GNU permuted indexer
-@subtitle Edition 0.3, for ptx version 0.3
-@subtitle November 1993
-@author by Francois Pinard
-
-@page
-@vskip 0pt plus 1filll
-Copyright @copyright{} 1990, 1991, 1993 Free Software Foundation, Inc.
-
-Permission is granted to make and distribute verbatim copies of
-this manual provided the copyright notice and this permission notice
-are preserved on all copies.
-
-Permission is granted to copy and distribute modified versions of this
-manual under the conditions for verbatim copying, provided that the entire
-resulting derived work is distributed under the terms of a permission
-notice identical to this one.
-
-Permission is granted to copy and distribute translations of this manual
-into another language, under the above conditions for modified versions,
-except that this permission notice may be stated in a translation approved
-by the Foundation.
-@end titlepage
-
-@node Top, Invoking ptx, (dir), (dir)
-@chapter Introduction
-
-This is the 0.3 beta release of @code{ptx}, the GNU version of a
-permuted index generator.  This software has the main goal of providing
-a replacement for the traditional @code{ptx} as found on System V
-machines, able to handle small files quickly, while providing a platform
-for more development.
-
-This version reimplements and extends traditional @code{ptx}.  Among
-other things, it can produce a readable @dfn{KWIC} (keywords in their
-context) without the need of @code{nroff}, there is also an option to
-produce @TeX{} compatible output.  This version does not handle huge
-input files, that is, those files which do not fit in memory all at
-once.
-
-@emph{Please note} that an overall renaming of all options is
-foreseeable.  In fact, GNU ptx specifications are not frozen yet.
-
-@menu
-* Invoking ptx::                How to use this program
-* Compatibility::               The GNU extensions to @code{ptx}
-
- --- The Detailed Node Listing ---
-
-How to use this program
-
-* General options::             Options which affect general program behaviour.
-* Charset selection::           Underlying character set considerations.
-* Input processing::            Input fields, contexts, and keyword selection.
-* Output formatting::           Types of output format, and sizing the fields.
-@end menu
-
-@node Invoking ptx, Compatibility, Top, Top
-@chapter How to use this program
-
-This tool reads a text file and essentially produces a permuted index, with
-each keyword in its context.  The calling sketch is one of:
-
-@example
-ptx [@var{option} @dots{}] [@var{file} @dots{}]
-@end example
-
-or:
-
-@example
-ptx -G [@var{option} @dots{}] [@var{input} [@var{output}]]
-@end example
-
-The @samp{-G} (or its equivalent: @samp{--traditional}) option disables
-all GNU extensions and revert to traditional mode, thus introducing some
-limitations, and changes several of the program's default option values.
-When @samp{-G} is not specified, GNU extensions are always enabled.  GNU
-extensions to @code{ptx} are documented wherever appropriate in this
-document.  See @xref{Compatibility} for an explicit list of them.
-
-Individual options are explained later in this document.
-
-When GNU extensions are enabled, there may be zero, one or several
-@var{file} after the options.  If there is no @var{file}, the program
-reads the standard input.  If there is one or several @var{file}, they
-give the name of input files which are all read in turn, as if all the
-input files were concatenated.  However, there is a full contextual
-break between each file and, when automatic referencing is requested,
-file names and line numbers refer to individual text input files.  In
-all cases, the program produces the permuted index onto the standard
-output.
-  
-When GNU extensions are @emph{not} enabled, that is, when the program
-operates in traditional mode, there may be zero, one or two parameters
-besides the options.  If there is no parameters, the program reads the
-standard input and produces the permuted index onto the standard output.
-If there is only one parameter, it names the text @var{input} to be read
-instead of the standard input.  If two parameters are given, they give
-respectively the name of the @var{input} file to read and the name of
-the @var{output} file to produce.  @emph{Be very careful} to note that,
-in this case, the contents of file given by the second parameter is
-destroyed.  This behaviour is dictated only by System V @code{ptx}
-compatibility, because GNU Standards discourage output parameters not
-introduced by an option.
-
-Note that for @emph{any} file named as the value of an option or as an
-input text file, a single dash @kbd{-} may be used, in which case
-standard input is assumed.  However, it would not make sense to use this
-convention more than once per program invocation.
-
-@menu
-* General options::             Options which affect general program behaviour.
-* Charset selection::           Underlying character set considerations.
-* Input processing::            Input fields, contexts, and keyword selection.
-* Output formatting::           Types of output format, and sizing the fields.
-@end menu
-
-@node General options, Charset selection, Invoking ptx, Invoking ptx
-@section General options
-
-@table @code
-
-@item -C
-@itemx --copyright
-Prints a short note about the Copyright and copying conditions, then
-exit without further processing.
-
-@item -G
-@itemx --traditional
-As already explained, this option disables all GNU extensions to
-@code{ptx} and switch to traditional mode.
-
-@item --help
-Prints a short help on standard output, then exit without further
-processing.
-
-@item --version
-Prints the program verison on standard output, then exit without further
-processing.
-
-@end table
-
-@node Charset selection, Input processing, General options, Invoking ptx
-@section Charset selection
-
-As it is setup now, the program assumes that the input file is coded
-using 8-bit ISO 8859-1 code, also known as Latin-1 character set,
-@emph{unless} if it is compiled for MS-DOS, in which case it uses the
-character set of the IBM-PC.  (GNU @code{ptx} is not known to work on
-smaller MS-DOS machines anymore.)  Compared to 7-bit ASCII, the set of
-characters which are letters is then different, this fact alters the
-behaviour of regular expression matching.  Thus, the default regular
-expression for a keyword allows foreign or diacriticized letters.
-Keyword sorting, however, is still crude; it obeys the underlying
-character set ordering quite blindly.
-
-@table @code
-
-@item -f
-@itemx --ignore-case
-Fold lower case letters to upper case for sorting.
-
-@end table
-
-@node Input processing, Output formatting, Charset selection, Invoking ptx
-@section Word selection
-
-@table @code
-
-@item -b @var{file}
-@item --break-file=@var{file}
-
-This option is an alternative way to option @code{-W} for describing
-which characters make up words.  This option introduces the name of a
-file which contains a list of characters which can@emph{not} be part of
-one word, this file is called the @dfn{Break file}.  Any character which
-is not part of the Break file is a word constituent.  If both options
-@code{-b} and @code{-W} are specified, then @code{-W} has precedence and
-@code{-b} is ignored.
-
-When GNU extensions are enabled, the only way to avoid newline as a
-break character is to write all the break characters in the file with no
-newline at all, not even at the end of the file.  When GNU extensions
-are disabled, spaces, tabs and newlines are always considered as break
-characters even if not included in the Break file.
-
-@item -i @var{file}
-@itemx --ignore-file=@var{file}
-
-The file associated with this option contains a list of words which will
-never be taken as keywords in concordance output.  It is called the
-@dfn{Ignore file}.  The file contains exactly one word in each line; the
-end of line separation of words is not subject to the value of the
-@code{-S} option.
-
-There is a default Ignore file used by @code{ptx} when this option is
-not specified, usually found in @file{/usr/local/lib/eign} if this has
-not been changed at installation time.  If you want to deactivate the
-default Ignore file, specify @code{/dev/null} instead.
-
-@item -o @var{file}
-@itemx --only-file=@var{file}
-
-The file associated with this option contains a list of words which will
-be retained in concordance output, any word not mentioned in this file
-is ignored.  The file is called the @dfn{Only file}.  The file contains
-exactly one word in each line; the end of line separation of words is
-not subject to the value of the @code{-S} option.
-
-There is no default for the Only file.  In the case there are both an
-Only file and an Ignore file, a word will be subject to be a keyword
-only if it is given in the Only file and not given in the Ignore file.
-
-@item -r
-@itemx --references
-
-On each input line, the leading sequence of non white characters will be
-taken to be a reference that has the purpose of identifying this input
-line on the produced permuted index.  See @xref{Output formatting} for
-more information about reference production.  Using this option change
-the default value for option @code{-S}.
-
-Using this option, the program does not try very hard to remove
-references from contexts in output, but it succeeds in doing so
-@emph{when} the context ends exactly at the newline.  If option
-@code{-r} is used with @code{-S} default value, or when GNU extensions
-are disabled, this condition is always met and references are completely
-excluded from the output contexts.
-
-@item -S @var{regexp}
-@itemx --sentence-regexp=@var{regexp}
-
-This option selects which regular expression will describe the end of a
-line or the end of a sentence.  In fact, there is other distinction
-between end of lines or end of sentences than the effect of this regular
-expression, and input line boundaries have no special significance
-outside this option.  By default, when GNU extensions are enabled and if
-@code{-r} option is not used, end of sentences are used.  In this
-case, the precise @var{regex} is imported from GNU emacs:
-
-@example
-[.?!][]\"')@}]*\\($\\|\t\\|  \\)[ \t\n]*
-@end example
-
-Whenever GNU extensions are disabled or if @code{-r} option is used, end
-of lines are used; in this case, the default @var{regexp} is just:
-
-@example
-\n
-@end example
-
-Using an empty REGEXP is equivalent to completely disabling end of line or end
-of sentence recognition.  In this case, the whole file is considered to
-be a single big line or sentence.  The user might want to disallow all
-truncation flag generation as well, through option @code{-F ""}.
-@xref{Regexps, , Syntax of Regular Expressions, emacs, The GNU Emacs
-Manual}.
-
-When the keywords happen to be near the beginning of the input line or
-sentence, this often creates an unused area at the beginning of the
-output context line; when the keywords happen to be near the end of the
-input line or sentence, this often creates an unused area at the end of
-the output context line.  The program tries to fill those unused areas
-by wrapping around context in them; the tail of the input line or
-sentence is used to fill the unused area on the left of the output line;
-the head of the input line or sentence is used to fill the unused area
-on the right of the output line.
-
-As a matter of convenience to the user, many usual backslashed escape
-sequences, as found in the C language, are recognized and converted to
-the corresponding characters by @code{ptx} itself.
-
-@item -W @var{regexp}
-@itemx --word-regexp=@var{regexp}
-
-This option selects which regular expression will describe each keyword.
-By default, if GNU extensions are enabled, a word is a sequence of
-letters; the @var{regexp} used is @code{\w+}.  When GNU extensions are
-disabled, a word is by default anything which ends with a space, a tab
-or a newline; the @var{regexp} used is @code{[^ \t\n]+}.
-
-An empty REGEXP is equivalent to not using this option, letting the
-default dive in.  @xref{Regexps, , Syntax of Regular Expressions, emacs,
-The GNU Emacs Manual}.
-
-As a matter of convenience to the user, many usual backslashed escape
-sequences, as found in the C language, are recognized and converted to
-the corresponding characters by @code{ptx} itself.
-
-@end table
-
-@node Output formatting,  , Input processing, Invoking ptx
-@section Output formatting
-
-Output format is mainly controlled by @code{-O} and @code{-T} options,
-described in the table below.  When neither @code{-O} nor @code{-T} is
-selected, and if GNU extensions are enabled, the program choose an
-output format suited for a dumb terminal.  Each keyword occurrence is
-output to the center of one line, surrounded by its left and right
-contexts.  Each field is properly justified, so the concordance output
-could readily be observed.  As a special feature, if automatic
-references are selected by option @code{-A} and are output before the
-left context, that is, if option @code{-R} is @emph{not} selected, then
-a colon is added after the reference; this nicely interfaces with GNU
-Emacs @code{next-error} processing.  In this default output format, each
-white space character, like newline and tab, is merely changed to
-exactly one space, with no special attempt to compress consecutive
-spaces.  This might change in the future.  Except for those white space
-characters, every other character of the underlying set of 256
-characters is transmitted verbatim.
-
-Output format is further controlled by the following options.
-
-@table @code
-
-@item -g @var{number}
-@itemx --gap-size=@var{number}
-
-Select the size of the minimum white gap between the fields on the output
-line.
-
-@item -w @var{number}
-@itemx --width=@var{number}
-
-Select the output maximum width of each final line.  If references are
-used, they are included or excluded from the output maximum width
-depending on the value of option @code{-R}.  If this option is not
-selected, that is, when references are output before the left context,
-the output maximum width takes into account the maximum length of all
-references.  If this options is selected, that is, when references are
-output after the right context, the output maximum width does not take
-into account the space taken by references, nor the gap that precedes
-them.
-
-@item -A
-@itemx --auto-reference
-
-Select automatic references.  Each input line will have an automatic
-reference made up of the file name and the line ordinal, with a single
-colon between them.  However, the file name will be empty when standard
-input is being read.  If both @code{-A} and @code{-r} are selected, then
-the input reference is still read and skipped, but the automatic
-reference is used at output time, overriding the input reference.
-
-@item -R
-@itemx --right-side-refs
-
-In default output format, when option @code{-R} is not used, any
-reference produced by the effect of options @code{-r} or @code{-A} are
-given to the far right of output lines, after the right context.  In
-default output format, when option @code{-R} is specified, references
-are rather given to the beginning of each output line, before the left
-context.  For any other output format, option @code{-R} is almost
-ignored, except for the fact that the width of references is @emph{not}
-taken into account in total output width given by @code{-w} whenever
-@code{-R} is selected.
-
-This option is automatically selected whenever GNU extensions are
-disabled.
-
-@item -F @var{string}
-@itemx --flac-truncation=@var{string}
-
-This option will request that any truncation in the output be reported
-using the string @var{string}.  Most output fields theoretically extend
-towards the beginning or the end of the current line, or current
-sentence, as selected with option @code{-S}.  But there is a maximum
-allowed output line width, changeable through option @code{-w}, which is
-further divided into space for various output fields.  When a field has
-to be truncated because cannot extend until the beginning or the end of
-the current line to fit in the, then a truncation occurs.  By default,
-the string used is a single slash, as in @code{-F /}.
-
-@var{string} may have more than one character, as in @code{-F ...}.
-Also, in the particular case @var{string} is empty (@code{-F ""}),
-truncation flagging is disabled, and no truncation marks are appended in
-this case.
-
-As a matter of convenience to the user, many usual backslashed escape
-sequences, as found in the C language, are recognized and converted to
-the corresponding characters by @code{ptx} itself.
-
-@item -M @var{string}
-@itemx --macro-name=@var{string}
-
-Select another @var{string} to be used instead of @samp{xx}, while
-generating output suitable for @code{nroff}, @code{troff} or @TeX{}.
-
-@item -O
-@itemx --format=roff
-
-Choose an output format suitable for @code{nroff} or @code{troff}
-processing.  Each output line will look like:
-
-@example
-.xx "@var{tail}" "@var{before}" "@var{keyword_and_after}" "@var{head}" "@var{ref}"
-@end example
-
-so it will be possible to write an @samp{.xx} roff macro to take care of
-the output typesetting.  This is the default output format when GNU
-extensions are disabled.  Option @samp{-M} might be used to change
-@samp{xx} to another macro name.
-
-In this output format, each non-graphical character, like newline and
-tab, is merely changed to exactly one space, with no special attempt to
-compress consecutive spaces.  Each quote character: @kbd{"} is doubled
-so it will be correctly processed by @code{nroff} or @code{troff}.
-
-@item -T
-@itemx --format=tex
-
-Choose an output format suitable for @TeX{} processing.  Each output
-line will look like:
-
-@example
-\xx @{@var{tail}@}@{@var{before}@}@{@var{keyword}@}@{@var{after}@}@{@var{head}@}@{@var{ref}@}
-@end example
-
-@noindent
-so it will be possible to write write a @code{\xx} definition to take
-care of the output typesetting.  Note that when references are not being
-produced, that is, neither option @code{-A} nor option @code{-r} is
-selected, the last parameter of each @code{\xx} call is inhibited.
-Option @samp{-M} might be used to change @samp{xx} to another macro
-name.
-
-In this output format, some special characters, like @kbd{$}, @kbd{%},
-@kbd{&}, @kbd{#} and @kbd{_} are automatically protected with a
-backslash.  Curly brackets @kbd{@{}, @kbd{@}} are also protected with a
-backslash, but also enclosed in a pair of dollar signs to force
-mathematical mode.  The backslash itself produces the sequence
-@code{\backslash@{@}}.  Circumflex and tilde diacritics produce the
-sequence @code{^\@{ @}} and @code{~\@{ @}} respectively.  Other
-diacriticized characters of the underlying character set produce an
-appropriate @TeX{} sequence as far as possible.  The other non-graphical
-characters, like newline and tab, and all others characters which are
-not part of ASCII, are merely changed to exactly one space, with no
-special attempt to compress consecutive spaces.  Let me know how to
-improve this special character processing for @TeX{}.
-
-@end table
-
-@node Compatibility,  , Invoking ptx, Top
-@chapter The GNU extensions to @code{ptx}
-
-This version of @code{ptx} contains a few features which do not exist in
-System V @code{ptx}.  These extra features are suppressed by using the
-@samp{-G} command line option, unless overridden by other command line
-options.  Some GNU extensions cannot be recovered by overriding, so the
-simple rule is to avoid @samp{-G} if you care about GNU extensions.
-Here are the differences between this program and System V @code{ptx}.
-
-@itemize @bullet
-
-@item
-This program can read many input files at once, it always writes the
-resulting concordance on standard output.  On the other end, System V
-@code{ptx} reads only one file and produce the result on standard output
-or, if a second @var{file} parameter is given on the command, to that
-@var{file}.
-
-Having output parameters not introduced by options is a quite dangerous
-practice which GNU avoids as far as possible.  So, for using @code{ptx}
-portably between GNU and System V, you should pay attention to always
-use it with a single input file, and always expect the result on
-standard output.  You might also want to automatically configure in a
-@samp{-G} option to @code{ptx} calls in products using @code{ptx}, if
-the configurator finds that the installed @code{ptx} accepts @samp{-G}.
-
-@item
-The only options available in System V @code{ptx} are options @samp{-b},
-@samp{-f}, @samp{-g}, @samp{-i}, @samp{-o}, @samp{-r}, @samp{-t} and
-@samp{-w}.  All other options are GNU extensions and are not repeated in
-this enumeration.  Moreover, some options have a slightly different
-meaning when GNU extensions are enabled, as explained below.
-
-@item
-By default, concordance output is not formatted for @code{troff} or
-@code{nroff}.  It is rather formatted for a dumb terminal.  @code{troff}
-or @code{nroff} output may still be selected through option @code{-O}.
-
-@item
-Unless @code{-R} option is used, the maximum reference width is
-subtracted from the total output line width.  With GNU extensions
-disabled, width of references is not taken into account in the output
-line width computations.
-
-@item
-All 256 characters, even @kbd{NUL}s, are always read and processed from
-input file with no adverse effect, even if GNU extensions are disabled.
-However, System V @code{ptx} does not accept 8-bit characters, a few
-control characters are rejected, and the tilda @kbd{~} is condemned.
-
-@item
-Input line length is only limited by available memory, even if GNU
-extensions are disabled.  However, System V @code{ptx} processes only
-the first 200 characters in each line.
-
-@item
-The break (non-word) characters default to be every character except all
-letters of the underlying character set, diacriticized or not.  When GNU
-extensions are disabled, the break characters default to space, tab and
-newline only.
-
-@item
-The program makes better use of output line width.  If GNU extensions
-are disabled, the program rather tries to imitate System V @code{ptx},
-but still, there are some slight disposition glitches this program does
-not completely reproduce.
-
-@item
-The user can specify both an Ignore file and an Only file.  This is not
-allowed with System V @code{ptx}.
-
-@end itemize
-
-@bye
diff --git a/gnu/usr.bin/tar/regex.h b/gnu/usr.bin/tar/regex.h
deleted file mode 100644
index 0840861..0000000
--- a/gnu/usr.bin/tar/regex.h
+++ /dev/null
@@ -1,490 +0,0 @@
-/* Definitions for data structures and routines for the regular
-   expression library, version 0.11.
-
-   Copyright (C) 1985, 89, 90, 91, 92 Free Software Foundation, Inc.
-
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
-
-#ifndef __REGEXP_LIBRARY_H__
-#define __REGEXP_LIBRARY_H__
-
-/* POSIX says that <sys/types.h> must be included (by the caller) before
-   <regex.h>.  */
-
-#ifdef VMS
-/* VMS doesn't have `size_t' in <sys/types.h>, even though POSIX says it
-   should be there.  */
-#include <stddef.h>
-#endif
-
-
-/* The following bits are used to determine the regexp syntax we
-   recognize.  The set/not-set meanings are chosen so that Emacs syntax
-   remains the value 0.  The bits are given in alphabetical order, and
-   the definitions shifted by one from the previous bit; thus, when we
-   add or remove a bit, only one other definition need change.  */
-typedef unsigned reg_syntax_t;
-
-/* If this bit is not set, then \ inside a bracket expression is literal.
-   If set, then such a \ quotes the following character.  */
-#define RE_BACKSLASH_ESCAPE_IN_LISTS (1)
-
-/* If this bit is not set, then + and ? are operators, and \+ and \? are
-     literals. 
-   If set, then \+ and \? are operators and + and ? are literals.  */
-#define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
-
-/* If this bit is set, then character classes are supported.  They are:
-     [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
-     [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
-   If not set, then character classes are not supported.  */
-#define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
-
-/* If this bit is set, then ^ and $ are always anchors (outside bracket
-     expressions, of course).
-   If this bit is not set, then it depends:
-        ^  is an anchor if it is at the beginning of a regular
-           expression or after an open-group or an alternation operator;
-        $  is an anchor if it is at the end of a regular expression, or
-           before a close-group or an alternation operator.  
-
-   This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
-   POSIX draft 11.2 says that * etc. in leading positions is undefined.
-   We already implemented a previous draft which made those constructs
-   invalid, though, so we haven't changed the code back.  */
-#define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
-
-/* If this bit is set, then special characters are always special
-     regardless of where they are in the pattern.
-   If this bit is not set, then special characters are special only in
-     some contexts; otherwise they are ordinary.  Specifically, 
-     * + ? and intervals are only special when not after the beginning,
-     open-group, or alternation operator.  */
-#define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
-
-/* If this bit is set, then *, +, ?, and { cannot be first in an re or
-     immediately after an alternation or begin-group operator.  */
-#define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
-
-/* If this bit is set, then . matches newline.
-   If not set, then it doesn't.  */
-#define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
-
-/* If this bit is set, then . doesn't match NUL.
-   If not set, then it does.  */
-#define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
-
-/* If this bit is set, nonmatching lists [^...] do not match newline.
-   If not set, they do.  */
-#define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
-
-/* If this bit is set, either \{...\} or {...} defines an
-     interval, depending on RE_NO_BK_BRACES. 
-   If not set, \{, \}, {, and } are literals.  */
-#define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
-
-/* If this bit is set, +, ? and | aren't recognized as operators.
-   If not set, they are.  */
-#define RE_LIMITED_OPS (RE_INTERVALS << 1)
-
-/* If this bit is set, newline is an alternation operator.
-   If not set, newline is literal.  */
-#define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
-
-/* If this bit is set, then `{...}' defines an interval, and \{ and \}
-     are literals.
-  If not set, then `\{...\}' defines an interval.  */
-#define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
-
-/* If this bit is set, (...) defines a group, and \( and \) are literals.
-   If not set, \(...\) defines a group, and ( and ) are literals.  */
-#define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
-
-/* If this bit is set, then \<digit> matches <digit>.
-   If not set, then \<digit> is a back-reference.  */
-#define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
-
-/* If this bit is set, then | is an alternation operator, and \| is literal. 
-   If not set, then \| is an alternation operator, and | is literal.  */
-#define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
-
-/* If this bit is set, then an ending range point collating higher
-     than the starting range point, as in [z-a], is invalid.
-   If not set, then when ending range point collates higher than the
-     starting range point, the range is ignored.  */
-#define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
-
-/* If this bit is set, then an unmatched ) is ordinary.
-   If not set, then an unmatched ) is invalid.  */
-#define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
-
-/* This global variable defines the particular regexp syntax to use (for
-   some interfaces).  When a regexp is compiled, the syntax used is
-   stored in the pattern buffer, so changing this does not affect
-   already-compiled regexps.  */
-extern reg_syntax_t re_syntax_options;
-
-/* Define combinations of the above bits for the standard possibilities.
-   (The [[[ comments delimit what gets put into the Texinfo file, so
-   don't delete them!)  */ 
-/* [[[begin syntaxes]]] */
-#define RE_SYNTAX_EMACS 0
-
-#define RE_SYNTAX_AWK							\
-  (RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DOT_NOT_NULL			\
-   | RE_NO_BK_PARENS            | RE_NO_BK_REFS				\
-   | RE_NO_BK_VBAR               | RE_NO_EMPTY_RANGES			\
-   | RE_UNMATCHED_RIGHT_PAREN_ORD)
-
-#define RE_SYNTAX_POSIX_AWK 						\
-  (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS)
-
-#define RE_SYNTAX_GREP							\
-  (RE_BK_PLUS_QM              | RE_CHAR_CLASSES				\
-   | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS				\
-   | RE_NEWLINE_ALT)
-
-#define RE_SYNTAX_EGREP							\
-  (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS			\
-   | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE			\
-   | RE_NEWLINE_ALT       | RE_NO_BK_PARENS				\
-   | RE_NO_BK_VBAR)
-
-#define RE_SYNTAX_POSIX_EGREP						\
-  (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES)
-
-/* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
-#define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
-
-#define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
-
-/* Syntax bits common to both basic and extended POSIX regex syntax.  */
-#define _RE_SYNTAX_POSIX_COMMON						\
-  (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL		\
-   | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
-
-#define RE_SYNTAX_POSIX_BASIC						\
-  (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM)
-
-/* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
-   RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
-   isn't minimal, since other operators, such as \`, aren't disabled.  */
-#define RE_SYNTAX_POSIX_MINIMAL_BASIC					\
-  (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
-
-#define RE_SYNTAX_POSIX_EXTENDED					\
-  (_RE_SYNTAX_POSIX_COMMON | RE_CONTEXT_INDEP_ANCHORS			\
-   | RE_CONTEXT_INDEP_OPS  | RE_NO_BK_BRACES				\
-   | RE_NO_BK_PARENS       | RE_NO_BK_VBAR				\
-   | RE_UNMATCHED_RIGHT_PAREN_ORD)
-
-/* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INVALID_OPS
-   replaces RE_CONTEXT_INDEP_OPS and RE_NO_BK_REFS is added.  */
-#define RE_SYNTAX_POSIX_MINIMAL_EXTENDED				\
-  (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS			\
-   | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES				\
-   | RE_NO_BK_PARENS        | RE_NO_BK_REFS				\
-   | RE_NO_BK_VBAR	    | RE_UNMATCHED_RIGHT_PAREN_ORD)
-/* [[[end syntaxes]]] */
-
-/* Maximum number of duplicates an interval can allow.  Some systems
-   (erroneously) define this in other header files, but we want our
-   value, so remove any previous define.  */
-#ifdef RE_DUP_MAX
-#undef RE_DUP_MAX
-#endif
-#define RE_DUP_MAX ((1 << 15) - 1) 
-
-
-/* POSIX `cflags' bits (i.e., information for `regcomp').  */
-
-/* If this bit is set, then use extended regular expression syntax.
-   If not set, then use basic regular expression syntax.  */
-#define REG_EXTENDED 1
-
-/* If this bit is set, then ignore case when matching.
-   If not set, then case is significant.  */
-#define REG_ICASE (REG_EXTENDED << 1)
- 
-/* If this bit is set, then anchors do not match at newline
-     characters in the string.
-   If not set, then anchors do match at newlines.  */
-#define REG_NEWLINE (REG_ICASE << 1)
-
-/* If this bit is set, then report only success or fail in regexec.
-   If not set, then returns differ between not matching and errors.  */
-#define REG_NOSUB (REG_NEWLINE << 1)
-
-
-/* POSIX `eflags' bits (i.e., information for regexec).  */
-
-/* If this bit is set, then the beginning-of-line operator doesn't match
-     the beginning of the string (presumably because it's not the
-     beginning of a line).
-   If not set, then the beginning-of-line operator does match the
-     beginning of the string.  */
-#define REG_NOTBOL 1
-
-/* Like REG_NOTBOL, except for the end-of-line.  */
-#define REG_NOTEOL (1 << 1)
-
-
-/* If any error codes are removed, changed, or added, update the
-   `re_error_msg' table in regex.c.  */
-typedef enum
-{
-  REG_NOERROR = 0,	/* Success.  */
-  REG_NOMATCH,		/* Didn't find a match (for regexec).  */
-
-  /* POSIX regcomp return error codes.  (In the order listed in the
-     standard.)  */
-  REG_BADPAT,		/* Invalid pattern.  */
-  REG_ECOLLATE,		/* Not implemented.  */
-  REG_ECTYPE,		/* Invalid character class name.  */
-  REG_EESCAPE,		/* Trailing backslash.  */
-  REG_ESUBREG,		/* Invalid back reference.  */
-  REG_EBRACK,		/* Unmatched left bracket.  */
-  REG_EPAREN,		/* Parenthesis imbalance.  */ 
-  REG_EBRACE,		/* Unmatched \{.  */
-  REG_BADBR,		/* Invalid contents of \{\}.  */
-  REG_ERANGE,		/* Invalid range end.  */
-  REG_ESPACE,		/* Ran out of memory.  */
-  REG_BADRPT,		/* No preceding re for repetition op.  */
-
-  /* Error codes we've added.  */
-  REG_EEND,		/* Premature end.  */
-  REG_ESIZE,		/* Compiled pattern bigger than 2^16 bytes.  */
-  REG_ERPAREN		/* Unmatched ) or \); not returned from regcomp.  */
-} reg_errcode_t;
-
-/* This data structure represents a compiled pattern.  Before calling
-   the pattern compiler, the fields `buffer', `allocated', `fastmap',
-   `translate', and `no_sub' can be set.  After the pattern has been
-   compiled, the `re_nsub' field is available.  All other fields are
-   private to the regex routines.  */
-
-struct re_pattern_buffer
-{
-/* [[[begin pattern_buffer]]] */
-	/* Space that holds the compiled pattern.  It is declared as
-          `unsigned char *' because its elements are
-           sometimes used as array indexes.  */
-  unsigned char *buffer;
-
-	/* Number of bytes to which `buffer' points.  */
-  unsigned long allocated;
-
-	/* Number of bytes actually used in `buffer'.  */
-  unsigned long used;	
-
-        /* Syntax setting with which the pattern was compiled.  */
-  reg_syntax_t syntax;
-
-        /* Pointer to a fastmap, if any, otherwise zero.  re_search uses
-           the fastmap, if there is one, to skip over impossible
-           starting points for matches.  */
-  char *fastmap;
-
-        /* Either a translate table to apply to all characters before
-           comparing them, or zero for no translation.  The translation
-           is applied to a pattern when it is compiled and to a string
-           when it is matched.  */
-  char *translate;
-
-	/* Number of subexpressions found by the compiler.  */
-  size_t re_nsub;
-
-        /* Zero if this pattern cannot match the empty string, one else.
-           Well, in truth it's used only in `re_search_2', to see
-           whether or not we should use the fastmap, so we don't set
-           this absolutely perfectly; see `re_compile_fastmap' (the
-           `duplicate' case).  */
-  unsigned can_be_null : 1;
-
-        /* If REGS_UNALLOCATED, allocate space in the `regs' structure
-             for `max (RE_NREGS, re_nsub + 1)' groups.
-           If REGS_REALLOCATE, reallocate space if necessary.
-           If REGS_FIXED, use what's there.  */
-#define REGS_UNALLOCATED 0
-#define REGS_REALLOCATE 1
-#define REGS_FIXED 2
-  unsigned regs_allocated : 2;
-
-        /* Set to zero when `regex_compile' compiles a pattern; set to one
-           by `re_compile_fastmap' if it updates the fastmap.  */
-  unsigned fastmap_accurate : 1;
-
-        /* If set, `re_match_2' does not return information about
-           subexpressions.  */
-  unsigned no_sub : 1;
-
-        /* If set, a beginning-of-line anchor doesn't match at the
-           beginning of the string.  */ 
-  unsigned not_bol : 1;
-
-        /* Similarly for an end-of-line anchor.  */
-  unsigned not_eol : 1;
-
-        /* If true, an anchor at a newline matches.  */
-  unsigned newline_anchor : 1;
-
-/* [[[end pattern_buffer]]] */
-};
-
-typedef struct re_pattern_buffer regex_t;
-
-
-/* search.c (search_buffer) in Emacs needs this one opcode value.  It is
-   defined both in `regex.c' and here.  */
-#define RE_EXACTN_VALUE 1
-
-/* Type for byte offsets within the string.  POSIX mandates this.  */
-typedef int regoff_t;
-
-
-/* This is the structure we store register match data in.  See
-   regex.texinfo for a full description of what registers match.  */
-struct re_registers
-{
-  unsigned num_regs;
-  regoff_t *start;
-  regoff_t *end;
-};
-
-
-/* If `regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
-   `re_match_2' returns information about at least this many registers
-   the first time a `regs' structure is passed.  */
-#ifndef RE_NREGS
-#define RE_NREGS 30
-#endif
-
-
-/* POSIX specification for registers.  Aside from the different names than
-   `re_registers', POSIX uses an array of structures, instead of a
-   structure of arrays.  */
-typedef struct
-{
-  regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
-  regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
-} regmatch_t;
-
-/* Declarations for routines.  */
-
-/* To avoid duplicating every routine declaration -- once with a
-   prototype (if we are ANSI), and once without (if we aren't) -- we
-   use the following macro to declare argument types.  This
-   unfortunately clutters up the declarations a bit, but I think it's
-   worth it.  */
-
-#if __STDC__
-
-#define _RE_ARGS(args) args
-
-#else /* not __STDC__ */
-
-#define _RE_ARGS(args) ()
-
-#endif /* not __STDC__ */
-
-/* Sets the current default syntax to SYNTAX, and return the old syntax.
-   You can also simply assign to the `re_syntax_options' variable.  */
-extern reg_syntax_t re_set_syntax _RE_ARGS ((reg_syntax_t syntax));
-
-/* Compile the regular expression PATTERN, with length LENGTH
-   and syntax given by the global `re_syntax_options', into the buffer
-   BUFFER.  Return NULL if successful, and an error string if not.  */
-extern const char *re_compile_pattern
-  _RE_ARGS ((const char *pattern, int length,
-             struct re_pattern_buffer *buffer));
-
-
-/* Compile a fastmap for the compiled pattern in BUFFER; used to
-   accelerate searches.  Return 0 if successful and -2 if was an
-   internal error.  */
-extern int re_compile_fastmap _RE_ARGS ((struct re_pattern_buffer *buffer));
-
-
-/* Search in the string STRING (with length LENGTH) for the pattern
-   compiled into BUFFER.  Start searching at position START, for RANGE
-   characters.  Return the starting position of the match, -1 for no
-   match, or -2 for an internal error.  Also return register
-   information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
-extern int re_search
-  _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
-            int length, int start, int range, struct re_registers *regs));
-
-
-/* Like `re_search', but search in the concatenation of STRING1 and
-   STRING2.  Also, stop searching at index START + STOP.  */
-extern int re_search_2
-  _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
-             int length1, const char *string2, int length2,
-             int start, int range, struct re_registers *regs, int stop));
-
-
-/* Like `re_search', but return how many characters in STRING the regexp
-   in BUFFER matched, starting at position START.  */
-extern int re_match
-  _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string,
-             int length, int start, struct re_registers *regs));
-
-
-/* Relates to `re_match' as `re_search_2' relates to `re_search'.  */
-extern int re_match_2 
-  _RE_ARGS ((struct re_pattern_buffer *buffer, const char *string1,
-             int length1, const char *string2, int length2,
-             int start, struct re_registers *regs, int stop));
-
-
-/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
-   ENDS.  Subsequent matches using BUFFER and REGS will use this memory
-   for recording register information.  STARTS and ENDS must be
-   allocated with malloc, and must each be at least `NUM_REGS * sizeof
-   (regoff_t)' bytes long.
-
-   If NUM_REGS == 0, then subsequent matches should allocate their own
-   register data.
-
-   Unless this function is called, the first search or match using
-   PATTERN_BUFFER will allocate its own register data, without
-   freeing the old data.  */
-extern void re_set_registers
-  _RE_ARGS ((struct re_pattern_buffer *buffer, struct re_registers *regs,
-             unsigned num_regs, regoff_t *starts, regoff_t *ends));
-
-/* 4.2 bsd compatibility.  */
-extern char *re_comp _RE_ARGS ((const char *));
-extern int re_exec _RE_ARGS ((const char *));
-
-/* POSIX compatibility.  */
-extern int regcomp _RE_ARGS ((regex_t *preg, const char *pattern, int cflags));
-extern int regexec
-  _RE_ARGS ((const regex_t *preg, const char *string, size_t nmatch,
-             regmatch_t pmatch[], int eflags));
-extern size_t regerror
-  _RE_ARGS ((int errcode, const regex_t *preg, char *errbuf,
-             size_t errbuf_size));
-extern void regfree _RE_ARGS ((regex_t *preg));
-
-#endif /* not __REGEXP_LIBRARY_H__ */
-
-/*
-Local variables:
-make-backup-files: t
-version-control: t
-trim-versions-without-asking: nil
-End:
-*/
diff --git a/gnu/usr.bin/tar/y.tab.h b/gnu/usr.bin/tar/y.tab.h
deleted file mode 100644
index 4a541d2..0000000
--- a/gnu/usr.bin/tar/y.tab.h
+++ /dev/null
@@ -1,18 +0,0 @@
-#define tAGO 257
-#define tDAY 258
-#define tDAYZONE 259
-#define tID 260
-#define tMERIDIAN 261
-#define tMINUTE_UNIT 262
-#define tMONTH 263
-#define tMONTH_UNIT 264
-#define tSEC_UNIT 265
-#define tSNUMBER 266
-#define tUNUMBER 267
-#define tZONE 268
-#define tDST 269
-typedef union {
-    time_t		Number;
-    enum _MERIDIAN	Meridian;
-} YYSTYPE;
-extern YYSTYPE yylval;