Move most of the remaining USD/PSD/SMM papers into share/doc

35 files changed, 14826 insertions, 8 deletions

diff --git a/share/doc/psd/12.make/Makefile b/share/doc/psd/12.make/Makefile
index fdc38a7..b365683 100644
--- a/share/doc/psd/12.make/Makefile
+++ b/share/doc/psd/12.make/Makefile
@@ -4,6 +4,5 @@
 VOLUME=	psd/12.make
 SRCS=	stubs tutorial.ms
 MACROS=	-ms
-SRCDIR=	${.CURDIR}/../../../../usr.bin/make/PSD.doc
 
 .include <bsd.doc.mk>
diff --git a/share/doc/psd/12.make/stubs b/share/doc/psd/12.make/stubs
new file mode 100644
index 0000000..39d8def
--- /dev/null
+++ b/share/doc/psd/12.make/stubs
@@ -0,0 +1,9 @@
+.\" $FreeBSD$
+.\"
+.de Ix
+..
+.de Rd
+..
+.de Rm
+..
+.if n .ftr CR R
diff --git a/share/doc/psd/12.make/tutorial.ms b/share/doc/psd/12.make/tutorial.ms
new file mode 100644
index 0000000..320d5df
--- /dev/null
+++ b/share/doc/psd/12.make/tutorial.ms
@@ -0,0 +1,3747 @@
+.\" Copyright (c) 1988, 1989 by Adam de Boor
+.\" Copyright (c) 1989 by Berkeley Softworks
+.\" Copyright (c) 1988, 1989, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" Adam de Boor.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)tutorial.ms	8.1 (Berkeley) 8/18/93
+.\" $FreeBSD$
+.\"
+.EH 'PSD:12-%''PMake \*- A Tutorial'
+.OH 'PMake \*- A Tutorial''PSD:12-%'
+.\" xH is a macro to provide numbered headers that are automatically stuffed
+.\" into a table-of-contents, properly indented, etc. If the first argument
+.\" is numeric, it is taken as the depth for numbering (as for .NH), else
+.\" the default (1) is assumed.
+.\"
+.\" @P The initial paragraph distance.
+.\" @Q The piece of section number to increment (or 0 if none given)
+.\" @R Section header.
+.\" @S Indent for toc entry
+.\" @T Argument to NH (can't use @Q b/c giving 0 to NH resets the counter)
+.de xH
+.NH \\$1
+\\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8 \\$9
+.nr PD .1v
+.XS \\n%
+.ta 0.6i
+\\*(SN	\\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8 \\$9
+.XE
+.nr PD .3v
+..
+.ig
+.\" CW is used to place a string in fixed-width or switch to a
+.\" fixed-width font.
+.\" C is a typewriter font for a laserwriter. Use something else if
+.\" you don't have one...
+.de CW
+.ie !\\n(.$ .ft S
+.el \&\\$3\fS\\$1\fP\\$2
+..
+.\" Anything I put in a display I want to be in fixed-width
+.am DS
+.CW
+..
+.\" The stuff in .No produces a little stop sign in the left margin
+.\" that says NOTE in it. Unfortunately, it does cause a break, but
+.\" hey. Can't have everything. In case you're wondering how I came
+.\" up with such weird commands, they came from running grn on a
+.\" gremlin file...
+.de No
+.br
+.ne 0.5i
+.po -0.5i
+.br
+.mk 
+.nr g3 \\n(.f
+.nr g4 \\n(.s
+.ig ft
+.sp -1
+.\" .st cf
+\D's -1u'\D't 5u'
+.sp -1
+\h'50u'\D'l 71u 0u'\D'l 50u 50u'\D'l 0u 71u'\D'l -50u 50u'\D'l -71u 0u'\D'l -50u -50u'\D'l 0u -71u'\D'l 50u -50u'
+.sp -1
+\D't 3u'
+.sp -1
+.sp 7u
+\h'53u'\D'p 14 68u 0u 46u 46u 0u 68u -46u 46u -68u 0u -47u -46u 0u -68u 47u -46u'
+.sp -1
+.ft R
+.ps 6
+.nr g8 \\n(.d
+.ds g9 "NOTE
+.sp 74u
+\h'85u'\v'0.85n'\h-\w\\*(g9u/2u\&\\*(g9
+.sp |\\n(g8u
+.sp 166u
+.ig br
+\D't 3u'\D's -1u'
+.br
+.po
+.rt 
+.ft \\n(g3
+.ps \\n(g4
+..
+.de Bp
+.ie !\\n(.$ .IP \(bu 2
+.el .IP "\&" 2
+..
+.po +.3i
+.TL
+PMake \*- A Tutorial
+.AU
+Adam de Boor
+.AI
+Berkeley Softworks
+2150 Shattuck Ave, Penthouse
+Berkeley, CA 94704
+adam@bsw.uu.net
+\&...!uunet!bsw!adam
+.FS
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appears in all copies.
+The University of California, Berkeley Softworks, and Adam de Boor make no
+representations about the suitability of this software for any
+purpose.  It is provided "as is" without express or implied warranty.
+.FE
+.PP
+.xH 1 Introduction
+.LP
+PMake is a program for creating other programs, or anything else you
+can think of for it to do.  The basic idea behind PMake is that, for
+any given system, be it a program or a document or whatever, there
+will be some files that depend on the state of other files (on when
+they were last modified). PMake takes these dependencies, which you
+must specify, and uses them to build whatever it is you want it to
+build.
+.LP
+PMake is almost fully-compatible with Make, with which you may already
+be familiar. PMake's most important feature is its ability to run
+several different jobs at once, making the creation of systems
+considerably faster. It also has a great deal more functionality than
+Make. Throughout the text, whenever something is mentioned that is an
+important difference between PMake and Make (i.e.  something that will
+cause a makefile to fail if you don't do something about it), or is
+simply important, it will be flagged with a little sign in the left
+margin, like this:
+.No
+.LP
+This tutorial is divided into three main sections corresponding to basic,
+intermediate and advanced PMake usage. If you already know Make well,
+you will only need to skim chapter 2 (there are some aspects of
+PMake that I consider basic to its use that didn't exist in Make).
+Things in chapter 3 make life much easier, while those in chapter 4
+are strictly for those who know what they are doing. Chapter 5 has
+definitions for the jargon I use and chapter 6 contains possible
+solutions to the problems presented throughout the tutorial.
+.xH 1 The Basics of PMake
+.LP
+PMake takes as input a file that tells a) which files depend on which
+other files to be complete and b) what to do about files that are
+``out-of-date.'' This file is known as a ``makefile'' and is usually
+.Ix 0 def makefile
+kept in the top-most directory of the system to be built. While you
+can call the makefile anything you want, PMake will look for
+.CW Makefile
+and
+.CW makefile
+(in that order) in the current directory if you don't tell it
+otherwise.
+.Ix 0 def makefile default
+To specify a different makefile, use the
+.B \-f
+flag (e.g.
+.CW "pmake -f program.mk" ''). ``
+.Ix 0 ref flags -f
+.Ix 0 ref makefile other
+.LP
+A makefile has four different types of lines in it:
+.RS
+.IP \(bu 2
+File dependency specifications
+.IP \(bu 2
+Creation commands
+.IP \(bu 2
+Variable assignments
+.IP \(bu 2
+Comments, include statements and conditional directives
+.RE
+.LP
+Any line may be continued over multiple lines by ending it with a
+backslash.
+.Ix 0 def "continuation line"
+The backslash, following newline and any initial whitespace
+on the following line are compressed into a single space before the
+input line is examined by PMake.
+.xH 2 Dependency Lines
+.LP
+As mentioned in the introduction, in any system, there are
+dependencies between the files that make up the system.  For instance,
+in a program made up of several C source files and one header file,
+the C files will need to be re-compiled should the header file be
+changed. For a document of several chapters and one macro file, the
+chapters will need to be reprocessed if any of the macros changes.
+.Ix 0 def "dependency"
+These are dependencies and are specified by means of dependency lines in
+the makefile.
+.LP
+.Ix 0 def "dependency line"
+On a dependency line, there are targets and sources, separated by a
+one- or two-character operator.
+The targets ``depend'' on the sources and are usually created from
+them.
+.Ix 0 def target
+.Ix 0 def source
+.Ix 0 ref operator
+Any number of targets and sources may be specified on a dependency line.
+All the targets in the line are made to depend on all the sources.
+Targets and sources need not be actual files, but every source must be
+either an actual file or another target in the makefile.
+If you run out of room, use a backslash at the end of the line to continue onto
+the next one.
+.LP
+Any file may be a target and any file may be a source, but the
+relationship between the two (or however many) is determined by the
+``operator'' that separates them.
+.Ix 0 def operator
+Three types of operators exist: one specifies that the datedness of a
+target is determined by the state of its sources, while another
+specifies other files (the sources) that need to be dealt with before
+the target can be re-created. The third operator is very similar to
+the first, with the additional condition that the target is
+out-of-date if it has no sources. These operations are represented by
+the colon, the exclamation point and the double-colon, respectively, and are
+mutually exclusive. Their exact semantics are as follows:
+.IP ":"
+.Ix 0 def operator colon
+.Ix 0 def :
+If a colon is used, a target on the line is considered to be
+``out-of-date'' (and in need of creation) if 
+.RS
+.IP \(bu 2
+any of the sources has been modified more recently than the target, or
+.IP \(bu 2
+the target doesn't exist.
+.RE
+.Ix 0 def out-of-date
+.IP "\&"
+Under this operation, steps will be taken to re-create the target only
+if it is found to be out-of-date by using these two rules.
+.IP "!"
+.Ix 0 def operator force
+.Ix 0 def !
+If an exclamation point is used, the target will always be re-created,
+but this will not happen until all of its sources have been examined
+and re-created, if necessary.
+.IP "::"
+.Ix 0 def operator double-colon
+.Ix 0 def ::
+If a double-colon is used, a target is out-of-date if:
+.RS
+.IP \(bu 2
+any of the sources has been modified more recently than the target, or
+.IP \(bu 2
+the target doesn't exist, or
+.IP \(bu 2
+the target has no sources.
+.RE
+.IP "\&"
+If the target is out-of-date according to these rules, it will be re-created.
+This operator also does something else to the targets, but I'll go
+into that in the next section (``Shell Commands'').
+.LP
+Enough words, now for an example. Take that C program I mentioned
+earlier. Say there are three C files
+.CW a.c , (
+.CW b.c
+and
+.CW  c.c )
+each of which
+includes the file
+.CW defs.h .
+The dependencies between the files could then be expressed as follows:
+.DS
+program         : a.o b.o c.o
+a.o b.o c.o     : defs.h
+a.o             : a.c
+b.o             : b.c
+c.o             : c.c
+.DE
+.LP
+You may be wondering at this point, where
+.CW a.o ,
+.CW b.o
+and
+.CW c.o
+came in and why
+.I they
+depend on
+.CW defs.h
+and the C files don't. The reason is quite simple:
+.CW program
+cannot be made by linking together .c files \*- it must be
+made from .o files. Likewise, if you change
+.CW defs.h ,
+it isn't the .c files that need to be re-created, it's the .o files.
+If you think of dependencies in these terms \*- which files (targets)
+need to be created from which files (sources) \*- you should have no problems.
+.LP
+An important thing to notice about the above example, is that all the
+\&.o files appear as targets on more than one line. This is perfectly
+all right: the target is made to depend on all the sources mentioned
+on all the dependency lines. E.g.
+.CW a.o
+depends on both
+.CW defs.h
+and
+.CW a.c .
+.Ix 0 ref dependency
+.No
+.LP
+The order of the dependency lines in the makefile is
+important: the first target on the first dependency line in the
+makefile will be the one that gets made if you don't say otherwise.
+That's why
+.CW program
+comes first in the example makefile, above.
+.LP
+Both targets and sources may contain the standard C-Shell wildcard
+characters
+.CW { , (
+.CW } ,
+.CW * ,
+.CW ? ,
+.CW [ ,
+and
+.CW ] ),
+but the non-curly-brace ones may only appear in the final component
+(the file portion) of the target or source. The characters mean the
+following things:
+.IP \fB{}\fP
+These enclose a comma-separated list of options and cause the pattern
+to be expanded once for each element of the list. Each expansion
+contains a different element. For example, 
+.CW src/{whiffle,beep,fish}.c
+expands to the three words
+.CW src/whiffle.c ,
+.CW src/beep.c ,
+and 
+.CW src/fish.c .
+These braces may be nested and, unlike the other wildcard characters,
+the resulting words need not be actual files. All other wildcard
+characters are expanded using the files that exist when PMake is
+started.
+.IP \fB*\fP
+This matches zero or more characters of any sort. 
+.CW src/*.c
+will expand to the same three words as above as long as 
+.CW src
+contains those three files (and no other files that end in 
+.CW .c ).
+.IP \fB?\fP
+Matches any single character.
+.IP \fB[]\fP
+This is known as a character class and contains either a list of
+single characters, or a series of character ranges 
+.CW a-z , (
+for example means all characters between a and z), or both. It matches
+any single character contained in the list. E.g.
+.CW [A-Za-z]
+will match all letters, while
+.CW [0123456789]
+will match all numbers.
+.xH 2 Shell Commands
+.LP
+``Isn't that nice,'' you say to yourself, ``but how are files
+actually `re-created,' as he likes to spell it?''
+The re-creation is accomplished by commands you place in the makefile.
+These commands are passed to the Bourne shell (better known as
+``/bin/sh'') to be executed and are
+.Ix 0 ref shell
+.Ix 0 ref re-creation
+.Ix 0 ref update
+expected to do what's necessary to update the target file (PMake
+doesn't actually check to see if the target was created. It just
+assumes it's there).
+.Ix 0 ref target
+.LP
+Shell commands in a makefile look a lot like shell commands you would
+type at a terminal, with one important exception: each command in a
+makefile
+.I must
+be preceded by at least one tab.
+.LP
+Each target has associated with it a shell script made up of
+one or more of these shell commands. The creation script for a target
+should immediately follow the dependency line for that target. While
+any given target may appear on more than one dependency line, only one
+of these dependency lines may be followed by a creation script, unless
+the `::' operator was used on the dependency line.
+.Ix 0 ref operator double-colon
+.Ix 0 ref ::
+.No
+.LP
+If the double-colon was used, each dependency line for the target
+may be followed by a shell script. That script will only be executed
+if the target on the associated dependency line is out-of-date with
+respect to the sources on that line, according to the rules I gave
+earlier.
+I'll give you a good example of this later on.
+.LP
+To expand on the earlier makefile, you might add commands as follows:
+.DS
+program         : a.o b.o c.o
+        cc a.o b.o c.o \-o program
+a.o b.o c.o     : defs.h
+a.o             : a.c
+        cc \-c a.c
+b.o             : b.c
+        cc \-c b.c
+c.o             : c.c
+        cc \-c c.c
+.DE
+.LP
+Something you should remember when writing a makefile is, the
+commands will be executed if the
+.I target
+on the dependency line is out-of-date, not the sources.
+.Ix 0 ref target
+.Ix 0 ref source
+.Ix 0 ref out-of-date
+In this example, the command
+.CW "cc \-c a.c" '' ``
+will be executed if
+.CW a.o
+is out-of-date. Because of the `:' operator,
+.Ix 0 ref :
+.Ix 0 ref operator colon
+this means that should
+.CW a.c
+.I or
+.CW defs.h
+have been modified more recently than
+.CW a.o ,
+the command will be executed
+.CW a.o "\&" (
+will be considered out-of-date).
+.Ix 0 ref out-of-date
+.LP
+Remember how I said the only difference between a makefile shell
+command and a regular shell command was the leading tab? I lied. There
+is another way in which makefile commands differ from regular ones.
+The first two characters after the initial whitespace are treated
+specially.
+If they are any combination of `@' and `\-', they cause PMake to do
+different things.
+.LP
+In most cases, shell commands are printed before they're
+actually executed. This is to keep you informed of what's going on. If
+an `@' appears, however, this echoing is suppressed. In the case of an
+.CW echo
+command, say
+.CW "echo Linking index" ,'' ``
+it would be
+rather silly to see
+.DS
+echo Linking index
+Linking index
+.DE
+.LP
+so PMake allows you to place an `@' before the command
+.CW "@echo Linking index" '') (``
+to prevent the command from being printed.
+.LP
+The other special character is the `\-'. In case you didn't know,
+shell commands finish with a certain ``exit status.'' This status is
+made available by the operating system to whatever program invoked the
+command. Normally this status will be 0 if everything went ok and
+non-zero if something went wrong. For this reason, PMake will consider
+an error to have occurred if one of the shells it invokes returns a non-zero
+status. When it detects an error, PMake's usual action is to abort
+whatever it's doing and exit with a non-zero status itself (any other
+targets that were being created will continue being made, but nothing
+new will be started. PMake will exit after the last job finishes).
+This behavior can be altered, however, by placing a `\-' at the front
+of a command
+.CW "\-mv index index.old" ''), (``
+certain command-line arguments,
+or doing other things, to be detailed later. In such
+a case, the non-zero status is simply ignored and PMake keeps chugging
+along.
+.No
+.LP
+Because all the commands are given to a single shell to execute, such
+things as setting shell variables, changing directories, etc., last
+beyond the command in which they are found. This also allows shell
+compound commands (like
+.CW for
+loops) to be entered in a natural manner.
+Since this could cause problems for some makefiles that depend on
+each command being executed by a single shell, PMake has a
+.B \-B
+.Ix 0 ref compatibility
+.Ix 0 ref flags -B
+flag (it stands for backwards-compatible) that forces each command to
+be given to a separate shell. It also does several other things, all
+of which I discourage since they are now old-fashioned.\|.\|.\|.
+.No
+.LP
+A target's shell script is fed to the shell on its (the shell's) input stream.
+This means that any commands, such as
+.CW ci
+that need to get input from the terminal won't work right \*- they'll
+get the shell's input, something they probably won't find to their
+liking. A simple way around this is to give a command like this:
+.DS
+ci $(SRCS) < /dev/tty
+.DE
+This would force the program's input to come from the terminal. If you
+can't do this for some reason, your only other alternative is to use
+PMake in its fullest compatibility mode. See 
+.B Compatibility
+in chapter 4.
+.Ix 0 ref compatibility
+.LP
+.xH 2 Variables
+.LP
+PMake, like Make before it, has the ability to save text in variables
+to be recalled later at your convenience. Variables in PMake are used
+much like variables in the shell and, by tradition, consist of
+all upper-case letters (you don't
+.I have
+to use all upper-case letters.
+In fact there's nothing to stop you from calling a variable
+.CW @^&$%$ .
+Just tradition). Variables are assigned-to using lines of the form
+.Ix 0 def variable assignment
+.DS
+VARIABLE = value
+.DE
+.Ix 0 def variable assignment
+appended-to by
+.DS
+VARIABLE += value
+.DE
+.Ix 0 def variable appending
+.Ix 0 def variable assignment appended
+.Ix 0 def +=
+conditionally assigned-to (if the variable isn't already defined) by
+.DS
+VARIABLE ?= value
+.DE
+.Ix 0 def variable assignment conditional
+.Ix 0 def ?=
+and assigned-to with expansion (i.e. the value is expanded (see below)
+before being assigned to the variable\*-useful for placing a value at
+the beginning of a variable, or other things) by
+.DS
+VARIABLE := value
+.DE
+.Ix 0 def variable assignment expanded
+.Ix 0 def :=
+.LP
+Any whitespace before
+.I value
+is stripped off. When appending, a space is placed between the old
+value and the stuff being appended.
+.LP
+The final way a variable may be assigned to is using
+.DS
+VARIABLE != shell-command
+.DE
+.Ix 0 def variable assignment shell-output
+.Ix 0 def !=
+In this case, 
+.I shell-command
+has all its variables expanded (see below) and is passed off to a
+shell to execute. The output of the shell is then placed in the
+variable. Any newlines (other than the final one) are replaced by
+spaces before the assignment is made. This is typically used to find
+the current directory via a line like:
+.DS
+CWD             != pwd
+.DE
+.LP
+.B Note:
+this is intended to be used to execute commands that produce small amounts
+of output (e.g. ``pwd''). The implementation is less than intelligent and will
+likely freeze if you execute something that produces thousands of
+bytes of output (8 Kb is the limit on many UNIX systems).
+.LP
+The value of a variable may be retrieved by enclosing the variable
+name in parentheses or curly braces and preceding the whole thing
+with a dollar sign.
+.LP
+For example, to set the variable CFLAGS to the string
+.CW "\-I/sprite/src/lib/libc \-O" ,'' ``
+you would place a line
+.DS
+CFLAGS = \-I/sprite/src/lib/libc \-O
+.DE
+in the makefile and use the word
+.CW "$(CFLAGS)"
+wherever you would like the string
+.CW "\-I/sprite/src/lib/libc \-O"
+to appear. This is called variable expansion.
+.Ix 0 def variable expansion
+.No
+.LP
+Unlike Make, PMake will not expand a variable unless it knows
+the variable exists. E.g. if you have a
+.CW "${i}"
+in a shell command and you have not assigned a value to the variable
+.CW i 
+(the empty string is considered a value, by the way), where Make would have
+substituted the empty string, PMake will leave the
+.CW "${i}"
+alone.
+To keep PMake from substituting for a variable it knows, precede the
+dollar sign with another dollar sign.
+(e.g. to pass
+.CW "${HOME}"
+to the shell, use
+.CW "$${HOME}" ).
+This causes PMake, in effect, to expand the
+.CW $
+macro, which expands to a single
+.CW $ .
+For compatibility, Make's style of variable expansion will be used
+if you invoke PMake with any of the compatibility flags (\c
+.B \-V ,
+.B \-B
+or
+.B \-M .
+The
+.B \-V
+flag alters just the variable expansion).
+.Ix 0 ref flags -V
+.Ix 0 ref flags -B
+.Ix 0 ref flags -M
+.Ix 0 ref compatibility
+.LP
+.Ix 0 ref variable expansion
+There are two different times at which variable expansion occurs:
+When parsing a dependency line, the expansion occurs immediately
+upon reading the line. If any variable used on a dependency line is
+undefined, PMake will print a message and exit.
+Variables in shell commands are expanded when the command is
+executed.
+Variables used inside another variable are expanded whenever the outer
+variable is expanded (the expansion of an inner variable has no effect
+on the outer variable. I.e. if the outer variable is used on a dependency
+line and in a shell command, and the inner variable changes value
+between when the dependency line is read and the shell command is
+executed, two different values will be substituted for the outer
+variable).
+.Ix 0 def variable types
+.LP
+Variables come in four flavors, though they are all expanded the same
+and all look about the same. They are (in order of expanding scope):
+.RS
+.IP \(bu 2
+Local variables.
+.Ix 0 ref variable local
+.IP \(bu 2
+Command-line variables.
+.Ix 0 ref variable command-line
+.IP \(bu 2
+Global variables.
+.Ix 0 ref variable global
+.IP \(bu 2
+Environment variables.
+.Ix 0 ref variable environment
+.RE
+.LP
+The classification of variables doesn't matter much, except that the
+classes are searched from the top (local) to the bottom (environment)
+when looking up a variable. The first one found wins.
+.xH 3 Local Variables
+.LP
+.Ix 0 def variable local
+Each target can have as many as seven local variables. These are
+variables that are only ``visible'' within that target's shell script
+and contain such things as the target's name, all of its sources (from
+all its dependency lines), those sources that were out-of-date, etc.
+Four local variables are defined for all targets. They are:
+.RS
+.IP ".TARGET"
+.Ix 0 def variable local .TARGET
+.Ix 0 def .TARGET
+The name of the target.
+.IP ".OODATE"
+.Ix 0 def variable local .OODATE
+.Ix 0 def .OODATE
+The list of the sources for the target that were considered out-of-date.
+The order in the list is not guaranteed to be the same as the order in
+which the dependencies were given.
+.IP ".ALLSRC"
+.Ix 0 def variable local .ALLSRC
+.Ix 0 def .ALLSRC
+The list of all sources for this target in the order in which they
+were given.
+.IP ".PREFIX"
+.Ix 0 def variable local .PREFIX
+.Ix 0 def .PREFIX
+The target without its suffix and without any leading path. E.g. for
+the target
+.CW ../../lib/compat/fsRead.c ,
+this variable would contain
+.CW fsRead .
+.RE
+.LP
+Three other local variables are set only for certain targets under
+special circumstances. These are the ``.IMPSRC,''
+.Ix 0 ref variable local .IMPSRC
+.Ix 0 ref .IMPSRC
+``.ARCHIVE,''
+.Ix 0 ref variable local .ARCHIVE
+.Ix 0 ref .ARCHIVE
+and ``.MEMBER''
+.Ix 0 ref variable local .MEMBER
+.Ix 0 ref .MEMBER
+variables. When they are set and how they are used is described later.
+.LP
+Four of these variables may be used in sources as well as in shell
+scripts.
+.Ix 0 def "dynamic source"
+.Ix 0 def source dynamic
+These are ``.TARGET'', ``.PREFIX'', ``.ARCHIVE'' and ``.MEMBER''. The
+variables in the sources are expanded once for each target on the
+dependency line, providing what is known as a ``dynamic source,''
+.Rd 0
+allowing you to specify several dependency lines at once. For example,
+.DS
+$(OBJS)         : $(.PREFIX).c
+.DE
+will create a dependency between each object file and its
+corresponding C source file.
+.xH 3 Command-line Variables
+.LP
+.Ix 0 def variable command-line
+Command-line variables are set when PMake is first invoked by giving a
+variable assignment as one of the arguments. For example,
+.DS
+pmake "CFLAGS = -I/sprite/src/lib/libc -O"
+.DE
+would make 
+.CW CFLAGS
+be a command-line variable with the given value. Any assignments to
+.CW CFLAGS
+in the makefile will have no effect, because once it
+is set, there is (almost) nothing you can do to change a command-line
+variable (the search order, you see). Command-line variables may be
+set using any of the four assignment operators, though only
+.CW =
+and
+.CW ?=
+behave as you would expect them to, mostly because assignments to
+command-line variables are performed before the makefile is read, thus
+the values set in the makefile are unavailable at the time.
+.CW +=
+.Ix 0 ref +=
+.Ix 0 ref variable assignment appended
+is the same as
+.CW = ,
+because the old value of the variable is sought only in the scope in
+which the assignment is taking place (for reasons of efficiency that I
+won't get into here).
+.CW :=
+and
+.CW ?=
+.Ix 0 ref :=
+.Ix 0 ref ?=
+.Ix 0 ref variable assignment expanded
+.Ix 0 ref variable assignment conditional
+will work if the only variables used are in the environment.
+.CW !=
+is sort of pointless to use from the command line, since the same
+effect can no doubt be accomplished using the shell's own command
+substitution mechanisms (backquotes and all that).
+.xH 3 Global Variables
+.LP
+.Ix 0 def variable global
+Global variables are those set or appended-to in the makefile.
+There are two classes of global variables: those you set and those PMake sets.
+As I said before, the ones you set can have any name you want them to have,
+except they may not contain a colon or an exclamation point.
+The variables PMake sets (almost) always begin with a
+period and always contain upper-case letters, only. The variables are
+as follows:
+.RS
+.IP .PMAKE
+.Ix 0 def variable global .PMAKE
+.Ix 0 def .PMAKE
+.Ix 0 def variable global MAKE
+.Ix 0 def MAKE
+The name by which PMake was invoked is stored in this variable. For
+compatibility, the name is also stored in the MAKE variable.
+.IP .MAKEFLAGS
+.Ix 0 def variable global .MAKEFLAGS
+.Ix 0 def .MAKEFLAGS variable
+.Ix 0 def variable global MFLAGS
+.Ix 0 def MFLAGS
+All the relevant flags with which PMake was invoked. This does not
+include such things as
+.B \-f
+or variable assignments. Again for compatibility, this value is stored
+in the MFLAGS variable as well.
+.RE
+.LP
+Two other variables, ``.INCLUDES'' and ``.LIBS,'' are covered in the
+section on special targets in chapter 3.
+.Ix 0 ref variable global .INCLUDES
+.Ix 0 ref variable global .LIBS
+.LP
+Global variables may be deleted using lines of the form:
+.Ix 0 def #undef
+.Ix 0 def variable deletion
+.DS
+#undef \fIvariable\fP
+.DE
+The
+.CW # ' `
+must be the first character on the line. Note that this may only be
+done on global variables.
+.xH 3 Environment Variables
+.LP
+.Ix 0 def variable environment
+Environment variables are passed by the shell that invoked PMake and
+are given by PMake to each shell it invokes. They are expanded like
+any other variable, but they cannot be altered in any way.
+.LP
+One special environment variable,
+.CW PMAKE ,
+.Ix 0 def variable environment PMAKE
+is examined by PMake for command-line flags, variable assignments,
+etc., it should always use. This variable is examined before the
+actual arguments to PMake are. In addition, all flags given to PMake,
+either through the
+.CW PMAKE
+variable or on the command line, are placed in this environment
+variable and exported to each shell PMake executes. Thus recursive
+invocations of PMake automatically receive the same flags as the
+top-most one.
+.LP
+Using all these variables, you can compress the sample makefile even more:
+.DS
+OBJS            = a.o b.o c.o
+program         : $(OBJS)
+        cc $(.ALLSRC) \-o $(.TARGET)
+$(OBJS)         : defs.h
+a.o             : a.c
+        cc \-c a.c
+b.o             : b.c
+        cc \-c b.c
+c.o             : c.c
+        cc \-c c.c
+.DE
+.Ix 0 ref variable local .ALLSRC
+.Ix 0 ref .ALLSRC
+.Ix 0 ref variable local .TARGET
+.Ix 0 ref .TARGET
+.Rd 3
+.xH 2 Comments
+.LP
+.Ix 0 def comments
+Comments in a makefile start with a `#' character and extend to the
+end of the line. They may appear
+anywhere you want them, except in a shell command (though the shell
+will treat it as a comment, too). If, for some reason, you need to use the `#'
+in a variable or on a dependency line, put a backslash in front of it.
+PMake will compress the two into a single `#' (Note: this isn't true
+if PMake is operating in full-compatibility mode).
+.Ix 0 ref flags -M
+.Ix 0 ref compatibility
+.xH 2 Parallelism
+.No
+.LP
+PMake was specifically designed to re-create several targets at once,
+when possible. You do not have to do anything special to cause this to
+happen (unless PMake was configured to not act in parallel, in which
+case you will have to make use of the
+.B \-L
+and
+.B \-J
+flags (see below)),
+.Ix 0 ref flags -L
+.Ix 0 ref flags -J
+but you do have to be careful at times.
+.LP
+There are several problems you are likely to encounter. One is
+that some makefiles (and programs) are written in such a way that it is
+impossible for two targets to be made at once. The program
+.CW xstr ,
+for example,
+always modifies the files
+.CW strings
+and
+.CW x.c .
+There is no way to change it. Thus you cannot run two of them at once
+without something being trashed. Similarly, if you have commands
+in the makefile that always send output to the same file, you will not
+be able to make more than one target at once unless you change the
+file you use. You can, for instance, add a
+.CW $$$$
+to the end of the file name to tack on the process ID of the shell
+executing the command (each
+.CW $$
+expands to a single
+.CW $ ,
+thus giving you the shell variable
+.CW $$ ).
+Since only one shell is used for all the
+commands, you'll get the same file name for each command in the
+script.
+.LP
+The other problem comes from improperly-specified dependencies that
+worked in Make because of its sequential, depth-first way of examining
+them. While I don't want to go into depth on how PMake
+works (look in chapter 4 if you're interested), I will warn you that
+files in two different ``levels'' of the dependency tree may be
+examined in a different order in PMake than they were in Make. For
+example, given the makefile
+.DS
+a               : b c
+b               : d
+.DE
+PMake will examine the targets in the order
+.CW c ,
+.CW d ,
+.CW b ,
+.CW a .
+If the makefile's author expected PMake to abort before making
+.CW c
+if an error occurred while making
+.CW b ,
+or if
+.CW b
+needed to exist before
+.CW c
+was made,
+s/he will be sorely disappointed. The dependencies are
+incomplete, since in both these cases,
+.CW c
+would depend on
+.CW b .
+So watch out.
+.LP
+Another problem you may face is that, while PMake is set up to handle the
+output from multiple jobs in a graceful fashion, the same is not so for input.
+It has no way to regulate input to different jobs,
+so if you use the redirection from
+.CW /dev/tty
+I mentioned earlier, you must be careful not to run two of the jobs at once.
+.xH 2 Writing and Debugging a Makefile
+.LP
+Now you know most of what's in a makefile, what do you do next? There
+are two choices: (1) use one of the uncommonly-available makefile
+generators or (2) write your own makefile (I leave out the third choice of
+ignoring PMake and doing everything by hand as being beyond the bounds
+of common sense).
+.LP
+When faced with the writing of a makefile, it is usually best to start
+from first principles: just what
+.I are
+you trying to do? What do you want the makefile finally to produce?
+.LP
+To begin with a somewhat traditional example, let's say you need to
+write a makefile to create a program,
+.CW expr ,
+that takes standard infix expressions and converts them to prefix form (for
+no readily apparent reason). You've got three source files, in C, that
+make up the program:
+.CW main.c ,
+.CW parse.c ,
+and
+.CW output.c .
+Harking back to my pithy advice about dependency lines, you write the
+first line of the file:
+.DS
+expr            : main.o parse.o output.o
+.DE
+because you remember
+.CW expr
+is made from
+.CW .o
+files, not
+.CW .c
+files. Similarly for the
+.CW .o
+files you produce the lines:
+.DS
+main.o          : main.c
+parse.o         : parse.c
+output.o        : output.c
+main.o parse.o output.o : defs.h
+.DE
+.LP
+Great. You've now got the dependencies specified. What you need now is
+commands. These commands, remember, must produce the target on the
+dependency line, usually by using the sources you've listed.
+You remember about local variables? Good, so it should come
+to you as no surprise when you write
+.DS
+expr            : main.o parse.o output.o
+        cc -o $(.TARGET) $(.ALLSRC)
+.DE
+Why use the variables? If your program grows to produce postfix
+expressions too (which, of course, requires a name change or two), it
+is one fewer place you have to change the file. You cannot do this for
+the object files, however, because they depend on their corresponding
+source files
+.I and
+.CW defs.h ,
+thus if you said
+.DS
+	cc -c $(.ALLSRC)
+.DE
+you'd get (for
+.CW main.o ):
+.DS
+	cc -c main.c defs.h
+.DE
+which is wrong. So you round out the makefile with these lines:
+.DS
+main.o          : main.c
+        cc -c main.c
+parse.o         : parse.c
+        cc -c parse.c
+output.o        : output.c
+        cc -c output.c
+.DE
+.LP
+The makefile is now complete and will, in fact, create the program you
+want it to without unnecessary compilations or excessive typing on
+your part. There are two things wrong with it, however (aside from it
+being altogether too long, something I'll address in chapter 3):
+.IP 1)
+The string
+.CW "main.o parse.o output.o" '' ``
+is repeated twice, necessitating two changes when you add postfix
+(you were planning on that, weren't you?). This is in direct violation
+of de Boor's First Rule of writing makefiles:
+.QP
+.I
+Anything that needs to be written more than once
+should be placed in a variable.
+.IP "\&"
+I cannot emphasize this enough as being very important to the
+maintenance of a makefile and its program.
+.IP 2)
+There is no way to alter the way compilations are performed short of
+editing the makefile and making the change in all places. This is evil
+and violates de Boor's Second Rule, which follows directly from the
+first:
+.QP
+.I
+Any flags or programs used inside a makefile should be placed in a variable so
+they may be changed, temporarily or permanently, with the greatest ease.
+.LP
+The makefile should more properly read:
+.DS
+OBJS            = main.o parse.o output.o
+expr            : $(OBJS)
+        $(CC) $(CFLAGS) -o $(.TARGET) $(.ALLSRC)
+main.o          : main.c
+        $(CC) $(CFLAGS) -c main.c
+parse.o         : parse.c
+        $(CC) $(CFLAGS) -c parse.c
+output.o        : output.c
+        $(CC) $(CFLAGS) -c output.c
+$(OBJS)         : defs.h
+.DE
+Alternatively, if you like the idea of dynamic sources mentioned in
+section 2.3.1,
+.Rm 0 2.3.1
+.Rd 4
+.Ix 0 ref "dynamic source"
+.Ix 0 ref source dynamic
+you could write it like this:
+.DS
+OBJS            = main.o parse.o output.o
+expr            : $(OBJS)
+        $(CC) $(CFLAGS) -o $(.TARGET) $(.ALLSRC)
+$(OBJS)         : $(.PREFIX).c defs.h
+        $(CC) $(CFLAGS) -c $(.PREFIX).c
+.DE
+These two rules and examples lead to de Boor's First Corollary:
+.QP
+.I
+Variables are your friends.
+.LP
+Once you've written the makefile comes the sometimes-difficult task of
+.Ix 0 ref debugging
+making sure the darn thing works. Your most helpful tool to make sure
+the makefile is at least syntactically correct is the
+.B \-n
+.Ix 0 ref flags -n
+flag, which allows you to see if PMake will choke on the makefile. The
+second thing the
+.B \-n
+flag lets you do is see what PMake would do without it actually doing
+it, thus you can make sure the right commands would be executed were
+you to give PMake its head.
+.LP
+When you find your makefile isn't behaving as you hoped, the first
+question that comes to mind (after ``What time is it, anyway?'') is
+``Why not?'' In answering this, two flags will serve you well:
+.CW "-d m" '' ``
+.Ix 0 ref flags -d
+and
+.CW "-p 2" .'' ``
+.Ix 0 ref flags -p
+The first causes PMake to tell you as it examines each target in the
+makefile and indicate why it is deciding whatever it is deciding. You
+can then use the information printed for other targets to see where
+you went wrong. The
+.CW "-p 2" '' ``
+flag makes PMake print out its internal state when it is done,
+allowing you to see that you forgot to make that one chapter depend on
+that file of macros you just got a new version of. The output from
+.CW "-p 2" '' ``
+is intended to resemble closely a real makefile, but with additional
+information provided and with variables expanded in those commands
+PMake actually printed or executed.
+.LP
+Something to be especially careful about is circular dependencies.
+.Ix 0 def dependency circular
+E.g.
+.DS
+a		: b
+b		: c d
+d		: a
+.DE
+In this case, because of how PMake works,
+.CW c
+is the only thing PMake will examine, because
+.CW d
+and
+.CW a
+will effectively fall off the edge of the universe, making it
+impossible to examine
+.CW b
+(or them, for that matter).
+PMake will tell you (if run in its normal mode) all the targets
+involved in any cycle it looked at (i.e. if you have two cycles in the
+graph (naughty, naughty), but only try to make a target in one of
+them, PMake will only tell you about that one. You'll have to try to
+make the other to find the second cycle). When run as Make, it will
+only print the first target in the cycle.
+.xH 2 Invoking PMake
+.LP
+.Ix 0 ref flags
+.Ix 0 ref arguments
+.Ix 0 ref usage
+PMake comes with a wide variety of flags to choose from.
+They may appear in any order, interspersed with command-line variable
+assignments and targets to create.
+The flags are as follows:
+.IP "\fB\-d\fP \fIwhat\fP"
+.Ix 0 def flags -d
+.Ix 0 ref debugging
+This causes PMake to spew out debugging information that
+may prove useful to you. If you can't
+figure out why PMake is doing what it's doing, you might try using
+this flag. The
+.I what
+parameter is a string of single characters that tell PMake what
+aspects you are interested in. Most of what I describe will make
+little sense to you, unless you've dealt with Make before. Just
+remember where this table is and come back to it as you read on.
+The characters and the information they produce are as follows:
+.RS
+.IP a
+Archive searching and caching.
+.IP c
+Conditional evaluation.
+.IP d
+The searching and caching of directories.
+.IP j
+Various snippets of information related to the running of the multiple
+shells. Not particularly interesting.
+.IP m
+The making of each target: what target is being examined; when it was
+last modified; whether it is out-of-date; etc.
+.IP p
+Makefile parsing.
+.IP r
+Remote execution.
+.IP s
+The application of suffix-transformation rules. (See chapter 3)
+.IP t
+The maintenance of the list of targets.
+.IP v
+Variable assignment.
+.RE
+.IP "\&"
+Of these all, the
+.CW m
+and
+.CW s
+letters will be most useful to you.
+If the
+.B \-d
+is the final argument or the argument from which it would get these
+key letters (see below for a note about which argument would be used)
+begins with a
+.B \- ,
+all of these debugging flags will be set, resulting in massive amounts
+of output.
+.IP "\fB\-f\fP \fImakefile\fP"
+.Ix 0 def flags -f
+Specify a makefile to read different from the standard makefiles
+.CW Makefile "\&" (
+or
+.CW makefile ).
+.Ix 0 ref makefile default
+.Ix 0 ref makefile other
+If
+.I makefile
+is ``\-'', PMake uses the standard input. This is useful for making
+quick and dirty makefiles.\|.\|.
+.Ix 0 ref makefile "quick and dirty"
+.IP \fB\-h\fP
+.Ix 0 def flags -h
+Prints out a summary of the various flags PMake accepts. It can also
+be used to find out what level of concurrency was compiled into the
+version of PMake you are using (look at
+.B \-J
+and
+.B \-L )
+and various other information on how PMake was configured.
+.Ix 0 ref configuration
+.Ix 0 ref makefilesystem
+.IP \fB\-i\fP
+.Ix 0 def flags -i
+If you give this flag, PMake will ignore non-zero status returned
+by any of its shells. It's like placing a `\-' before all the commands
+in the makefile.
+.IP \fB\-k\fP
+.Ix 0 def flags -k
+This is similar to
+.B \-i
+in that it allows PMake to continue when it sees an error, but unlike
+.B \-i ,
+where PMake continues blithely as if nothing went wrong,
+.B \-k
+causes it to recognize the error and only continue work on those
+things that don't depend on the target, either directly or indirectly (through
+depending on something that depends on it), whose creation returned the error.
+The `k' is for ``keep going''.\|.\|.
+.Ix 0 ref target
+.IP \fB\-l\fP
+.Ix 0 def flags -l
+PMake has the ability to lock a directory against other
+people executing it in the same directory (by means of a file called
+``LOCK.make'' that it creates and checks for in the directory). This
+is a Good Thing because two people doing the same thing in the same place
+can be disastrous for the final product (too many cooks and all that).
+Whether this locking is the default is up to your system
+administrator. If locking is on,
+.B \-l
+will turn it off, and vice versa. Note that this locking will not
+prevent \fIyou\fP from invoking PMake twice in the same place \*- if
+you own the lock file, PMake will warn you about it but continue to execute.
+.IP "\fB\-m\fP \fIdirectory\fP"
+.Ix 0 def flags -m
+Tells PMake another place to search for included makefiles via the <...>
+style.  Several
+.B \-m
+options can be given to form a search path.  If this construct is used the
+default system makefile search path is completely overridden.
+To be explained in chapter 3, section 3.2.
+.Rm 2 3.2
+.IP \fB\-n\fP
+.Ix 0 def flags -n
+This flag tells PMake not to execute the commands needed to update the
+out-of-date targets in the makefile. Rather, PMake will simply print
+the commands it would have executed and exit. This is particularly
+useful for checking the correctness of a makefile. If PMake doesn't do
+what you expect it to, it's a good chance the makefile is wrong.
+.IP "\fB\-p\fP \fInumber\fP"
+.Ix 0 def flags -p
+.Ix 0 ref debugging
+This causes PMake to print its input in a reasonable form, though
+not necessarily one that would make immediate sense to anyone but me. The
+.I number
+is a bitwise-or of 1 and 2 where 1 means it should print the input
+before doing any processing and 2 says it should print it after
+everything has been re-created. Thus
+.CW "\-p 3"
+would print it twice\*-once before processing and once after (you
+might find the difference between the two interesting). This is mostly
+useful to me, but you may find it informative in some bizarre circumstances.
+.IP \fB\-q\fP
+.Ix 0 def flags -q
+If you give PMake this flag, it will not try to re-create anything. It
+will just see if anything is out-of-date and exit non-zero if so.
+.IP \fB\-r\fP
+.Ix 0 def flags -r
+When PMake starts up, it reads a default makefile that tells it what
+sort of system it's on and gives it some idea of what to do if you
+don't tell it anything. I'll tell you about it in chapter 3. If you
+give this flag, PMake won't read the default makefile.
+.IP \fB\-s\fP
+.Ix 0 def flags -s
+This causes PMake to not print commands before they're executed. It
+is the equivalent of putting an `@' before every command in the
+makefile.
+.IP \fB\-t\fP
+.Ix 0 def flags -t
+Rather than try to re-create a target, PMake will simply ``touch'' it
+so as to make it appear up-to-date. If the target didn't exist before,
+it will when PMake finishes, but if the target did exist, it will
+appear to have been updated.
+.IP \fB\-v\fP
+.Ix 0 def flags -v
+This is a mixed-compatibility flag intended to mimic the System V
+version of Make. It is the same as giving
+.B \-B ,
+and
+.B \-V
+as well as turning off directory locking. Targets can still be created
+in parallel, however. This is the mode PMake will enter if it is
+invoked either as
+.CW smake '' ``
+or
+.CW vmake ''. ``
+.IP \fB\-x\fP
+.Ix 0 def flags -x
+This tells PMake it's ok to export jobs to other machines, if they're
+available. It is used when running in Make mode, as exporting in this
+mode tends to make things run slower than if the commands were just
+executed locally.
+.IP \fB\-B\fP
+.Ix 0 ref compatibility
+.Ix 0 def flags -B
+Forces PMake to be as backwards-compatible with Make as possible while
+still being itself.
+This includes:
+.RS
+.IP \(bu 2
+Executing one shell per shell command
+.IP \(bu 2
+Expanding anything that looks even vaguely like a variable, with the
+empty string replacing any variable PMake doesn't know.
+.IP \(bu 2
+Refusing to allow you to escape a `#' with a backslash.
+.IP \(bu 2
+Permitting undefined variables on dependency lines and conditionals
+(see below). Normally this causes PMake to abort.
+.RE
+.IP \fB\-C\fP
+.Ix 0 def flags -C
+This nullifies any and all compatibility mode flags you may have given
+or implied up to the time the
+.B \-C
+is encountered. It is useful mostly in a makefile that you wrote for PMake
+to avoid bad things happening when someone runs PMake as
+.CW make '' ``
+or has things set in the environment that tell it to be compatible.
+.B \-C
+is
+.I not
+placed in the
+.CW PMAKE
+environment variable or the
+.CW .MAKEFLAGS
+or
+.CW MFLAGS
+global variables.
+.Ix 0 ref variable environment PMAKE
+.Ix 0 ref variable global .MAKEFLAGS
+.Ix 0 ref variable global MFLAGS
+.Ix 0 ref .MAKEFLAGS variable
+.Ix 0 ref MFLAGS
+.IP "\fB\-D\fP \fIvariable\fP"
+.Ix 0 def flags -D
+Allows you to define a variable to have 
+.CW 1 '' ``
+as its value.  The variable is a global variable, not a command-line
+variable. This is useful mostly for people who are used to the C
+compiler arguments and those using conditionals, which I'll get into
+in section 4.3
+.Rm 1 4.3
+.IP "\fB\-I\fP \fIdirectory\fP"
+.Ix 0 def flags -I
+Tells PMake another place to search for included makefiles. Yet
+another thing to be explained in chapter 3 (section 3.2, to be
+precise).
+.Rm 2 3.2
+.IP "\fB\-J\fP \fInumber\fP"
+.Ix 0 def flags -J
+Gives the absolute maximum number of targets to create at once on both
+local and remote machines.
+.IP "\fB\-L\fP \fInumber\fP"
+.Ix 0 def flags -L
+This specifies the maximum number of targets to create on the local
+machine at once. This may be 0, though you should be wary of doing
+this, as PMake may hang until a remote machine becomes available, if
+one is not available when it is started.
+.IP \fB\-M\fP
+.Ix 0 ref compatibility
+.Ix 0 def flags -M
+This is the flag that provides absolute, complete, full compatibility
+with Make. It still allows you to use all but a few of the features of
+PMake, but it is non-parallel. This is the mode PMake enters if you
+call it
+.CW make .'' ``
+.IP \fB\-P\fP
+.Ix 0 def flags -P
+.Ix 0 ref "output control"
+When creating targets in parallel, several shells are executing at
+once, each wanting to write its own two cent's-worth to the screen.
+This output must be captured by PMake in some way in order to prevent
+the screen from being filled with garbage even more indecipherable
+than you usually see. PMake has two ways of doing this, one of which
+provides for much cleaner output and a clear separation between the
+output of different jobs, the other of which provides a more immediate
+response so one can tell what is really happening. The former is done
+by notifying you when the creation of a target starts, capturing the
+output and transferring it to the screen all at once when the job
+finishes. The latter is done by catching the output of the shell (and
+its children) and buffering it until an entire line is received, then
+printing that line preceded by an indication of which job produced
+the output. Since I prefer this second method, it is the one used by
+default. The first method will be used if you give the
+.B \-P
+flag to PMake.
+.IP \fB\-V\fP
+.Ix 0 def flags -V
+As mentioned before, the
+.B \-V
+flag tells PMake to use Make's style of expanding variables,
+substituting the empty string for any variable it doesn't know.
+.IP \fB\-W\fP
+.Ix 0 def flags -W
+There are several times when PMake will print a message at you that is
+only a warning, i.e. it can continue to work in spite of your having
+done something silly (such as forgotten a leading tab for a shell
+command). Sometimes you are well aware of silly things you have done
+and would like PMake to stop bothering you. This flag tells it to shut
+up about anything non-fatal.
+.IP \fB\-X\fP
+.Ix 0 def flags -X
+This flag causes PMake to not attempt to export any jobs to another
+machine.
+.LP
+Several flags may follow a single `\-'. Those flags that require
+arguments take them from successive parameters. E.g.
+.DS
+pmake -fDnI server.mk DEBUG /chip2/X/server/include
+.DE
+will cause PMake to read
+.CW server.mk
+as the input makefile, define the variable
+.CW DEBUG
+as a global variable and look for included makefiles in the directory
+.CW /chip2/X/server/include .
+.xH 2 Summary
+.LP
+A makefile is made of four types of lines:
+.RS
+.IP \(bu 2
+Dependency lines
+.IP \(bu 2
+Creation commands
+.IP \(bu 2
+Variable assignments
+.IP \(bu 2
+Comments, include statements and conditional directives
+.RE
+.LP
+A dependency line is a list of one or more targets, an operator
+.CW : ', (`
+.CW :: ', `
+or
+.CW ! '), `
+and a list of zero or more sources. Sources may contain wildcards and
+certain local variables.
+.LP
+A creation command is a regular shell command preceded by a tab. In
+addition, if the first two characters after the tab (and other
+whitespace) are a combination of
+.CW @ ' `
+or
+.CW - ', `
+PMake will cause the command to not be printed (if the character is
+.CW @ ') `
+or errors from it to be ignored (if
+.CW - '). `
+A blank line, dependency line or variable assignment terminates a
+creation script. There may be only one creation script for each target
+with a
+.CW : ' `
+or
+.CW ! ' `
+operator.
+.LP
+Variables are places to store text. They may be unconditionally
+assigned-to using the
+.CW = ' `
+.Ix 0 ref =
+.Ix 0 ref variable assignment
+operator, appended-to using the
+.CW += ' `
+.Ix 0 ref +=
+.Ix 0 ref variable assignment appended
+operator, conditionally (if the variable is undefined) assigned-to
+with the
+.CW ?= ' `
+.Ix 0 ref ?=
+.Ix 0 ref variable assignment conditional
+operator, and assigned-to with variable expansion with the
+.CW := ' `
+.Ix 0 ref :=
+.Ix 0 ref variable assignment expanded
+operator. The output of a shell command may be assigned to a variable
+using the
+.CW != ' `
+.Ix 0 ref !=
+.Ix 0 ref variable assignment shell-output
+operator.  Variables may be expanded (their value inserted) by enclosing
+their name in parentheses or curly braces, preceded by a dollar sign.
+A dollar sign may be escaped with another dollar sign. Variables are
+not expanded if PMake doesn't know about them. There are seven local
+variables:
+.CW .TARGET ,
+.CW .ALLSRC ,
+.CW .OODATE ,
+.CW .PREFIX ,
+.CW .IMPSRC ,
+.CW .ARCHIVE ,
+and
+.CW .MEMBER .
+Four of them
+.CW .TARGET , (
+.CW .PREFIX ,
+.CW .ARCHIVE ,
+and
+.CW .MEMBER )
+may be used to specify ``dynamic sources.''
+.Ix 0 ref "dynamic source"
+.Ix 0 ref source dynamic
+Variables are good. Know them. Love them. Live them.
+.LP
+Debugging of makefiles is best accomplished using the
+.B \-n ,
+.B "\-d m" ,
+and
+.B "\-p 2"
+flags.
+.xH 2 Exercises
+.ce
+\s+4\fBTBA\fP\s0
+.xH 1 Short-cuts and Other Nice Things
+.LP
+Based on what I've told you so far, you may have gotten the impression
+that PMake is just a way of storing away commands and making sure you
+don't forget to compile something. Good. That's just what it is.
+However, the ways I've described have been inelegant, at best, and
+painful, at worst.
+This chapter contains things that make the
+writing of makefiles easier and the makefiles themselves shorter and
+easier to modify (and, occasionally, simpler). In this chapter, I
+assume you are somewhat more
+familiar with Sprite (or UNIX, if that's what you're using) than I did
+in chapter 2, just so you're on your toes.
+So without further ado...
+.xH 2 Transformation Rules
+.LP
+As you know, a file's name consists of two parts: a base name, which
+gives some hint as to the contents of the file, and a suffix, which
+usually indicates the format of the file.
+Over the years, as
+.UX
+has developed,
+naming conventions, with regard to suffixes, have also developed that have
+become almost as incontrovertible as Law. E.g. a file ending in
+.CW .c
+is assumed to contain C source code; one with a
+.CW .o
+suffix is assumed to be a compiled, relocatable object file that may
+be linked into any program; a file with a
+.CW .ms
+suffix is usually a text file to be processed by Troff with the \-ms
+macro package, and so on.
+One of the best aspects of both Make and PMake comes from their
+understanding of how the suffix of a file pertains to its contents and
+their ability to do things with a file based solely on its suffix. This
+ability comes from something known as a transformation rule. A
+transformation rule specifies how to change a file with one suffix
+into a file with another suffix.
+.LP
+A transformation rule looks much like a dependency line, except the
+target is made of two known suffixes stuck together. Suffixes are made
+known to PMake by placing them as sources on a dependency line whose
+target is the special target
+.CW .SUFFIXES .
+E.g.
+.DS
+\&.SUFFIXES       : .o .c
+\&.c.o            :
+        $(CC) $(CFLAGS) -c $(.IMPSRC)
+.DE
+The creation script attached to the target is used to transform a file with
+the first suffix (in this case,
+.CW .c )
+into a file with the second suffix (here,
+.CW .o ).
+In addition, the target inherits whatever attributes have been applied
+to the transformation rule.
+The simple rule given above says that to transform a C source file
+into an object file, you compile it using
+.CW cc
+with the
+.CW \-c
+flag.
+This rule is taken straight from the system makefile. Many
+transformation rules (and suffixes) are defined there, and I refer you
+to it for more examples (type
+.CW "pmake -h" '' ``
+to find out where it is).
+.LP
+There are several things to note about the transformation rule given
+above:
+.RS
+.IP 1)
+The
+.CW .IMPSRC 
+variable.
+.Ix 0 def variable local .IMPSRC
+.Ix 0 def .IMPSRC
+This variable is set to the ``implied source'' (the file from which
+the target is being created; the one with the first suffix), which, in this
+case, is the .c file.
+.IP 2)
+The
+.CW CFLAGS
+variable. Almost all of the transformation rules in the system
+makefile are set up using variables that you can alter in your
+makefile to tailor the rule to your needs. In this case, if you want
+all your C files to be compiled with the
+.B \-g
+flag, to provide information for
+.CW dbx ,
+you would set the
+.CW CFLAGS
+variable to contain
+.CW -g
+.CW "CFLAGS = -g" '') (``
+and PMake would take care of the rest.
+.RE
+.LP
+To give you a quick example, the makefile in 2.3.4 
+.Rm 3 2.3.4
+could be changed to this:
+.DS
+OBJS            = a.o b.o c.o
+program         : $(OBJS)
+        $(CC) -o $(.TARGET) $(.ALLSRC)
+$(OBJS)         : defs.h
+.DE
+The transformation rule I gave above takes the place of the 6 lines\**
+.FS
+This is also somewhat cleaner, I think, than the dynamic source
+solution presented in 2.6
+.FE
+.Rm 4 2.6
+.DS
+a.o             : a.c
+        cc -c a.c
+b.o             : b.c
+        cc -c b.c
+c.o             : c.c
+        cc -c c.c
+.DE
+.LP
+Now you may be wondering about the dependency between the
+.CW .o
+and
+.CW .c
+files \*- it's not mentioned anywhere in the new makefile. This is
+because it isn't needed: one of the effects of applying a
+transformation rule is the target comes to depend on the implied
+source. That's why it's called the implied
+.I source .
+.LP
+For a more detailed example. Say you have a makefile like this:
+.DS
+a.out           : a.o b.o
+        $(CC) $(.ALLSRC)
+.DE
+and a directory set up like this:
+.DS
+total 4
+-rw-rw-r--  1 deboor         34 Sep  7 00:43 Makefile
+-rw-rw-r--  1 deboor        119 Oct  3 19:39 a.c
+-rw-rw-r--  1 deboor        201 Sep  7 00:43 a.o
+-rw-rw-r--  1 deboor         69 Sep  7 00:43 b.c
+.DE
+While just typing
+.CW pmake '' ``
+will do the right thing, it's much more informative to type
+.CW "pmake -d s" ''. ``
+This will show you what PMake is up to as it processes the files. In
+this case, PMake prints the following:
+.DS
+Suff_FindDeps (a.out)
+	using existing source a.o
+	applying .o -> .out to "a.o"
+Suff_FindDeps (a.o)
+	trying a.c...got it
+	applying .c -> .o to "a.c"
+Suff_FindDeps (b.o)
+	trying b.c...got it
+	applying .c -> .o to "b.c"
+Suff_FindDeps (a.c)
+	trying a.y...not there
+	trying a.l...not there
+	trying a.c,v...not there
+	trying a.y,v...not there
+	trying a.l,v...not there
+Suff_FindDeps (b.c)
+	trying b.y...not there
+	trying b.l...not there
+	trying b.c,v...not there
+	trying b.y,v...not there
+	trying b.l,v...not there
+--- a.o ---
+cc  -c a.c
+--- b.o ---
+cc  -c b.c
+--- a.out ---
+cc a.o b.o
+.DE
+.LP
+.CW Suff_FindDeps
+is the name of a function in PMake that is called to check for implied
+sources for a target using transformation rules.
+The transformations it tries are, naturally
+enough, limited to the ones that have been defined (a transformation
+may be defined multiple times, by the way, but only the most recent
+one will be used). You will notice, however, that there is a definite
+order to the suffixes that are tried. This order is set by the
+relative positions of the suffixes on the
+.CW .SUFFIXES
+line \*- the earlier a suffix appears, the earlier it is checked as
+the source of a transformation. Once a suffix has been defined, the
+only way to change its position in the pecking order is to remove all
+the suffixes (by having a
+.CW .SUFFIXES
+dependency line with no sources) and redefine them in the order you
+want. (Previously-defined transformation rules will be automatically
+redefined as the suffixes they involve are re-entered.)
+.LP
+Another way to affect the search order is to make the dependency
+explicit. In the above example,
+.CW a.out
+depends on
+.CW a.o
+and
+.CW b.o .
+Since a transformation exists from
+.CW .o
+to
+.CW .out ,
+PMake uses that, as indicated by the
+.CW "using existing source a.o" '' ``
+message.
+.LP
+The search for a transformation starts from the suffix of the target
+and continues through all the defined transformations, in the order
+dictated by the suffix ranking, until an existing file with the same
+base (the target name minus the suffix and any leading directories) is
+found. At that point, one or more transformation rules will have been
+found to change the one existing file into the target.
+.LP
+For example, ignoring what's in the system makefile for now, say you
+have a makefile like this:
+.DS
+\&.SUFFIXES       : .out .o .c .y .l
+\&.l.c            :
+        lex $(.IMPSRC)
+        mv lex.yy.c $(.TARGET)
+\&.y.c            :
+        yacc $(.IMPSRC)
+        mv y.tab.c $(.TARGET)
+\&.c.o            :
+        cc -c $(.IMPSRC)
+\&.o.out          :
+        cc -o $(.TARGET) $(.IMPSRC)
+.DE
+and the single file
+.CW jive.l .
+If you were to type
+.CW "pmake -rd ms jive.out" ,'' ``
+you would get the following output for
+.CW jive.out :
+.DS
+Suff_FindDeps (jive.out)
+	trying jive.o...not there
+	trying jive.c...not there
+	trying jive.y...not there
+	trying jive.l...got it
+	applying .l -> .c to "jive.l"
+	applying .c -> .o to "jive.c"
+	applying .o -> .out to "jive.o"
+.DE
+and this is why: PMake starts with the target
+.CW jive.out ,
+figures out its suffix
+.CW .out ) (
+and looks for things it can transform to a
+.CW .out
+file. In this case, it only finds
+.CW .o ,
+so it looks for the file
+.CW jive.o .
+It fails to find it, so it looks for transformations into a
+.CW .o
+file. Again it has only one choice:
+.CW .c .
+So it looks for
+.CW jive.c
+and, as you know, fails to find it. At this point it has two choices:
+it can create the
+.CW .c
+file from either a
+.CW .y
+file or a
+.CW .l
+file. Since
+.CW .y
+came first on the
+.CW .SUFFIXES
+line, it checks for
+.CW jive.y
+first, but can't find it, so it looks for
+.CW jive.l
+and, lo and behold, there it is.
+At this point, it has defined a transformation path as follows:
+.CW .l
+\(->
+.CW .c
+\(->
+.CW .o
+\(->
+.CW .out
+and applies the transformation rules accordingly. For completeness,
+and to give you a better idea of what PMake actually did with this
+three-step transformation, this is what PMake printed for the rest of
+the process:
+.DS
+Suff_FindDeps (jive.o)
+	using existing source jive.c
+	applying .c -> .o to "jive.c"
+Suff_FindDeps (jive.c)
+	using existing source jive.l
+	applying .l -> .c to "jive.l"
+Suff_FindDeps (jive.l)
+Examining jive.l...modified 17:16:01 Oct 4, 1987...up-to-date
+Examining jive.c...non-existent...out-of-date
+--- jive.c ---
+lex jive.l
+\&.\|.\|. meaningless lex output deleted .\|.\|.
+mv lex.yy.c jive.c
+Examining jive.o...non-existent...out-of-date
+--- jive.o ---
+cc -c jive.c
+Examining jive.out...non-existent...out-of-date
+--- jive.out ---
+cc -o jive.out jive.o
+.DE
+.LP
+One final question remains: what does PMake do with targets that have
+no known suffix? PMake simply pretends it actually has a known suffix
+and searches for transformations accordingly.
+The suffix it chooses is the source for the
+.CW .NULL
+.Ix 0 ref .NULL
+target mentioned later. In the system makefile, 
+.CW .out
+is chosen as the ``null suffix''
+.Ix 0 def suffix null
+.Ix 0 def "null suffix"
+because most people use PMake to create programs. You are, however,
+free and welcome to change it to a suffix of your own choosing.
+The null suffix is ignored, however, when PMake is in compatibility
+mode (see chapter 4).
+.xH 2 Including Other Makefiles
+.Ix 0 def makefile inclusion
+.Rd 2
+.LP
+Just as for programs, it is often useful to extract certain parts of a
+makefile into another file and just include it in other makefiles
+somehow. Many compilers allow you say something like
+.DS
+#include "defs.h"
+.DE
+to include the contents of
+.CW defs.h
+in the source file. PMake allows you to do the same thing for
+makefiles, with the added ability to use variables in the filenames.
+An include directive in a makefile looks either like this:
+.DS
+#include <file>
+.DE
+or this
+.DS
+#include "file"
+.DE
+The difference between the two is where PMake searches for the file:
+the first way, PMake will look for
+the file only in the system makefile directory (or directories)
+(to find out what that directory is, give PMake the
+.B \-h
+flag).
+.Ix 0 ref flags -h
+The system makefile directory search path can be overridden via the
+.B \-m
+option.
+.Ix 0 ref flags -m
+For files in double-quotes, the search is more complex:
+.RS
+.IP 1)
+The directory of the makefile that's including the file.
+.IP 2)
+The current directory (the one in which you invoked PMake).
+.IP 3)
+The directories given by you using
+.B \-I
+flags, in the order in which you gave them.
+.IP 4)
+Directories given by
+.CW .PATH
+dependency lines (see chapter 4).
+.IP 5)
+The system makefile directory.
+.RE
+.LP
+in that order.
+.LP
+You are free to use PMake variables in the filename\*-PMake will
+expand them before searching for the file. You must specify the
+searching method with either angle brackets or double-quotes
+.I outside
+of a variable expansion. I.e. the following
+.DS
+SYSTEM	= <command.mk>
+
+#include $(SYSTEM)
+.DE
+won't work.
+.xH 2 Saving Commands
+.LP
+.Ix 0 def ...
+There may come a time when you will want to save certain commands to
+be executed when everything else is done. For instance: you're
+making several different libraries at one time and you want to create the
+members in parallel. Problem is,
+.CW ranlib
+is another one of those programs that can't be run more than once in
+the same directory at the same time (each one creates a file called
+.CW __.SYMDEF
+into which it stuffs information for the linker to use. Two of them
+running at once will overwrite each other's file and the result will
+be garbage for both parties). You might want a way to save the ranlib
+commands til the end so they can be run one after the other, thus
+keeping them from trashing each other's file. PMake allows you to do
+this by inserting an ellipsis (``.\|.\|.'') as a command between
+commands to be run at once and those to be run later.
+.LP
+So for the
+.CW ranlib
+case above, you might do this:
+.Rd 5
+.DS
+lib1.a          : $(LIB1OBJS)
+        rm -f $(.TARGET)
+        ar cr $(.TARGET) $(.ALLSRC)
+        ...
+        ranlib $(.TARGET)
+
+lib2.a          : $(LIB2OBJS)
+        rm -f $(.TARGET)
+        ar cr $(.TARGET) $(.ALLSRC)
+        ...
+        ranlib $(.TARGET)
+.DE
+.Ix 0 ref variable local .TARGET
+.Ix 0 ref variable local .ALLSRC
+This would save both
+.DS
+ranlib $(.TARGET)
+.DE
+commands until the end, when they would run one after the other
+(using the correct value for the
+.CW .TARGET
+variable, of course).
+.LP
+Commands saved in this manner are only executed if PMake manages to
+re-create everything without an error.
+.xH 2 Target Attributes
+.LP
+PMake allows you to give attributes to targets by means of special
+sources. Like everything else PMake uses, these sources begin with a
+period and are made up of all upper-case letters. There are various
+reasons for using them, and I will try to give examples for most of
+them. Others you'll have to find uses for yourself. Think of it as ``an
+exercise for the reader.'' By placing one (or more) of these as a source on a
+dependency line, you are ``marking the target(s) with that
+attribute.'' That's just the way I phrase it, so you know.
+.LP
+Any attributes given as sources for a transformation rule are applied
+to the target of the transformation rule when the rule is applied.
+.Ix 0 def attributes
+.Ix 0 ref source
+.Ix 0 ref target
+.nr pw 12
+.IP .DONTCARE \n(pw
+.Ix 0 def attributes .DONTCARE
+.Ix 0 def .DONTCARE
+If a target is marked with this attribute and PMake can't figure out
+how to create it, it will ignore this fact and assume the file isn't
+really needed or actually exists and PMake just can't find it. This may prove
+wrong, but the error will be noted later on, not when PMake tries to create
+the target so marked. This attribute also prevents PMake from
+attempting to touch the target if it is given the
+.B \-t
+flag.
+.Ix 0 ref flags -t
+.IP .EXEC \n(pw
+.Ix 0 def attributes .EXEC
+.Ix 0 def .EXEC
+This attribute causes its shell script to be executed while having no
+effect on targets that depend on it. This makes the target into a sort
+of subroutine.  An example. Say you have some LISP files that need to
+be compiled and loaded into a LISP process. To do this, you echo LISP
+commands into a file and execute a LISP with this file as its input
+when everything's done. Say also that you have to load other files
+from another system before you can compile your files and further,
+that you don't want to go through the loading and dumping unless one
+of
+.I your
+files has changed. Your makefile might look a little bit
+like this (remember, this is an educational example, and don't worry
+about the
+.CW COMPILE
+rule, all will soon become clear, grasshopper):
+.DS
+system          : init a.fasl b.fasl c.fasl
+        for i in $(.ALLSRC);
+        do
+                echo -n '(load "' >> input
+                echo -n ${i} >> input
+                echo '")' >> input
+        done
+        echo '(dump "$(.TARGET)")' >> input
+        lisp < input
+
+a.fasl          : a.l init COMPILE
+b.fasl          : b.l init COMPILE
+c.fasl          : c.l init COMPILE
+COMPILE         : .USE
+        echo '(compile "$(.ALLSRC)")' >> input
+init            : .EXEC
+        echo '(load-system)' > input
+.DE
+.Ix 0 ref .USE
+.Ix 0 ref attributes .USE
+.Ix 0 ref variable local .ALLSRC
+.IP "\&"
+.CW .EXEC
+sources, don't appear in the local variables of targets that depend on
+them (nor are they touched if PMake is given the
+.B \-t
+flag).
+.Ix 0 ref flags -t
+Note that all the rules, not just that for
+.CW system ,
+include
+.CW init
+as a source. This is because none of the other targets can be made
+until
+.CW init
+has been made, thus they depend on it.
+.IP .EXPORT \n(pw
+.Ix 0 def attributes .EXPORT
+.Ix 0 def .EXPORT
+This is used to mark those targets whose creation should be sent to
+another machine if at all possible. This may be used by some
+exportation schemes if the exportation is expensive. You should ask
+your system administrator if it is necessary.
+.IP .EXPORTSAME \n(pw
+.Ix 0 def attributes .EXPORTSAME
+.Ix 0 def .EXPORTSAME
+Tells the export system that the job should be exported to a machine
+of the same architecture as the current one. Certain operations (e.g.
+running text through
+.CW nroff )
+can be performed the same on any architecture (CPU and
+operating system type), while others (e.g. compiling a program with
+.CW cc )
+must be performed on a machine with the same architecture. Not all
+export systems will support this attribute.
+.IP .IGNORE \n(pw
+.Ix 0 def attributes .IGNORE
+.Ix 0 def .IGNORE attribute
+Giving a target the
+.CW .IGNORE
+attribute causes PMake to ignore errors from any of the target's commands, as
+if they all had `\-' before them.
+.IP .INVISIBLE \n(pw
+.Ix 0 def attributes .INVISIBLE
+.Ix 0 def .INVISIBLE
+This allows you to specify one target as a source for another without
+the one affecting the other's local variables. Useful if, say, you
+have a makefile that creates two programs, one of which is used to
+create the other, so it must exist before the other is created. You
+could say
+.DS
+prog1           : $(PROG1OBJS) prog2 MAKEINSTALL
+prog2           : $(PROG2OBJS) .INVISIBLE MAKEINSTALL
+.DE
+where
+.CW MAKEINSTALL
+is some complex .USE rule (see below) that depends on the
+.Ix 0 ref .USE
+.CW .ALLSRC
+variable containing the right things. Without the
+.CW .INVISIBLE
+attribute for
+.CW prog2 ,
+the
+.CW MAKEINSTALL
+rule couldn't be applied. This is not as useful as it should be, and
+the semantics may change (or the whole thing go away) in the
+not-too-distant future.
+.IP .JOIN \n(pw
+.Ix 0 def attributes .JOIN
+.Ix 0 def .JOIN
+This is another way to avoid performing some operations in parallel
+while permitting everything else to be done so. Specifically it
+forces the target's shell script to be executed only if one or more of the
+sources was out-of-date. In addition, the target's name,
+in both its
+.CW .TARGET
+variable and all the local variables of any target that depends on it,
+is replaced by the value of its
+.CW .ALLSRC
+variable.
+As an example, suppose you have a program that has four libraries that
+compile in the same directory along with, and at the same time as, the
+program. You again have the problem with
+.CW ranlib
+that I mentioned earlier, only this time it's more severe: you
+can't just put the ranlib off to the end since the program
+will need those libraries before it can be re-created. You can do
+something like this:
+.DS
+program         : $(OBJS) libraries
+        cc -o $(.TARGET) $(.ALLSRC)
+
+libraries       : lib1.a lib2.a lib3.a lib4.a .JOIN
+        ranlib $(.OODATE)
+.DE
+.Ix 0 ref variable local .TARGET
+.Ix 0 ref variable local .ALLSRC
+.Ix 0 ref variable local .OODATE
+.Ix 0 ref .TARGET
+.Ix 0 ref .ALLSRC
+.Ix 0 ref .OODATE
+In this case, PMake will re-create the
+.CW $(OBJS)
+as necessary, along with
+.CW lib1.a ,
+.CW lib2.a ,
+.CW lib3.a
+and
+.CW lib4.a .
+It will then execute
+.CW ranlib
+on any library that was changed and set
+.CW program 's
+.CW .ALLSRC
+variable to contain what's in
+.CW $(OBJS)
+followed by
+.CW "lib1.a lib2.a lib3.a lib4.a" .'' ``
+In case you're wondering, it's called
+.CW .JOIN
+because it joins together different threads of the ``input graph'' at
+the target marked with the attribute.
+Another aspect of the .JOIN attribute is it keeps the target from
+being created if the
+.B \-t
+flag was given.
+.Ix 0 ref flags -t
+.IP .MAKE \n(pw
+.Ix 0 def attributes .MAKE
+.Ix 0 def .MAKE
+The
+.CW .MAKE
+attribute marks its target as being a recursive invocation of PMake.
+This forces PMake to execute the script associated with the target (if
+it's out-of-date) even if you gave the
+.B \-n
+or
+.B \-t
+flag. By doing this, you can start at the top of a system and type
+.DS
+pmake -n
+.DE
+and have it descend the directory tree (if your makefiles are set up
+correctly), printing what it would have executed if you hadn't
+included the
+.B \-n
+flag.
+.IP .NOEXPORT \n(pw
+.Ix 0 def attributes .NOEXPORT
+.Ix 0 def .NOEXPORT attribute
+If possible, PMake will attempt to export the creation of all targets to
+another machine (this depends on how PMake was configured). Sometimes,
+the creation is so simple, it is pointless to send it to another
+machine. If you give the target the
+.CW .NOEXPORT
+attribute, it will be run locally, even if you've given PMake the
+.B "\-L 0"
+flag.
+.IP .NOTMAIN \n(pw
+.Ix 0 def attributes .NOTMAIN
+.Ix 0 def .NOTMAIN
+Normally, if you do not specify a target to make in any other way,
+PMake will take the first target on the first dependency line of a
+makefile as the target to create. That target is known as the ``Main
+Target'' and is labeled as such if you print the dependencies out
+using the
+.B \-p
+flag.
+.Ix 0 ref flags -p
+Giving a target this attribute tells PMake that the target is
+definitely
+.I not
+the Main Target.
+This allows you to place targets in an included makefile and
+have PMake create something else by default.
+.IP .PRECIOUS \n(pw
+.Ix 0 def attributes .PRECIOUS
+.Ix 0 def .PRECIOUS attribute
+When PMake is interrupted (you type control-C at the keyboard), it
+will attempt to clean up after itself by removing any half-made
+targets. If a target has the
+.CW .PRECIOUS
+attribute, however, PMake will leave it alone. An additional side
+effect of the `::' operator is to mark the targets as
+.CW .PRECIOUS .
+.Ix 0 ref operator double-colon
+.Ix 0 ref ::
+.IP .SILENT \n(pw
+.Ix 0 def attributes .SILENT
+.Ix 0 def .SILENT attribute
+Marking a target with this attribute keeps its commands from being
+printed when they're executed, just as if they had an `@' in front of them.
+.IP .USE \n(pw
+.Ix 0 def attributes .USE
+.Ix 0 def .USE
+By giving a target this attribute, you turn it into PMake's equivalent
+of a macro. When the target is used as a source for another target,
+the other target acquires the commands, sources and attributes (except
+.CW .USE )
+of the source.
+If the target already has commands, the
+.CW .USE
+target's commands are added to the end. If more than one .USE-marked
+source is given to a target, the rules are applied sequentially.
+.IP "\&" \n(pw
+The typical .USE rule (as I call them) will use the sources of the
+target to which it is applied (as stored in the
+.CW .ALLSRC
+variable for the target) as its ``arguments,'' if you will.
+For example, you probably noticed that the commands for creating
+.CW lib1.a
+and
+.CW lib2.a
+in the example in section 3.3
+.Rm 5 3.3
+were exactly the same. You can use the
+.CW .USE
+attribute to eliminate the repetition, like so:
+.DS
+lib1.a          : $(LIB1OBJS) MAKELIB
+lib2.a          : $(LIB2OBJS) MAKELIB
+
+MAKELIB         : .USE
+        rm -f $(.TARGET)
+        ar cr $(.TARGET) $(.ALLSRC)
+        ...
+        ranlib $(.TARGET)
+.DE
+.Ix 0 ref variable local .TARGET
+.Ix 0 ref variable local .ALLSRC
+.IP "\&" \n(pw
+Several system makefiles (not to be confused with The System Makefile)
+make use of these  .USE rules to make your
+life easier (they're in the default, system makefile directory...take a look).
+Note that the .USE rule source itself
+.CW MAKELIB ) (
+does not appear in any of the targets's local variables.
+There is no limit to the number of times I could use the
+.CW MAKELIB
+rule. If there were more libraries, I could continue with
+.CW "lib3.a : $(LIB3OBJS) MAKELIB" '' ``
+and so on and so forth.
+.xH 2 Special Targets
+.LP
+As there were in Make, so there are certain targets that have special
+meaning to PMake. When you use one on a dependency line, it is the
+only target that may appear on the left-hand-side of the operator.
+.Ix 0 ref target
+.Ix 0 ref operator
+As for the attributes and variables, all the special targets
+begin with a period and consist of upper-case letters only.
+I won't describe them all in detail because some of them are rather
+complex and I'll describe them in more detail than you'll want in
+chapter 4.
+The targets are as follows:
+.nr pw 10
+.IP .BEGIN \n(pw
+.Ix 0 def .BEGIN
+Any commands attached to this target are executed before anything else
+is done. You can use it for any initialization that needs doing.
+.IP .DEFAULT \n(pw
+.Ix 0 def .DEFAULT
+This is sort of a .USE rule for any target (that was used only as a
+source) that PMake can't figure out any other way to create. It's only
+``sort of'' a .USE rule because only the shell script attached to the
+.CW .DEFAULT
+target is used. The
+.CW .IMPSRC
+variable of a target that inherits
+.CW .DEFAULT 's
+commands is set to the target's own name.
+.Ix 0 ref .IMPSRC
+.Ix 0 ref variable local .IMPSRC
+.IP .END \n(pw
+.Ix 0 def .END
+This serves a function similar to
+.CW .BEGIN ,
+in that commands attached to it are executed once everything has been
+re-created (so long as no errors occurred). It also serves the extra
+function of being a place on which PMake can hang commands you put off
+to the end. Thus the script for this target will be executed before
+any of the commands you save with the ``.\|.\|.''.
+.Ix 0 ref ...
+.IP .EXPORT \n(pw
+The sources for this target are passed to the exportation system compiled
+into PMake. Some systems will use these sources to configure
+themselves. You should ask your system administrator about this.
+.IP .IGNORE \n(pw
+.Ix 0 def .IGNORE target
+.Ix 0 ref .IGNORE attribute
+.Ix 0 ref attributes .IGNORE
+This target marks each of its sources with the
+.CW .IGNORE
+attribute. If you don't give it any sources, then it is like
+giving the
+.B \-i
+flag when you invoke PMake \*- errors are ignored for all commands.
+.Ix 0 ref flags -i
+.IP .INCLUDES \n(pw
+.Ix 0 def .INCLUDES target
+.Ix 0 def variable global .INCLUDES
+.Ix 0 def .INCLUDES variable
+The sources for this target are taken to be suffixes that indicate a
+file that can be included in a program source file.
+The suffix must have already been declared with
+.CW .SUFFIXES
+(see below).
+Any suffix so marked will have the directories on its search path
+(see
+.CW .PATH ,
+below) placed in the
+.CW .INCLUDES
+variable, each preceded by a
+.B \-I
+flag. This variable can then be used as an argument for the compiler
+in the normal fashion. The
+.CW .h
+suffix is already marked in this way in the system makefile.
+.Ix 0 ref makefilesystem
+E.g. if you have
+.DS
+\&.SUFFIXES       : .bitmap
+\&.PATH.bitmap    : /usr/local/X/lib/bitmaps
+\&.INCLUDES       : .bitmap
+.DE
+PMake will place
+.CW "-I/usr/local/X/lib/bitmaps" '' ``
+in the
+.CW .INCLUDES
+variable and you can then say
+.DS
+cc $(.INCLUDES) -c xprogram.c
+.DE
+(Note: the
+.CW .INCLUDES
+variable is not actually filled in until the entire makefile has been read.)
+.IP .INTERRUPT \n(pw
+.Ix 0 def .INTERRUPT
+When PMake is interrupted,
+it will execute the commands in the script for this target, if it
+exists.
+.IP .LIBS \n(pw
+.Ix 0 def .LIBS target
+.Ix 0 def .LIBS variable
+.Ix 0 def variable global .LIBS
+This does for libraries what
+.CW .INCLUDES
+does for include files, except the flag used is
+.B \-L ,
+as required by those linkers that allow you to tell them where to find
+libraries. The variable used is
+.CW .LIBS .
+Be forewarned that PMake may not have been compiled to do this if the
+linker on your system doesn't accept the
+.B \-L
+flag, though the
+.CW .LIBS
+variable will always be defined once the makefile has been read.
+.IP .MAIN \n(pw
+.Ix 0 def .MAIN
+If you didn't give a target (or targets) to create when you invoked
+PMake, it will take the sources of this target as the targets to
+create.
+.IP .MAKEFLAGS \n(pw
+.Ix 0 def .MAKEFLAGS target
+This target provides a way for you to always specify flags for PMake
+when the makefile is used. The flags are just as they would be typed
+to the shell (except you can't use shell variables unless they're in
+the environment),
+though the
+.B \-f
+and
+.B \-r
+flags have no effect.
+.IP .NULL \n(pw
+.Ix 0 def .NULL
+.Ix 0 ref suffix null
+.Ix 0 ref "null suffix"
+This allows you to specify what suffix PMake should pretend a file has
+if, in fact, it has no known suffix. Only one suffix may be so
+designated. The last source on the dependency line is the suffix that
+is used (you should, however, only give one suffix.\|.\|.).
+.IP .PATH \n(pw
+.Ix 0 def .PATH
+If you give sources for this target, PMake will take them as
+directories in which to search for files it cannot find in the current
+directory. If you give no sources, it will clear out any directories
+added to the search path before. Since the effects of this all get
+very complex, I'll leave it til chapter four to give you a complete
+explanation.
+.IP .PATH\fIsuffix\fP \n(pw
+.Ix 0 ref .PATH
+This does a similar thing to
+.CW .PATH ,
+but it does it only for files with the given suffix. The suffix must
+have been defined already. Look at
+.B "Search Paths"
+(section 4.1)
+.Rm 6 4.1
+for more information.
+.IP .PRECIOUS \n(pw
+.Ix 0 def .PRECIOUS target
+.Ix 0 ref .PRECIOUS attribute
+.Ix 0 ref attributes .PRECIOUS
+Similar to
+.CW .IGNORE ,
+this gives the
+.CW .PRECIOUS
+attribute to each source on the dependency line, unless there are no
+sources, in which case the
+.CW .PRECIOUS
+attribute is given to every target in the file.
+.IP .RECURSIVE \n(pw
+.Ix 0 def .RECURSIVE
+.Ix 0 ref attributes .MAKE
+.Ix 0 ref .MAKE
+This target applies the
+.CW .MAKE
+attribute to all its sources. It does nothing if you don't give it any sources.
+.IP .SHELL \n(pw
+.Ix 0 def .SHELL
+PMake is not constrained to only using the Bourne shell to execute
+the commands you put in the makefile. You can tell it some other shell
+to use with this target. Check out
+.B "A Shell is a Shell is a Shell"
+(section 4.4)
+.Rm 7 4.4
+for more information.
+.IP .SILENT \n(pw
+.Ix 0 def .SILENT target
+.Ix 0 ref .SILENT attribute
+.Ix 0 ref attributes .SILENT
+When you use
+.CW .SILENT
+as a target, it applies the
+.CW .SILENT
+attribute to each of its sources. If there are no sources on the
+dependency line, then it is as if you gave PMake the
+.B \-s
+flag and no commands will be echoed.
+.IP .SUFFIXES \n(pw
+.Ix 0 def .SUFFIXES
+This is used to give new file suffixes for PMake to handle. Each
+source is a suffix PMake should recognize. If you give a
+.CW .SUFFIXES
+dependency line with no sources, PMake will forget about all the
+suffixes it knew (this also nukes the null suffix).
+For those targets that need to have suffixes defined, this is how you do it.
+.LP
+In addition to these targets, a line of the form
+.DS
+\fIattribute\fP : \fIsources\fP
+.DE
+applies the
+.I attribute
+to all the targets listed as
+.I sources .
+.xH 2 Modifying Variable Expansion
+.LP
+.Ix 0 def variable expansion modified
+.Ix 0 ref variable expansion
+.Ix 0 def variable modifiers
+Variables need not always be expanded verbatim. PMake defines several
+modifiers that may be applied to a variable's value before it is
+expanded. You apply a modifier by placing it after the variable name
+with a colon between the two, like so:
+.DS
+${\fIVARIABLE\fP:\fImodifier\fP}
+.DE
+Each modifier is a single character followed by something specific to
+the modifier itself.
+You may apply as many modifiers as you want \*- each one is applied to
+the result of the previous and is separated from the previous by
+another colon.
+.LP
+There are seven ways to modify a variable's expansion, most of which
+come from the C shell variable modification characters:
+.RS
+.IP "M\fIpattern\fP"
+.Ix 0 def :M
+.Ix 0 def modifier match
+This is used to select only those words (a word is a series of
+characters that are neither spaces nor tabs) that match the given
+.I pattern .
+The pattern is a wildcard pattern like that used by the shell, where
+.CW *
+means 0 or more characters of any sort;
+.CW ?
+is any single character;
+.CW [abcd]
+matches any single character that is either `a', `b', `c' or `d'
+(there may be any number of characters between the brackets);
+.CW [0-9]
+matches any single character that is between `0' and `9' (i.e. any
+digit. This form may be freely mixed with the other bracket form), and
+`\\' is used to escape any of the characters `*', `?', `[' or `:',
+leaving them as regular characters to match themselves in a word.
+For example, the system makefile
+.CW <makedepend.mk>
+uses
+.CW "$(CFLAGS:M-[ID]*)" '' ``
+to extract all the
+.CW \-I
+and
+.CW \-D
+flags that would be passed to the C compiler. This allows it to
+properly locate include files and generate the correct dependencies.
+.IP "N\fIpattern\fP"
+.Ix 0 def :N
+.Ix 0 def modifier nomatch
+This is identical to
+.CW :M
+except it substitutes all words that don't match the given pattern.
+.IP "S/\fIsearch-string\fP/\fIreplacement-string\fP/[g]"
+.Ix 0 def :S
+.Ix 0 def modifier substitute
+Causes the first occurrence of
+.I search-string
+in the variable to be replaced by
+.I replacement-string ,
+unless the
+.CW g
+flag is given at the end, in which case all occurrences of the string
+are replaced. The substitution is performed on each word in the
+variable in turn. If 
+.I search-string
+begins with a
+.CW ^ ,
+the string must match starting at the beginning of the word. If
+.I search-string
+ends with a
+.CW $ ,
+the string must match to the end of the word (these two may be
+combined to force an exact match). If a backslash precedes these two
+characters, however, they lose their special meaning. Variable
+expansion also occurs in the normal fashion inside both the
+.I search-string
+and the
+.I replacement-string ,
+.B except
+that a backslash is used to prevent the expansion of a
+.CW $ ,
+not another dollar sign, as is usual.
+Note that
+.I search-string
+is just a string, not a pattern, so none of the usual
+regular-expression/wildcard characters have any special meaning save
+.CW ^
+and
+.CW $ .
+In the replacement string,
+the
+.CW &
+character is replaced by the
+.I search-string
+unless it is preceded by a backslash.
+You are allowed to use any character except
+colon or exclamation point to separate the two strings. This so-called
+delimiter character may be placed in either string by preceding it
+with a backslash.
+.IP T
+.Ix 0 def :T
+.Ix 0 def modifier tail
+Replaces each word in the variable expansion by its last
+component (its ``tail''). For example, given
+.DS
+OBJS = ../lib/a.o b /usr/lib/libm.a
+TAILS = $(OBJS:T)
+.DE
+the variable
+.CW TAILS
+would expand to
+.CW "a.o b libm.a" .'' ``
+.IP H
+.Ix 0 def :H
+.Ix 0 def modifier head
+This is similar to
+.CW :T ,
+except that every word is replaced by everything but the tail (the
+``head''). Using the same definition of
+.CW OBJS ,
+the string
+.CW "$(OBJS:H)" '' ``
+would expand to
+.CW "../lib /usr/lib" .'' ``
+Note that the final slash on the heads is removed and
+anything without a head is replaced by the empty string.
+.IP E
+.Ix 0 def :E
+.Ix 0 def modifier extension
+.Ix 0 def modifier suffix
+.Ix 0 ref suffix "variable modifier"
+.CW :E
+replaces each word by its suffix (``extension''). So
+.CW "$(OBJS:E)" '' ``
+would give you
+.CW ".o .a" .'' ``
+.IP R
+.Ix 0 def :R
+.Ix 0 def modifier root
+.Ix 0 def modifier base
+This replaces each word by everything but the suffix (the ``root'' of
+the word).
+.CW "$(OBJS:R)" '' ``
+expands to ``
+.CW "../lib/a b /usr/lib/libm" .''
+.RE
+.LP
+In addition, the System V style of substitution is also supported.
+This looks like:
+.DS
+$(\fIVARIABLE\fP:\fIsearch-string\fP=\fIreplacement\fP)
+.DE
+It must be the last modifier in the chain. The search is anchored at
+the end of each word, so only suffixes or whole words may be replaced.
+.xH 2 More on Debugging
+.xH 2 More Exercises
+.IP (3.1)
+You've got a set programs, each of which is created from its own
+assembly-language source file (suffix
+.CW .asm ).
+Each program can be assembled into two versions, one with error-checking
+code assembled in and one without. You could assemble them into files
+with different suffixes
+.CW .eobj \& (
+and
+.CW .obj ,
+for instance), but your linker only understands files that end in
+.CW .obj .
+To top it all off, the final executables
+.I must
+have the suffix
+.CW .exe .
+How can you still use transformation rules to make your life easier
+(Hint: assume the error-checking versions have
+.CW ec
+tacked onto their prefix)?
+.IP (3.2)
+Assume, for a moment or two, you want to perform a sort of
+``indirection'' by placing the name of a variable into another one,
+then you want to get the value of the first by expanding the second
+somehow. Unfortunately, PMake doesn't allow constructs like
+.DS I
+$($(FOO))
+.DE
+What do you do? Hint: no further variable expansion is performed after
+modifiers are applied, thus if you cause a $ to occur in the
+expansion, that's what will be in the result.
+.xH 1 PMake for Gods
+.LP
+This chapter is devoted to those facilities in PMake that allow you to
+do a great deal in a makefile with very little work, as well as do
+some things you couldn't do in Make without a great deal of work (and
+perhaps the use of other programs). The problem with these features,
+is they must be handled with care, or you will end up with a mess.
+.LP
+Once more, I assume a greater familiarity with
+.UX
+or Sprite than I did in the previous two chapters.
+.xH 2 Search Paths
+.Rd 6
+.LP
+PMake supports the dispersal of files into multiple directories by
+allowing you to specify places to look for sources with
+.CW .PATH
+targets in the makefile. The directories you give as sources for these
+targets make up a ``search path.'' Only those files used exclusively
+as sources are actually sought on a search path, the assumption being
+that anything listed as a target in the makefile can be created by the
+makefile and thus should be in the current directory.
+.LP
+There are two types of search paths
+in PMake: one is used for all types of files (including included
+makefiles) and is specified with a plain
+.CW .PATH
+target (e.g.
+.CW ".PATH : RCS" ''), ``
+while the other is specific to a certain type of file, as indicated by
+the file's suffix. A specific search path is indicated by immediately following
+the
+.CW .PATH
+with the suffix of the file. For instance
+.DS
+\&.PATH.h         : /sprite/lib/include /sprite/att/lib/include
+.DE
+would tell PMake to look in the directories
+.CW /sprite/lib/include
+and
+.CW /sprite/att/lib/include
+for any files whose suffix is
+.CW .h .
+.LP
+The current directory is always consulted first to see if a file
+exists. Only if it cannot be found there are the directories in the
+specific search path, followed by those in the general search path,
+consulted.
+.LP
+A search path is also used when expanding wildcard characters. If the
+pattern has a recognizable suffix on it, the path for that suffix will
+be used for the expansion. Otherwise the default search path is employed.
+.LP
+When a file is found in some directory other than the current one, all
+local variables that would have contained the target's name
+.CW .ALLSRC , (
+and
+.CW .IMPSRC )
+will instead contain the path to the file, as found by PMake.
+Thus if you have a file
+.CW ../lib/mumble.c
+and a makefile
+.DS
+\&.PATH.c         : ../lib
+mumble          : mumble.c
+        $(CC) -o $(.TARGET) $(.ALLSRC)
+.DE
+the command executed to create
+.CW mumble
+would be
+.CW "cc -o mumble ../lib/mumble.c" .'' ``
+(As an aside, the command in this case isn't strictly necessary, since
+it will be found using transformation rules if it isn't given. This is because
+.CW .out
+is the null suffix by default and a transformation exists from
+.CW .c
+to
+.CW .out .
+Just thought I'd throw that in.)
+.LP
+If a file exists in two directories on the same search path, the file
+in the first directory on the path will be the one PMake uses. So if
+you have a large system spread over many directories, it would behoove
+you to follow a naming convention that avoids such conflicts.
+.LP
+Something you should know about the way search paths are implemented
+is that each directory is read, and its contents cached, exactly once
+\&\*- when it is first encountered \*- so any changes to the
+directories while PMake is running will not be noted when searching
+for implicit sources, nor will they be found when PMake attempts to
+discover when the file was last modified, unless the file was created in the
+current directory. While people have suggested that PMake should read
+the directories each time, my experience suggests that the caching seldom
+causes problems. In addition, not caching the directories slows things
+down enormously because of PMake's attempts to apply transformation
+rules through non-existent files \*- the number of extra file-system
+searches is truly staggering, especially if many files without
+suffixes are used and the null suffix isn't changed from
+.CW .out .
+.xH 2 Archives and Libraries
+.LP
+.UX
+and Sprite allow you to merge files into an archive using the
+.CW ar
+command. Further, if the files are relocatable object files, you can
+run
+.CW ranlib
+on the archive and get yourself a library that you can link into any
+program you want. The main problem with archives is they double the
+space you need to store the archived files, since there's one copy in
+the archive and one copy out by itself. The problem with libraries is
+you usually think of them as
+.CW -lm
+rather than
+.CW /usr/lib/libm.a
+and the linker thinks they're out-of-date if you so much as look at
+them.
+.LP
+PMake solves the problem with archives by allowing you to tell it to
+examine the files in the archives (so you can remove the individual
+files without having to regenerate them later). To handle the problem
+with libraries, PMake adds an additional way of deciding if a library
+is out-of-date:
+.IP \(bu 2
+If the table of contents is older than the library, or is missing, the
+library is out-of-date.
+.LP
+A library is any target that looks like
+.CW \-l name'' ``
+or that ends in a suffix that was marked as a library using the
+.CW .LIBS
+target.
+.CW .a
+is so marked in the system makefile.
+.LP
+Members of an archive are specified as
+``\fIarchive\fP(\fImember\fP[ \fImember\fP...])''.
+Thus
+.CW libdix.a(window.o) '' ``'
+specifies the file
+.CW window.o
+in the archive
+.CW libdix.a .
+You may also use wildcards to specify the members of the archive. Just
+remember that most the wildcard characters will only find 
+.I existing
+files.
+.LP
+A file that is a member of an archive is treated specially. If the
+file doesn't exist, but it is in the archive, the modification time
+recorded in the archive is used for the file when determining if the
+file is out-of-date. When figuring out how to make an archived member target
+(not the file itself, but the file in the archive \*- the
+\fIarchive\fP(\fImember\fP) target), special care is
+taken with the transformation rules, as follows:
+.IP \(bu 2
+\&\fIarchive\fP(\fImember\fP) is made to depend on \fImember\fP.
+.IP \(bu 2
+The transformation from the \fImember\fP's suffix to the
+\fIarchive\fP's suffix is applied to the \fIarchive\fP(\fImember\fP) target.
+.IP \(bu 2
+The \fIarchive\fP(\fImember\fP)'s
+.CW .TARGET
+variable is set to the name of the \fImember\fP if \fImember\fP is
+actually a target, or the path to the member file if \fImember\fP is
+only a source.
+.IP \(bu 2
+The
+.CW .ARCHIVE
+variable for the \fIarchive\fP(\fImember\fP) target is set to the name
+of the \fIarchive\fP.
+.Ix 0 def variable local .ARCHIVE
+.Ix 0 def .ARCHIVE
+.IP \(bu 2
+The
+.CW .MEMBER
+variable is set to the actual string inside the parentheses. In most
+cases, this will be the same as the
+.CW .TARGET
+variable.
+.Ix 0 def variable local .MEMBER
+.Ix 0 def .MEMBER
+.IP \(bu 2
+The \fIarchive\fP(\fImember\fP)'s place in the local variables of the
+targets that depend on it is taken by the value of its
+.CW .TARGET
+variable.
+.LP
+Thus, a program library could be created with the following makefile:
+.DS
+\&.o.a            :
+        ...
+        rm -f $(.TARGET:T)
+OBJS            = obj1.o obj2.o obj3.o
+libprog.a       : libprog.a($(OBJS))
+        ar cru $(.TARGET) $(.OODATE)
+        ranlib $(.TARGET)
+.DE
+This will cause the three object files to be compiled (if the
+corresponding source files were modified after the object file or, if
+that doesn't exist, the archived object file), the out-of-date ones
+archived in
+.CW libprog.a ,
+a table of contents placed in the archive and the newly-archived
+object files to be removed.
+.LP
+All this is used in the 
+.CW makelib.mk
+system makefile to create a single library with ease. This makefile
+looks like this:
+.DS
+.SM
+#
+# Rules for making libraries. The object files that make up the library
+# are removed once they are archived.
+#
+# To make several libraries in parallel, you should define the variable
+# "many_libraries". This will serialize the invocations of ranlib.
+#
+# To use, do something like this:
+#
+# OBJECTS = <files in the library>
+#
+# fish.a: fish.a($(OBJECTS)) MAKELIB
+#
+#
+
+#ifndef _MAKELIB_MK
+_MAKELIB_MK	=
+
+#include	<po.mk>
+
+\&.po.a .o.a	:
+	...
+	rm -f $(.MEMBER)
+
+ARFLAGS		?= crl
+
+#
+# Re-archive the out-of-date members and recreate the library's table of
+# contents using ranlib. If many_libraries is defined, put the ranlib
+# off til the end so many libraries can be made at once.
+#
+MAKELIB		: .USE .PRECIOUS
+	ar $(ARFLAGS) $(.TARGET) $(.OODATE)
+#ifndef no_ranlib
+# ifdef many_libraries
+	...
+# endif many_libraries
+	ranlib $(.TARGET)
+#endif no_ranlib
+
+#endif _MAKELIB_MK
+.DE
+.xH 2 On the Condition...
+.Rd 1
+.LP
+Like the C compiler before it, PMake allows you to configure the makefile,
+based on the current environment, using conditional statements. A
+conditional looks like this:
+.DS
+#if \fIboolean expression\fP
+\fIlines\fP
+#elif \fIanother boolean expression\fP
+\fImore lines\fP
+#else
+\fIstill more lines\fP
+#endif
+.DE
+They may be nested to a maximum depth of 30 and may occur anywhere
+(except in a comment, of course). The
+.CW # '' ``
+must the very first character on the line.
+.LP
+Each
+.I "boolean expression"
+is made up of terms that look like function calls, the standard C
+boolean operators
+.CW && ,
+.CW || ,
+and
+.CW ! ,
+and the standard relational operators
+.CW == ,
+.CW != ,
+.CW > ,
+.CW >= ,
+.CW < ,
+and
+.CW <= ,
+with
+.CW ==
+and
+.CW !=
+being overloaded to allow string comparisons as well.
+.CW &&
+represents logical AND;
+.CW ||
+is logical OR and
+.CW !
+is logical NOT.  The arithmetic and string operators take precedence
+over all three of these operators, while NOT takes precedence over
+AND, which takes precedence over OR.  This precedence may be
+overridden with parentheses, and an expression may be parenthesized to
+your heart's content.  Each term looks like a call on one of four
+functions:
+.nr pw 9
+.Ix 0 def make
+.Ix 0 def conditional make
+.Ix 0 def if make
+.IP make \n(pw
+The syntax is
+.CW make( \fItarget\fP\c
+.CW )
+where
+.I target
+is a target in the makefile. This is true if the given target was
+specified on the command line, or as the source for a
+.CW .MAIN
+target (note that the sources for
+.CW .MAIN
+are only used if no targets were given on the command line).
+.IP defined \n(pw
+.Ix 0 def defined
+.Ix 0 def conditional defined
+.Ix 0 def if defined
+The syntax is
+.CW defined( \fIvariable\fP\c
+.CW )
+and is true if
+.I variable
+is defined. Certain variables are defined in the system makefile that
+identify the system on which PMake is being run.
+.IP exists \n(pw
+.Ix 0 def exists
+.Ix 0 def conditional exists
+.Ix 0 def if exists
+The syntax is
+.CW exists( \fIfile\fP\c
+.CW )
+and is true if the file can be found on the global search path (i.e.
+that defined by
+.CW .PATH
+targets, not by
+.CW .PATH \fIsuffix\fP
+targets).
+.IP empty \n(pw
+.Ix 0 def empty
+.Ix 0 def conditional empty
+.Ix 0 def if empty
+This syntax is much like the others, except the string inside the
+parentheses is of the same form as you would put between parentheses
+when expanding a variable, complete with modifiers and everything. The
+function returns true if the resulting string is empty (NOTE: an undefined
+variable in this context will cause at the very least a warning
+message about a malformed conditional, and at the worst will cause the
+process to stop once it has read the makefile. If you want to check
+for a variable being defined or empty, use the expression
+.CW !defined( \fIvar\fP\c ``
+.CW ") || empty(" \fIvar\fP\c
+.CW ) ''
+as the definition of
+.CW ||
+will prevent the
+.CW empty()
+from being evaluated and causing an error, if the variable is
+undefined). This can be used to see if a variable contains a given
+word, for example:
+.DS
+#if !empty(\fIvar\fP:M\fIword\fP)
+.DE
+.LP
+The arithmetic and string operators may only be used to test the value
+of a variable. The lefthand side must contain the variable expansion,
+while the righthand side contains either a string, enclosed in
+double-quotes, or a number. The standard C numeric conventions (except
+for specifying an octal number) apply to both sides. E.g.
+.DS
+#if $(OS) == 4.3
+
+#if $(MACHINE) == "sun3"
+
+#if $(LOAD_ADDR) < 0xc000
+.DE
+are all valid conditionals. In addition, the numeric value of a
+variable can be tested as a boolean as follows:
+.DS
+#if $(LOAD)
+.DE
+would see if
+.CW LOAD
+contains a non-zero value and
+.DS
+#if !$(LOAD)
+.DE
+would test if
+.CW LOAD
+contains a zero value.
+.LP
+In addition to the bare
+.CW #if ,'' ``
+there are other forms that apply one of the first two functions to each
+term. They are as follows:
+.DS
+	ifdef	\fRdefined\fP
+	ifndef	\fR!defined\fP
+	ifmake	\fRmake\fP
+	ifnmake	\fR!make\fP
+.DE
+There are also the ``else if'' forms:
+.CW elif ,
+.CW elifdef ,
+.CW elifndef ,
+.CW elifmake ,
+and
+.CW elifnmake .
+.LP
+For instance, if you wish to create two versions of a program, one of which
+is optimized (the production version) and the other of which is for debugging
+(has symbols for dbx), you have two choices: you can create two
+makefiles, one of which uses the
+.CW \-g
+flag for the compilation, while the other uses the
+.CW \-O
+flag, or you can use another target (call it
+.CW debug )
+to create the debug version. The construct below will take care of
+this for you. I have also made it so defining the variable
+.CW DEBUG
+(say with
+.CW "pmake -D DEBUG" )
+will also cause the debug version to be made.
+.DS
+#if defined(DEBUG) || make(debug)
+CFLAGS		+= -g
+#else
+CFLAGS		+= -O
+#endif
+.DE
+There are, of course, problems with this approach. The most glaring
+annoyance is that if you want to go from making a debug version to
+making a production version, you have to remove all the object files,
+or you will get some optimized and some debug versions in the same
+program. Another annoyance is you have to be careful not to make two
+targets that ``conflict'' because of some conditionals in the
+makefile. For instance
+.DS
+#if make(print)
+FORMATTER	= ditroff -Plaser_printer
+#endif
+#if make(draft)
+FORMATTER	= nroff -Pdot_matrix_printer
+#endif
+.DE
+would wreak havoc if you tried
+.CW "pmake draft print" '' ``
+since you would use the same formatter for each target. As I said,
+this all gets somewhat complicated.
+.xH 2 A Shell is a Shell is a Shell
+.Rd 7
+.LP
+In normal operation, the Bourne Shell (better known as
+.CW sh '') ``
+is used to execute the commands to re-create targets. PMake also allows you
+to specify a different shell for it to use when executing these
+commands. There are several things PMake must know about the shell you
+wish to use. These things are specified as the sources for the
+.CW .SHELL
+.Ix 0 ref .SHELL
+.Ix 0 ref target .SHELL
+target by keyword, as follows:
+.IP "\fBpath=\fP\fIpath\fP"
+PMake needs to know where the shell actually resides, so it can
+execute it. If you specify this and nothing else, PMake will use the
+last component of the path and look in its table of the shells it
+knows and use the specification it finds, if any. Use this if you just
+want to use a different version of the Bourne or C Shell (yes, PMake knows
+how to use the C Shell too).
+.IP "\fBname=\fP\fIname\fP"
+This is the name by which the shell is to be known. It is a single
+word and, if no other keywords are specified (other than
+.B path ),
+it is the name by which PMake attempts to find a specification for
+it (as mentioned above). You can use this if you would just rather use
+the C Shell than the Bourne Shell
+.CW ".SHELL: name=csh" '' (``
+will do it).
+.IP "\fBquiet=\fP\fIecho-off command\fP"
+As mentioned before, PMake actually controls whether commands are
+printed by introducing commands into the shell's input stream. This
+keyword, and the next two, control what those commands are. The
+.B quiet
+keyword is the command used to turn echoing off. Once it is turned
+off, echoing is expected to remain off until the echo-on command is given.
+.IP "\fBecho=\fP\fIecho-on command\fP"
+The command PMake should give to turn echoing back on again.
+.IP "\fBfilter=\fP\fIprinted echo-off command\fP"
+Many shells will echo the echo-off command when it is given. This
+keyword tells PMake in what format the shell actually prints the
+echo-off command. Wherever PMake sees this string in the shell's
+output, it will delete it and any following whitespace, up to and
+including the next newline. See the example at the end of this section
+for more details.
+.IP "\fBechoFlag=\fP\fIflag to turn echoing on\fP"
+Unless a target has been marked
+.CW .SILENT ,
+PMake wants to start the shell running with echoing on. To do this, it
+passes this flag to the shell as one of its arguments. If either this
+or the next flag begins with a `\-', the flags will be passed to the
+shell as separate arguments. Otherwise, the two will be concatenated
+(if they are used at the same time, of course).
+.IP "\fBerrFlag=\fP\fIflag to turn error checking on\fP"
+Likewise, unless a target is marked
+.CW .IGNORE ,
+PMake wishes error-checking to be on from the very start. To this end,
+it will pass this flag to the shell as an argument. The same rules for
+an initial `\-' apply as for the
+.B echoFlag .
+.IP "\fBcheck=\fP\fIcommand to turn error checking on\fP"
+Just as for echo-control, error-control is achieved by inserting
+commands into the shell's input stream. This is the command to make
+the shell check for errors. It also serves another purpose if the
+shell doesn't have error-control as commands, but I'll get into that
+in a minute. Again, once error checking has been turned on, it is
+expected to remain on until it is turned off again.
+.IP "\fBignore=\fP\fIcommand to turn error checking off\fP"
+This is the command PMake uses to turn error checking off. It has
+another use if the shell doesn't do error-control, but I'll tell you
+about that.\|.\|.\|now.
+.IP "\fBhasErrCtl=\fP\fIyes or no\fP"
+This takes a value that is either
+.B yes
+or
+.B no .
+Now you might think that the existence of the
+.B check
+and
+.B ignore
+keywords would be enough to tell PMake if the shell can do
+error-control, but you'd be wrong. If
+.B hasErrCtl
+is
+.B yes ,
+PMake uses the check and ignore commands in a straight-forward manner.
+If this is
+.B no ,
+however, their use is rather different. In this case, the check
+command is used as a template, in which the string
+.B %s
+is replaced by the command that's about to be executed, to produce a
+command for the shell that will echo the command to be executed. The
+ignore command is also used as a template, again with
+.B %s
+replaced by the command to be executed, to produce a command that will
+execute the command to be executed and ignore any error it returns.
+When these strings are used as templates, you must provide newline(s)
+.CW \en '') (``
+in the appropriate place(s).
+.LP
+The strings that follow these keywords may be enclosed in single or
+double quotes (the quotes will be stripped off) and may contain the
+usual C backslash-characters (\en is newline, \er is return, \eb is
+backspace, \e' escapes a single-quote inside single-quotes, \e"
+escapes a double-quote inside double-quotes). Now for an example.
+.LP
+This is actually the contents of the
+.CW <shx.mk>
+system makefile, and causes PMake to use the Bourne Shell in such a
+way that each command is printed as it is executed. That is, if more
+than one command is given on a line, each will be printed separately.
+Similarly, each time the body of a loop is executed, the commands
+within that loop will be printed, etc. The specification runs like
+this:
+.DS
+#
+# This is a shell specification to have the Bourne shell echo
+# the commands just before executing them, rather than when it reads
+# them. Useful if you want to see how variables are being expanded, etc.
+#
+\&.SHELL 	: path=/bin/sh \e
+	quiet="set -" \e
+	echo="set -x" \e
+	filter="+ set - " \e
+	echoFlag=x \e
+	errFlag=e \e
+	hasErrCtl=yes \e
+	check="set -e" \e
+	ignore="set +e"
+.DE
+.LP
+It tells PMake the following:
+.Bp
+The shell is located in the file
+.CW /bin/sh .
+It need not tell PMake that the name of the shell is
+.CW sh 
+as PMake can figure that out for itself (it's the last component of
+the path).
+.Bp
+The command to stop echoing is
+.CW "set -" .
+.Bp
+The command to start echoing is
+.CW "set -x" .
+.Bp
+When the echo off command is executed, the shell will print
+.CW "+ set - " 
+(The `+' comes from using the
+.CW \-x
+flag (rather than the
+.CW \-v
+flag PMake usually uses)). PMake will remove all occurrences of this
+string from the output, so you don't notice extra commands you didn't
+put there.
+.Bp
+The flag the Bourne Shell will take to start echoing in this way is
+the
+.CW \-x
+flag. The Bourne Shell will only take its flag arguments concatenated
+as its first argument, so neither this nor the
+.B errFlag
+specification begins with a \-.
+.Bp
+The flag to use to turn error-checking on from the start is
+.CW \-e .
+.Bp
+The shell can turn error-checking on and off, and the commands to do
+so are
+.CW "set +e"
+and
+.CW "set -e" ,
+respectively.
+.LP
+I should note that this specification is for Bourne Shells that are
+not part of Berkeley
+.UX ,
+as shells from Berkeley don't do error control. You can get a similar
+effect, however, by changing the last three lines to be:
+.DS
+	hasErrCtl=no \e
+	check="echo \e"+ %s\e"\en" \e
+	ignore="sh -c '%s || exit 0\en"
+.DE
+.LP
+This will cause PMake to execute the two commands
+.DS
+echo "+ \fIcmd\fP"
+sh -c '\fIcmd\fP || true'
+.DE
+for each command for which errors are to be ignored. (In case you are
+wondering, the thing for
+.CW ignore
+tells the shell to execute another shell without error checking on and
+always exit 0, since the
+.B ||
+causes the
+.CW "exit 0"
+to be executed only if the first command exited non-zero, and if the
+first command exited zero, the shell will also exit zero, since that's
+the last command it executed).
+.xH 2 Compatibility
+.Ix 0 ref compatibility
+.LP
+There are three (well, 3 \(12) levels of backwards-compatibility built
+into PMake.  Most makefiles will need none at all. Some may need a
+little bit of work to operate correctly when run in parallel. Each
+level encompasses the previous levels (e.g.
+.B \-B
+(one shell per command) implies
+.B \-V )
+The three levels are described in the following three sections.
+.xH 3 DEFCON 3 \*- Variable Expansion
+.Ix 0 ref compatibility
+.LP
+As noted before, PMake will not expand a variable unless it knows of a
+value for it. This can cause problems for makefiles that expect to
+leave variables undefined except in special circumstances (e.g. if
+more flags need to be passed to the C compiler or the output from a
+text processor should be sent to a different printer). If the
+variables are enclosed in curly braces
+.CW ${PRINTER} ''), (``
+the shell will let them pass. If they are enclosed in parentheses,
+however, the shell will declare a syntax error and the make will come
+to a grinding halt.
+.LP
+You have two choices: change the makefile to define the variables
+(their values can be overridden on the command line, since that's
+where they would have been set if you used Make, anyway) or always give the
+.B \-V
+flag (this can be done with the
+.CW .MAKEFLAGS
+target, if you want).
+.xH 3 DEFCON 2 \*- The Number of the Beast
+.Ix 0 ref compatibility
+.LP
+Then there are the makefiles that expect certain commands, such as
+changing to a different directory, to not affect other commands in a
+target's creation script. You can solve this is either by going
+back to executing one shell per command (which is what the
+.B \-B
+flag forces PMake to do), which slows the process down a good bit and
+requires you to use semicolons and escaped newlines for shell constructs, or
+by changing the makefile to execute the offending command(s) in a subshell
+(by placing the line inside parentheses), like so:
+.DS
+install :: .MAKE
+	(cd src; $(.PMAKE) install)
+	(cd lib; $(.PMAKE) install)
+	(cd man; $(.PMAKE) install)
+.DE
+.Ix 0 ref operator double-colon
+.Ix 0 ref variable global .PMAKE
+.Ix 0 ref .PMAKE
+.Ix 0 ref .MAKE
+.Ix 0 ref attribute .MAKE
+This will always execute the three makes (even if the
+.B \-n
+flag was given) because of the combination of the ``::'' operator and
+the
+.CW .MAKE
+attribute. Each command will change to the proper directory to perform
+the install, leaving the main shell in the directory in which it started.
+.xH 3 "DEFCON 1 \*- Imitation is the Not the Highest Form of Flattery"
+.Ix 0 ref compatibility
+.LP
+The final category of makefile is the one where every command requires
+input, the dependencies are incompletely specified, or you simply
+cannot create more than one target at a time, as mentioned earlier. In
+addition, you may not have the time or desire to upgrade the makefile
+to run smoothly with PMake. If you are the conservative sort, this is
+the compatibility mode for you. It is entered either by giving PMake
+the
+.B \-M
+flag (for Make), or by executing PMake as
+.CW make .'' ``
+In either case, PMake performs things exactly like Make (while still
+supporting most of the nice new features PMake provides). This
+includes:
+.IP \(bu 2
+No parallel execution.
+.IP \(bu 2
+Targets are made in the exact order specified by the makefile. The
+sources for each target are made in strict left-to-right order, etc.
+.IP \(bu 2
+A single Bourne shell is used to execute each command, thus the
+shell's
+.CW $$
+variable is useless, changing directories doesn't work across command
+lines, etc.
+.IP \(bu 2
+If no special characters exist in a command line, PMake will break the
+command into words itself and execute the command directly, without
+executing a shell first. The characters that cause PMake to execute a
+shell are:
+.CW # ,
+.CW = ,
+.CW | ,
+.CW ^ ,
+.CW ( ,
+.CW ) ,
+.CW { ,
+.CW } ,
+.CW ; ,
+.CW & ,
+.CW < ,
+.CW > ,
+.CW * ,
+.CW ? ,
+.CW [ ,
+.CW ] ,
+.CW : ,
+.CW $ ,
+.CW ` ,
+and
+.CW \e .
+You should notice that these are all the characters that are given
+special meaning by the shell (except
+.CW '
+and
+.CW " ,
+which PMake deals with all by its lonesome).
+.IP \(bu 2
+The use of the null suffix is turned off.
+.Ix 0 ref "null suffix"
+.Ix 0 ref suffix null
+.xH 2 The Way Things Work
+.LP
+When PMake reads the makefile, it parses sources and targets into
+nodes in a graph. The graph is directed only in the sense that PMake
+knows which way is up. Each node contains not only links to all its
+parents and children (the nodes that depend on it and those on which
+it depends, respectively), but also a count of the number of its
+children that have already been processed.
+.LP
+The most important thing to know about how PMake uses this graph is
+that the traversal is breadth-first and occurs in two passes.
+.LP
+After PMake has parsed the makefile, it begins with the nodes the user
+has told it to make (either on the command line, or via a 
+.CW .MAIN
+target, or by the target being the first in the file not labeled with
+the
+.CW .NOTMAIN
+attribute) placed in a queue. It continues to take the node off the
+front of the queue, mark it as something that needs to be made, pass
+the node to 
+.CW Suff_FindDeps
+(mentioned earlier) to find any implicit sources for the node, and
+place all the node's children that have yet to be marked at the end of
+the queue. If any of the children is a
+.CW .USE
+rule, its attributes are applied to the parent, then its commands are
+appended to the parent's list of commands and its children are linked
+to its parent. The parent's unmade children counter is then decremented
+(since the
+.CW .USE
+node has been processed). You will note that this allows a
+.CW .USE
+node to have children that are
+.CW .USE
+nodes and the rules will be applied in sequence.
+If the node has no children, it is placed at the end of
+another queue to be examined in the second pass. This process
+continues until the first queue is empty.
+.LP
+At this point, all the leaves of the graph are in the examination
+queue. PMake removes the node at the head of the queue and sees if it
+is out-of-date. If it is, it is passed to a function that will execute
+the commands for the node asynchronously. When the commands have
+completed, all the node's parents have their unmade children counter
+decremented and, if the counter is then 0, they are placed on the
+examination queue. Likewise, if the node is up-to-date. Only those
+parents that were marked on the downward pass are processed in this
+way. Thus PMake traverses the graph back up to the nodes the user
+instructed it to create. When the examination queue is empty and no
+shells are running to create a target, PMake is finished.
+.LP
+Once all targets have been processed, PMake executes the commands
+attached to the
+.CW .END
+target, either explicitly or through the use of an ellipsis in a shell
+script. If there were no errors during the entire process but there
+are still some targets unmade (PMake keeps a running count of how many
+targets are left to be made), there is a cycle in the graph. PMake does
+a depth-first traversal of the graph to find all the targets that
+weren't made and prints them out one by one.
+.xH 1 Answers to Exercises
+.IP (3.1)
+This is something of a trick question, for which I apologize. The
+trick comes from the UNIX definition of a suffix, which PMake doesn't
+necessarily share. You will have noticed that all the suffixes used in
+this tutorial (and in UNIX in general) begin with a period
+.CW .ms , (
+.CW .c ,
+etc.). Now, PMake's idea of a suffix is more like English's: it's the
+characters at the end of a word. With this in mind, one possible
+.Ix 0 def suffix
+solution to this problem goes as follows:
+.DS I
+\&.SUFFIXES       : ec.exe .exe ec.obj .obj .asm
+ec.objec.exe .obj.exe :
+        link -o $(.TARGET) $(.IMPSRC)
+\&.asmec.obj      :
+        asm -o $(.TARGET) -DDO_ERROR_CHECKING $(.IMPSRC)
+\&.asm.obj        :
+        asm -o $(.TARGET) $(.IMPSRC)
+.DE
+.IP (3.2)
+The trick to this one lies in the ``:='' variable-assignment operator
+and the ``:S'' variable-expansion modifier. 
+.Ix 0 ref variable assignment expanded
+.Ix 0 ref variable expansion modified
+.Ix 0 ref modifier substitute
+.Ix 0 ref :S
+.Ix 0 ref :=
+Basically what you want is to take the pointer variable, so to speak,
+and transform it into an invocation of the variable at which it
+points. You might try something like
+.DS I
+$(PTR:S/^/\e$(/:S/$/))
+.DE
+which places
+.CW $( '' ``
+at the front of the variable name and
+.CW ) '' ``
+at the end, thus transforming
+.CW VAR ,'' ``
+for example, into
+.CW $(VAR) ,'' ``
+which is just what we want. Unfortunately (as you know if you've tried
+it), since, as it says in the hint, PMake does no further substitution
+on the result of a modified expansion, that's \fIall\fP you get. The
+solution is to make use of ``:='' to place that string into yet
+another variable, then invoke the other variable directly:
+.DS I
+*PTR            := $(PTR:S/^/\e$(/:S/$/)/)
+.DE
+You can then use
+.CW $(*PTR) '' ``
+to your heart's content.
+.de Gp
+.XP
+\&\fB\\$1:\fP
+..
+.xH 1 Glossary of Jargon
+.Gp "attribute"
+A property given to a target that causes PMake to treat it differently.
+.Gp "command script"
+The lines immediately following a dependency line that specify
+commands to execute to create each of the targets on the dependency
+line. Each line in the command script must begin with a tab.
+.Gp "command-line variable"
+A variable defined in an argument when PMake is first executed.
+Overrides all assignments to the same variable name in the makefile.
+.Gp "conditional"
+A construct much like that used in C that allows a makefile to be
+configured on the fly based on the local environment, or on what is being
+made by that invocation of PMake.
+.Gp "creation script"
+Commands used to create a target. See ``command script.''
+.Gp "dependency"
+The relationship between a source and a target. This comes in three
+flavors, as indicated by the operator between the target and the
+source. `:' gives a straight time-wise dependency (if the target is
+older than the source, the target is out-of-date), while `!' provides
+simply an ordering and always considers the target out-of-date. `::'
+is much like `:', save it creates multiple instances of a target each
+of which depends on its own list of sources.
+.Gp "dynamic source"
+This refers to a source that has a local variable invocation in it. It
+allows a single dependency line to specify a different source for each
+target on the line.
+.Gp "global variable"
+Any variable defined in a makefile. Takes precedence over variables
+defined in the environment, but not over command-line or local variables.
+.Gp "input graph"
+What PMake constructs from a makefile. Consists of nodes made of the
+targets in the makefile, and the links between them (the
+dependencies). The links are directed (from source to target) and
+there may not be any cycles (loops) in the graph.
+.Gp "local variable"
+A variable defined by PMake visible only in a target's shell script.
+There are seven local variables, not all of which are defined for
+every target:
+.CW .TARGET ,
+.CW .ALLSRC ,
+.CW .OODATE ,
+.CW .PREFIX ,
+.CW .IMPSRC ,
+.CW .ARCHIVE ,
+and
+.CW .MEMBER .
+.CW .TARGET ,
+.CW .PREFIX ,
+.CW .ARCHIVE ,
+and 
+.CW .MEMBER
+may be used on dependency lines to create ``dynamic sources.''
+.Gp "makefile"
+A file that describes how a system is built. If you don't know what it
+is after reading this tutorial.\|.\|.\|.
+.Gp "modifier"
+A letter, following a colon, used to alter how a variable is expanded.
+It has no effect on the variable itself.
+.Gp "operator"
+What separates a source from a target (on a dependency line) and specifies
+the relationship between the two. There are three:
+.CW : ', `
+.CW :: ', `
+and
+.CW ! '. `
+.Gp "search path"
+A list of directories in which a file should be sought. PMake's view
+of the contents of directories in a search path does not change once
+the makefile has been read. A file is sought on a search path only if
+it is exclusively a source.
+.Gp "shell"
+A program to which commands are passed in order to create targets.
+.Gp "source"
+Anything to the right of an operator on a dependency line. Targets on
+the dependency line are usually created from the sources.
+.Gp "special target"
+A target that causes PMake to do special things when it's encountered.
+.Gp "suffix"
+The tail end of a file name. Usually begins with a period,
+.CW .c
+or
+.CW .ms ,
+e.g.
+.Gp "target"
+A word to the left of the operator on a dependency line. More
+generally, any file that PMake might create. A file may be (and often
+is) both a target and a source (what it is depends on how PMake is
+looking at it at the time \*- sort of like the wave/particle duality
+of light, you know).
+.Gp "transformation rule"
+A special construct in a makefile that specifies how to create a file
+of one type from a file of another, as indicated by their suffixes.
+.Gp "variable expansion"
+The process of substituting the value of a variable for a reference to
+it. Expansion may be altered by means of modifiers.
+.Gp "variable"
+A place in which to store text that may be retrieved later. Also used
+to define the local environment. Conditionals exist that test whether
+a variable is defined or not.
+.bp
+.\" Output table of contents last, with an entry for the index, making
+.\" sure to save and restore the last real page number for the index...
+.nr @n \n(PN+1
+.\" We are not generating an index
+.\" .XS \n(@n
+.\" Index
+.\" .XE
+.nr %% \n%
+.PX
+.nr % \n(%%
diff --git a/share/doc/psd/18.gprof/Makefile b/share/doc/psd/18.gprof/Makefile
index 1097072..2a5bed1 100644
--- a/share/doc/psd/18.gprof/Makefile
+++ b/share/doc/psd/18.gprof/Makefile
@@ -10,6 +10,5 @@ USE_SOELIM=
 USE_PIC=
 USE_TBL=
 USE_EQN=
-SRCDIR=		${.CURDIR}/../../../../usr.bin/gprof/PSD.doc
 
 .include <bsd.doc.mk>
diff --git a/share/doc/psd/18.gprof/abstract.me b/share/doc/psd/18.gprof/abstract.me
new file mode 100644
index 0000000..28e8066
--- /dev/null
+++ b/share/doc/psd/18.gprof/abstract.me
@@ -0,0 +1,66 @@
+.\" Copyright (c) 1982, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)abstract.me	8.1 (Berkeley) 6/8/93
+.\"
+.sp 1
+\fB\s+2gprof: a Call Graph Execution Profiler\s-2\fP\**
+.(f
+\**This work was supported by grant MCS80-05144
+from the National Science Foundation.
+.)f
+.sp 1
+by
+\fISusan L. Graham\fP
+\fIPeter B. Kessler\fP
+\fIMarshall K. McKusick\fP
+.sp 1
+Computer Science Division
+Electrical Engineering and Computer Science Department
+University of California, Berkeley
+Berkeley, California 94720
+.ce 0
+.sp 1
+.sp 0.5i
+.sh 0 "Abstract"
+.pp
+Large complex programs are composed of many small routines
+that implement abstractions for the routines that call them.
+To be useful, an execution profiler must attribute
+execution time in a way that is significant for the 
+logical structure of a program
+as well as for its textual decomposition.
+This data must then be displayed to the user
+in a convenient and informative way.
+The \fBgprof\fP profiler 
+accounts for the running time of called routines
+in the running time of the routines that call them.
+The design and use of this profiler is described.
diff --git a/share/doc/psd/18.gprof/gathering.me b/share/doc/psd/18.gprof/gathering.me
new file mode 100644
index 0000000..17130c3
--- /dev/null
+++ b/share/doc/psd/18.gprof/gathering.me
@@ -0,0 +1,231 @@
+.\" Copyright (c) 1982, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)gathering.me	8.1 (Berkeley) 6/8/93
+.\"
+.sh 1 "Gathering Profile Data"
+.pp
+Routine calls or statement executions can be measured by having a
+compiler augment the code at strategic points.
+The additions can be inline increments to counters [Knuth71]
+[Satterthwaite72] [Joy79] or calls to
+monitoring routines [Unix].
+The counter increment overhead is low, and is suitable for
+profiling statements.
+A call of the monitoring routine has an overhead comparable with a
+call of a regular routine, and is therefore only suited
+to profiling on a routine by routine basis.
+However, the monitoring routine solution has certain advantages.
+Whatever counters are needed by the monitoring routine can be
+managed by the monitoring routine itself, rather than being
+distributed around the code.
+In particular, a monitoring routine can easily be called from separately
+compiled programs.
+In addition, different monitoring routines can be linked into the
+program
+being measured
+to assemble different profiling data without having to
+change the compiler or recompile the program.
+We have exploited this approach;
+our compilers for C, Fortran77, and Pascal can insert calls to a
+monitoring routine in the prologue for each routine.
+Use of the monitoring routine requires no planning on part of a
+programmer other than to request that augmented routine
+prologues be produced during compilation.
+.pp
+We are interested in gathering three pieces of information during
+program execution: call counts and execution times for 
+each profiled routine, and the arcs of the dynamic call graph
+traversed by this execution of the program.
+By post-processing of this data we can build the dynamic call
+graph for this execution of the program and propagate times along
+the edges of this graph to attribute times for routines to the
+routines that invoke them.
+.pp
+Gathering of the profiling information should not greatly
+interfere with the running of the program.
+Thus, the monitoring routine must not produce trace output each
+time it is invoked.
+The volume of data thus produced would be unmanageably large,
+and the time required to record it would overwhelm the running
+time of most programs.
+Similarly, the monitoring routine can not do the analysis of
+the profiling data (e.g. assembling the call graph, propagating
+times around it, discovering cycles, etc.) during program
+execution.
+Our solution is to gather profiling data in memory during program
+execution and to condense it to a file as the profiled
+program exits.
+This file is then processed by a separate program to produce the
+listing of the profile data.
+An advantage of this approach is that the profile data for
+several executions of a program can be combined by the
+post-processing to provide a profile of many
+executions.
+.pp
+The execution time monitoring consists of three parts.
+The first part allocates and initializes the runtime monitoring data
+structures before the program begins execution.
+The second part is the monitoring routine invoked from the
+prologue of each profiled routine.
+The third part condenses the data structures and writes them
+to a file as the program terminates.
+The monitoring routine is discussed in detail in the following sections.
+.sh 2 "Execution Counts"
+.pp
+The \fBgprof\fP monitoring routine counts the number of times
+each profiled routine is called.
+The monitoring routine also records the arc in the call graph
+that activated the profiled routine.
+The count is associated with the arc in the call graph
+rather than with the routine.
+Call counts for routines can then be determined by summing the counts
+on arcs directed into that routine.
+In a machine-dependent fashion, the monitoring routine notes its
+own return address.
+This address is in the prologue of some profiled routine that is
+the destination of an arc in the dynamic call graph.
+The monitoring routine also discovers the return address for that
+routine, thus identifying the call site, or source of the arc.
+The source of the arc is in the \fIcaller\fP, and the destination is in
+the \fIcallee\fP.
+For example, if a routine A calls a routine B, A is the caller, 
+and B is the callee.
+The prologue of B will include a call to the monitoring routine
+that will note the arc from A to B and either initialize or
+increment a counter for that arc.
+.pp
+One can not afford to have the monitoring routine output tracing
+information as each arc is identified.
+Therefore, the monitoring routine maintains a table of all the
+arcs discovered, with counts of the numbers of times each is
+traversed during execution.
+This table is accessed once per routine call.
+Access to it
+must be as fast as possible so as not to overwhelm the time
+required to execute the program.
+.pp
+Our solution is to access the table through a hash table.
+We use the call site as the primary key with the callee
+address being the secondary key.
+Since each call site typically calls only one callee, we can
+reduce (usually to one) the number of minor lookups based on the callee.
+Another alternative would use the callee as the primary key and the
+call site as the secondary key.
+Such an organization has the advantage of associating callers with
+callees, at the expense of longer lookups in the monitoring
+routine.
+We are fortunate to be running in a virtual memory environment,
+and (for the sake of speed) were able to allocate enough space
+for the primary hash table to allow a one-to-one mapping from
+call site addresses to the primary hash table.
+Thus our hash function is trivial to calculate and collisions
+occur only for call sites that call multiple
+destinations (e.g. functional parameters and functional variables).
+A one level hash function using both call site and callee would
+result in an unreasonably large hash table.
+Further, the number of dynamic call sites and callees is not known during
+execution of the profiled program.
+.pp
+Not all callers and callees can be identified by the monitoring
+routine.
+Routines that were compiled without the profiling augmentations
+will not call the monitoring routine as part of their prologue,
+and thus no arcs will be recorded whose destinations are in these
+routines.
+One need not profile all the routines in a program.
+Routines that are not profiled run at full speed.
+Certain routines, notably exception handlers, are invoked by
+non-standard calling sequences.
+Thus the monitoring routine may know the destination of an arc
+(the callee),
+but find it difficult or
+impossible to determine the source of the arc (the caller).
+Often in these cases the apparent source of the arc is not a call
+site at all.
+Such anomalous invocations are declared ``spontaneous''.
+.sh 2 "Execution Times"
+.pp
+The execution times for routines can be gathered in at least two
+ways.
+One method measures the execution time of a routine by measuring
+the elapsed time from routine entry to routine exit.
+Unfortunately, time measurement is complicated on time-sharing
+systems by the time-slicing of the program.
+A second method samples the value of the program counter at some
+interval, and infers execution time from the distribution of the
+samples within the program.
+This technique is particularly suited to time-sharing systems,
+where the time-slicing can serve as the basis for sampling
+the program counter.
+Notice that, whereas the first method could provide exact timings,
+the second is inherently a statistical approximation.
+.pp
+The sampling method need not require support from the operating
+system:  all that is needed is the ability to set and respond to
+``alarm clock'' interrupts that run relative to program time.
+It is imperative that the intervals be uniform since the
+sampling of the program counter rather than the duration of the
+interval is the basis of the distribution.
+If sampling is done too often, the interruptions to sample the
+program counter will overwhelm the running of the profiled program.
+On the other hand, the program must run for enough sampled
+intervals that the distribution of the samples accurately
+represents the distribution of time for the execution of the
+program.
+As with routine call tracing, the monitoring routine can not
+afford to output information for each program counter
+sample.
+In our computing environment, the operating system can provide a
+histogram of the location of the program counter at the end of
+each clock tick (1/60th of a second) in which a program runs.
+The histogram is assembled in memory as the program runs.
+This facility is enabled by our monitoring routine.
+We have adjusted the granularity of the histogram so that
+program counter values map one-to-one onto the histogram.
+We make the simplifying assumption that all calls to a specific
+routine require the same amount of time to execute.
+This assumption may disguise that some calls
+(or worse, some call sites) always invoke a routine
+such that its execution is faster (or slower)
+than the average time for that routine.
+.pp
+When the profiled program terminates, 
+the arc table and the histogram of
+program counter samples is written to a file.
+The arc table is condensed to consist of the source and destination
+addresses of the arc and the count of the number of times the arc
+was traversed by this execution of the program.
+The recorded histogram consists of counters of the number of
+times the program counter was found to be in each of the ranges covered
+by the histogram.
+The ranges themselves are summarized as a
+lower and upper bound and a step size.
diff --git a/share/doc/psd/18.gprof/header.me b/share/doc/psd/18.gprof/header.me
new file mode 100644
index 0000000..aef606d
--- /dev/null
+++ b/share/doc/psd/18.gprof/header.me
@@ -0,0 +1,38 @@
+.\" Copyright (c) 1982, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)header.me	8.1 (Berkeley) 8/14/93
+.\"
+.\"he 'gprof''Graham, Kessler, McKusick'
+.\"fo 'Draft of \*(td''%'
+.\"ls 2
+.eh 'PSD:18-%''gprof \*- a Call Graph Execution Profiler'
+.oh 'gprof \*- A Call Graph Execution Profiler''PSD:18-%'
diff --git a/share/doc/psd/18.gprof/intro.me b/share/doc/psd/18.gprof/intro.me
new file mode 100644
index 0000000..3a872b2
--- /dev/null
+++ b/share/doc/psd/18.gprof/intro.me
@@ -0,0 +1,81 @@
+.\" Copyright (c) 1982, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)intro.me	8.1 (Berkeley) 6/8/93
+.\"
+.sh 1 "Programs to be Profiled"
+.pp
+Software research environments
+normally include many large programs
+both for  production use and for experimental investigation.
+These programs are typically modular,
+in accordance with generally accepted principles
+of good program design.
+Often they consist of numerous small routines
+that implement various abstractions.
+Sometimes such large programs are written
+by one programmer 
+who has understood the requirements for
+these abstractions, and has programmed them
+appropriately.
+More frequently the program has
+had multiple authors and has
+evolved over time, changing the demands placed
+on the implementation of the abstractions without
+changing the implementation itself.
+Finally, the program may be assembled from a library
+of abstraction implementations 
+unexamined by the programmer.
+.pp
+Once a large program is executable,
+it is often desirable to increase its speed,
+especially if small portions of the program 
+are found to dominate its execution time.
+The purpose of the \fBgprof\fP profiling tool is to 
+help the user evaluate alternative implementations
+of abstractions.
+We developed this tool in response to our efforts 
+to improve a code generator we were writing [Graham82].
+.pp
+The \fBgprof\fP design takes advantage of the fact that the programs
+to be measured are large, structured and hierarchical.
+We provide a profile in which the execution time
+for a set of routines that implement an
+abstraction is collected and charged
+to that abstraction.
+The profile can be used to compare and assess the costs of
+various implementations.
+.pp
+The profiler can be linked into a program without
+special planning by the programmer.
+The overhead for using \fBgprof\fP is low;
+both in terms of added execution time and in the
+volume of profiling information recorded.
diff --git a/share/doc/psd/18.gprof/postp.me b/share/doc/psd/18.gprof/postp.me
new file mode 100644
index 0000000..d71fefb
--- /dev/null
+++ b/share/doc/psd/18.gprof/postp.me
@@ -0,0 +1,190 @@
+.\" Copyright (c) 1982, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)postp.me	8.1 (Berkeley) 6/8/93
+.\"
+.EQ
+delim $$
+gsize 11
+.EN
+.sh 1 "Post Processing"
+.pp
+Having gathered the arcs of the call graph and timing information
+for an execution of the program,
+we are interested in attributing the time for each routine to the
+routines that call it.
+We build a dynamic call graph with arcs from caller to callee,
+and propagate time from descendants to ancestors
+by topologically sorting the call graph.
+Time propagation is performed from the leaves of the
+call graph toward the roots, according to the order
+assigned by a topological numbering algorithm.
+The topological numbering ensures that
+all edges in the graph go from higher numbered nodes to lower
+numbered nodes.
+An example is given in Figure 1.
+If we propagate time from nodes in the
+order assigned by the algorithm,
+execution time can be propagated from descendants to ancestors
+after a single traversal of each arc in the call graph.
+Each parent receives some fraction of a child's time.
+Thus time is charged to the
+caller in addition to being charged to the callee.
+.(z
+.so postp1.pic
+.ce 2
+Topological ordering
+Figure 1.
+.ce 0
+.)z
+.pp
+Let $C sub e$ be the number of calls to some routine,
+$e$, and $C sub e sup r$ be the number of
+calls from a caller $r$ to a callee $e$.
+Since we are assuming each call to a routine takes the
+average amount of time for all calls to that routine,
+the caller is accountable for
+$C sub e sup r / C sub e$
+of the time spent by the callee.
+Let the $S sub e$ be the $selftime$ of a routine, $e$.
+The selftime of a routine can be determined from the
+timing information gathered during profiled program execution.
+The total time, $T sub r$, we wish to account to a routine
+$r$, is then given by the recurrence equation:
+.EQ
+T sub r ~ = ~ {S sub r} ~ + ~
+                   sum from {r ~ roman CALLS ~ e}
+                   {T sub e times {{C sub e sup r} over {C sub e}}}
+.EN
+where $r ~ roman CALLS ~ e$ is a relation showing all routines
+$e$ called by a routine $r$.
+This relation is easily available from the call graph.
+.pp
+However, if the execution contains recursive calls,
+the call graph has cycles that
+cannot be topologically sorted.
+In these cases, we discover strongly-connected
+components in the call graph,
+treat each such component as a single node,
+and then sort the resulting graph.
+We use a variation of Tarjan's strongly-connected
+components algorithm
+that discovers strongly-connected components as it is assigning
+topological order numbers [Tarjan72].
+.pp
+Time propagation within strongly connected
+components is a problem.
+For example, a self-recursive routine
+(a trivial cycle in the call graph)
+is accountable for all the time it
+uses in all its recursive instantiations.
+In our scheme, this time should be
+shared among its call graph parents.
+The arcs from a routine to itself are of interest,
+but do not participate in time propagation.
+Thus the simple equation for time propagation
+does not work within strongly connected components.
+Time is not propagated from one member of a cycle to another,
+since, by definition, this involves propagating time from a routine
+to itself.
+In addition, children of one member of a cycle
+must be considered children of all members of the cycle.
+Similarly, parents of one member of the cycle must inherit
+all members of the cycle as descendants.
+It is for these reasons that we collapse connected components.
+Our solution collects all members of a cycle together,
+summing the time and call counts for all members.
+All calls into the cycle are made to share the total 
+time of the cycle, and all descendants of the cycle
+propagate time into the cycle as a whole.
+Calls among the members of the cycle 
+do not propagate any time,
+though they are listed in the call graph profile.
+.pp
+Figure 2 shows a modified version of the call graph of Figure 1,
+in which the nodes labelled 3 and 7 in Figure 1 are mutually
+recursive.
+The topologically sorted graph after the cycle is collapsed is
+given in Figure 3.
+.(z
+.so postp2.pic
+.ce 2
+Cycle to be collapsed.
+Figure 2.
+.ce 0
+.)z
+.(z
+.so postp3.pic
+.ce 2
+Topological numbering after cycle collapsing.
+Figure 3.
+.ce 0
+.)z
+.pp
+Since the technique described above only collects the
+dynamic call graph,
+and the program typically does not call every routine
+on each execution,
+different executions can introduce different cycles in the
+dynamic call graph.
+Since cycles often have a significant effect on time propagation,
+it is desirable to incorporate the static call graph so that cycles
+will have the same members regardless of how the program runs.
+.pp
+The static call graph can be constructed from the source text
+of the program.
+However, discovering the static call graph from the source text
+would require two moderately difficult steps:
+finding the source text for the program
+(which may not be available),
+and scanning and parsing that text,
+which may be in any one of several languages.
+.pp
+In our programming system,
+the static calling information is also contained in the 
+executable version of the program,
+which we already have available,
+and which is in language-independent form.
+One can examine the instructions
+in the object program,
+looking for calls to routines, and note which
+routines can be called.
+This technique allows us to add arcs to those already in the
+dynamic call graph.
+If a statically discovered arc already exists in the dynamic call
+graph, no action is required.
+Statically discovered arcs that do not exist in the dynamic call
+graph are added to the graph with a traversal count of zero.
+Thus they are never responsible for any time propagation.
+However, they may affect the structure of the graph.
+Since they may complete strongly connected components,
+the static call graph construction is
+done before topological ordering.
diff --git a/share/doc/psd/18.gprof/postp1.pic b/share/doc/psd/18.gprof/postp1.pic
new file mode 100644
index 0000000..1446092
--- /dev/null
+++ b/share/doc/psd/18.gprof/postp1.pic
@@ -0,0 +1,54 @@
+.\" Copyright (c) 1986, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)postp1.pic	8.1 (Berkeley) 6/8/93
+.\"
+.PS
+circle diam .3i "8"
+circle diam .3i "9" at 1st circle + (2i,0i)
+circle diam .3i "3" at 1st circle + (0.5i,-0.5i)
+circle diam .3i "7" at 2nd circle - (0.5i, 0.5i)
+circle diam .3i "2" at 1st circle - (0i,1i)
+circle diam .3i "5" at 5th circle + (1i,0i)
+circle diam .3i "6" at 2nd circle - (0i,1i)
+circle diam .3i "1" at 3rd circle - (0i,1i)
+circle diam .3i "4" at 4th circle - (0i,1i)
+arrow from 1st circle to 3rd circle chop .15i chop .15i
+arrow from 1st circle to 4th circle chop .15i chop .15i
+arrow from 2nd circle to 4th circle chop .15i chop .15i
+arrow from 3rd circle to 5th circle chop .15i chop .15i
+arrow from 4th circle to 5th circle chop .15i chop .15i
+arrow from 4th circle to 6th circle chop .15i chop .15i
+arrow from 4th circle to 7th circle chop .15i chop .15i
+arrow from 5th circle to 8th circle chop .15i chop .15i
+arrow from 6th circle to 8th circle chop .15i chop .15i
+arrow from 6th circle to 9th circle chop .15i chop .15i
+.PE
diff --git a/share/doc/psd/18.gprof/postp2.pic b/share/doc/psd/18.gprof/postp2.pic
new file mode 100644
index 0000000..3b31736
--- /dev/null
+++ b/share/doc/psd/18.gprof/postp2.pic
@@ -0,0 +1,56 @@
+.\" Copyright (c) 1986, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)postp2.pic	8.1 (Berkeley) 6/8/93
+.\"
+.PS
+circle diam .3i "\(ci"
+circle diam .3i "\(ci" at 1st circle + (2i,0i)
+circle diam .3i "\(bu" at 1st circle + (0.5i,-0.5i)
+circle diam .3i "\(bu" at 2nd circle - (0.5i, 0.5i)
+circle diam .3i "\(ci" at 1st circle - (0i,1i)
+circle diam .3i "\(ci" at 5th circle + (1i,0i)
+circle diam .3i "\(ci" at 2nd circle - (0i,1i)
+circle diam .3i "\(ci" at 3rd circle - (0i,1i)
+circle diam .3i "\(ci" at 4th circle - (0i,1i)
+arrow from 1st circle to 3rd circle chop .15i chop .15i
+arrow from 1st circle to 4th circle chop .15i chop .15i
+arrow from 2nd circle to 4th circle chop .15i chop .15i
+spline -> from 3rd circle right .5i up .075i then right .5i down .075i  chop .15i chop .15i
+spline -> from 4th circle left .5i down .075i then left .5i up .075i chop .15i chop .15i
+arrow from 3rd circle to 5th circle chop .15i chop .15i
+arrow from 4th circle to 5th circle chop .15i chop .15i
+arrow from 4th circle to 6th circle chop .15i chop .15i
+arrow from 4th circle to 7th circle chop .15i chop .15i
+arrow from 5th circle to 8th circle chop .15i chop .15i
+arrow from 6th circle to 8th circle chop .15i chop .15i
+arrow from 6th circle to 9th circle chop .15i chop .15i
+.PE
diff --git a/share/doc/psd/18.gprof/postp3.pic b/share/doc/psd/18.gprof/postp3.pic
new file mode 100644
index 0000000..65eb2a7
--- /dev/null
+++ b/share/doc/psd/18.gprof/postp3.pic
@@ -0,0 +1,51 @@
+.\" Copyright (c) 1986, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)postp3.pic	8.1 (Berkeley) 6/8/93
+.\"
+.PS
+circle diam .3i "7"
+circle diam .3i "8" at 1st circle + (2i,0i)
+EL: ellipse wid 1i ht .3i "\fB6\fR\h'.7i'\fB6\fR" at 1st circle + (1i,-0.5i)
+circle diam .3i "2" at 1st circle - (0i,1i)
+circle diam .3i "4" at 3th circle + (1i,0i)
+circle diam .3i "5" at 2nd circle - (0i,1i)
+circle diam .3i "1" at 3rd circle + (0.5i,-0.5i)
+circle diam .3i "3" at 5th circle - (0.5i,0.5i)
+arrow from 1st circle to EL.nw chop .15i chop 0i
+arrow from 2nd circle to EL.ne chop .15i chop 0i
+arrow from EL.sw to 3rd circle chop 0i chop .15i
+arrow from EL.s to 4th circle chop 0i chop .15i
+arrow from EL.se to 5th circle chop 0i chop .15i
+arrow from 3rd circle to 6th circle chop .15i chop .15i
+arrow from 4th circle to 6th circle chop .15i chop .15i
+arrow from 4th circle to 7th circle chop .15i chop .15i
+.PE
diff --git a/share/doc/psd/18.gprof/pres1.pic b/share/doc/psd/18.gprof/pres1.pic
new file mode 100644
index 0000000..0c311a1
--- /dev/null
+++ b/share/doc/psd/18.gprof/pres1.pic
@@ -0,0 +1,56 @@
+.\" Copyright (c) 1986, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)pres1.pic	8.1 (Berkeley) 6/8/93
+.\"
+.PS
+ellipse ht .3i wid .75i "\s-1CALLER1\s+1"
+ellipse ht .3i wid .75i "\s-1CALLER2\s+1" at 1st ellipse + (2i,0i)
+ellipse ht .3i wid .8i "\s-1EXAMPLE\s+1" at 1st ellipse + (1i,-.5i)
+ellipse ht .3i wid .5i "\s-1SUB1\s+1" at 1st ellipse - (0i,1i)
+ellipse ht .3i wid .5i "\s-1SUB2\s+1" at 3rd ellipse - (0i,.5i)
+ellipse ht .3i wid .5i "\s-1SUB3\s+1" at 2nd ellipse - (0i,1i)
+line <- from 1st ellipse up .5i left .5i chop .1875i
+line <- from 1st ellipse up .5i right .5i chop .1875i
+line <- from 2nd ellipse up .5i left .5i chop .1875i
+line <- from 2nd ellipse up .5i right .5i chop .1875i
+arrow from 1st ellipse to 3rd ellipse chop
+arrow from 2nd ellipse to 3rd ellipse chop
+arrow from 3rd ellipse to 4th ellipse chop
+arrow from 3rd ellipse to 5th ellipse chop .15i chop .15i
+arrow from 3rd ellipse to 6th ellipse chop
+arrow from 4th ellipse down .5i left .5i chop .1875i
+arrow from 4th ellipse down .5i right .5i chop .1875i
+arrow from 5th ellipse down .5i left .5i chop .1875i
+arrow from 5th ellipse down .5i right .5i chop .1875i
+arrow from 6th ellipse down .5i left .5i chop .1875i
+arrow from 6th ellipse down .5i right .5i chop .1875i
+.PE
diff --git a/share/doc/psd/18.gprof/pres2.pic b/share/doc/psd/18.gprof/pres2.pic
new file mode 100644
index 0000000..c3a4ea0
--- /dev/null
+++ b/share/doc/psd/18.gprof/pres2.pic
@@ -0,0 +1,52 @@
+.\" Copyright (c) 1986, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)pres2.pic	8.1 (Berkeley) 6/8/93
+.\"
+.PS
+ellipse ht .3i wid .6i "\s-1CALC1\s+1"
+ellipse ht .3i wid .6i "\s-1CALC2\s+1" at 1st ellipse + (.75i,0i)
+ellipse ht .3i wid .6i "\s-1CALC3\s+1" at 1st ellipse + (1.5i,0i)
+ellipse ht .3i wid .8i "\s-1FORMAT1\s+1" at 1st ellipse - (0i,.5i)
+ellipse ht .3i wid .8i "\s-1FORMAT2\s+1" at 3rd ellipse - (0i,.5i)
+ellipse ht .3i wid .75i "\s-1\"WRITE\"\s+1" at 5th ellipse - (.75i,.5i)
+line <- from 1st ellipse up .5i left .4i chop .1825i
+line <- from 1st ellipse up .5i right .4i chop .1825i
+line <- from 2nd ellipse up .5i left .4i chop .1825i
+line <- from 2nd ellipse up .5i right .4i chop .1825i
+line <- from 3rd ellipse up .5i left .4i chop .1825i
+line <- from 3rd ellipse up .5i right .4i chop .1825i
+arrow from 1st ellipse to 4th ellipse chop .15i
+arrow from 2nd ellipse to 5th ellipse chop 
+arrow from 3rd ellipse to 5th ellipse chop .15i
+arrow from 4th ellipse to 6th ellipse chop
+arrow from 5th ellipse to 6th ellipse chop
+.PE
diff --git a/share/doc/psd/18.gprof/present.me b/share/doc/psd/18.gprof/present.me
new file mode 100644
index 0000000..1dd7f62
--- /dev/null
+++ b/share/doc/psd/18.gprof/present.me
@@ -0,0 +1,306 @@
+.\" Copyright (c) 1982, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)present.me	8.1 (Berkeley) 6/8/93
+.\"
+.sh 1 "Data Presentation"
+.pp
+The data is presented to the user in two different formats.
+The first presentation simply lists the routines
+without regard to the amount of time their descendants use.
+The second presentation incorporates the call graph of the
+program.
+.sh 2 "The Flat Profile
+.pp
+The flat profile consists of a list of all the routines 
+that are called during execution of the program,
+with the count of the number of times they are called
+and the number of seconds of execution time for which they
+are themselves accountable.
+The routines are listed in decreasing order of execution time.
+A list of the routines that are never called during execution of
+the program is also available
+to verify that nothing important is omitted by
+this execution.
+The flat profile gives a quick overview of the routines that are used,
+and shows the routines that are themselves responsible
+for large fractions of the execution time.
+In practice,
+this profile usually shows that no single function
+is overwhelmingly responsible for 
+the total time of the program.
+Notice that for this profile,
+the individual times sum to the total execution time.
+.sh 2 "The Call Graph Profile"
+.sz 10
+.(z
+.TS
+box center;
+c c c c c l l
+c c c c c l l
+c c c c c l l
+l n n n c l l.
+				called/total	\ \ parents
+index	%time	self	descendants	called+self	name	index
+				called/total	\ \ children
+_
+		0.20	1.20	4/10	\ \ \s-1CALLER1\s+1	[7]
+		0.30	1.80	6/10	\ \ \s-1CALLER2\s+1	[1]
+[2]	41.5	0.50	3.00	10+4	\s-1EXAMPLE\s+1	[2]
+		1.50	1.00	20/40	\ \ \s-1SUB1\s+1 <cycle1>	[4]
+		0.00	0.50	1/5	\ \ \s-1SUB2\s+1 	[9]
+		0.00	0.00	0/5	\ \ \s-1SUB3\s+1 	[11]
+.TE
+.ce 2
+Profile entry for \s-1EXAMPLE\s+1.
+Figure 4.
+.)z
+.pp
+Ideally, we would like to print the call graph of the program,
+but we are limited by the two-dimensional nature of our output
+devices.
+We cannot assume that a call graph is planar,
+and even if it is, that we can print a planar version of it.
+Instead, we choose to list each routine,
+together with information about
+the routines that are its direct parents and children.
+This listing presents a window into the call graph.
+Based on our experience,
+both parent information and child information
+is important,
+and should be available without searching
+through the output.
+.pp
+The major entries of the call graph profile are the entries from the
+flat profile, augmented by the time propagated to each 
+routine from its descendants.
+This profile is sorted by the sum of the time for the routine
+itself plus the time inherited from its descendants.
+The profile shows which of the higher level routines 
+spend large portions of the total execution time 
+in the routines that they call.
+For each routine, we show the amount of time passed by each child
+to the routine, which includes time for the child itself
+and for the descendants of the child
+(and thus the descendants of the routine).
+We also show the percentage these times represent of the total time
+accounted to the child.
+Similarly, the parents of each routine are listed, 
+along with time,
+and percentage of total routine time,
+propagated to each one.
+.pp
+Cycles are handled as single entities.
+The cycle as a whole is shown as though it were a single routine,
+except that members of the cycle are listed in place of the children.
+Although the number of calls of each member
+from within the cycle are shown,
+they do not affect time propagation.
+When a child is a member of a cycle,
+the time shown is the appropriate fraction of the time
+for the whole cycle.
+Self-recursive routines have their calls broken
+down into calls from the outside and self-recursive calls.
+Only the outside calls affect the propagation of time.
+.pp
+The following example is a typical fragment of a call graph.
+.(b
+.so pres1.pic
+.)b
+The entry in the call graph profile listing for this example is
+shown in Figure 4.
+.pp
+The entry is for routine \s-1EXAMPLE\s+1, which has
+the Caller routines as its parents,
+and the Sub routines as its children.
+The reader should keep in mind that all information
+is given \fIwith respect to \s-1EXAMPLE\s+1\fP.
+The index in the first column shows that \s-1EXAMPLE\s+1
+is the second entry in the profile listing.
+The \s-1EXAMPLE\s+1 routine is called ten times, four times by \s-1CALLER1\s+1,
+and six times by \s-1CALLER2\s+1.
+Consequently 40% of \s-1EXAMPLE\s+1's time is propagated to \s-1CALLER1\s+1,
+and 60% of \s-1EXAMPLE\s+1's time is propagated to \s-1CALLER2\s+1.
+The self and descendant fields of the parents
+show the amount of self and descendant time \s-1EXAMPLE\s+1
+propagates to them (but not the time used by
+the parents directly).
+Note that \s-1EXAMPLE\s+1 calls itself recursively four times.
+The routine \s-1EXAMPLE\s+1 calls routine \s-1SUB1\s+1 twenty times, \s-1SUB2\s+1 once,
+and never calls \s-1SUB3\s+1.
+Since \s-1SUB2\s+1 is called a total of five times,
+20% of its self and descendant time is propagated to \s-1EXAMPLE\s+1's
+descendant time field.
+Because \s-1SUB1\s+1 is a member of \fIcycle 1\fR,
+the self and descendant times
+and call count fraction
+are those for the cycle as a whole.
+Since cycle 1 is called a total of forty times
+(not counting calls among members of the cycle),
+it propagates 50% of the cycle's self and descendant
+time to \s-1EXAMPLE\s+1's descendant time field.
+Finally each name is followed by an index that shows
+where on the listing to find the entry for that routine.
+.sh 1 "Using the Profiles"
+.pp
+The profiler is a useful tool for improving
+a set of routines that implement an abstraction.
+It can be helpful in identifying poorly coded routines,
+and in evaluating the new algorithms and code that replace them.
+Taking full advantage of the profiler 
+requires a careful examination of the call graph profile,
+and a thorough knowledge of the abstractions underlying
+the program.
+.pp
+The easiest optimization that can be performed
+is a small change
+to a control construct or data structure that improves the
+running time of the program.
+An obvious starting point
+is a routine that is called many times.
+For example, suppose an output 
+routine is the only parent
+of a routine that formats the data.
+If this format routine is expanded inline in the
+output routine, the overhead of a function call and
+return can be saved for each datum that needs to be formatted.
+.pp
+The drawback to inline expansion is that the data abstractions
+in the program may become less parameterized,
+hence less clearly defined.
+The profiling will also become less useful since the loss of 
+routines will make its output more granular.
+For example,
+if the symbol table functions ``lookup'', ``insert'', and ``delete''
+are all merged into a single parameterized routine,
+it will be impossible to determine the costs
+of any one of these individual functions from the profile.
+.pp
+Further potential for optimization lies in routines that
+implement data abstractions whose total execution
+time is long.
+For example, a lookup routine might be called only a few
+times, but use an inefficient linear search algorithm,
+that might be replaced with a binary search.
+Alternately, the discovery that a rehashing function is being
+called excessively, can lead to a different
+hash function or a larger hash table.
+If the data abstraction function cannot easily be speeded up,
+it may be advantageous to cache its results,
+and eliminate the need to rerun
+it for identical inputs.
+These and other ideas for program improvement are discussed in
+[Bentley81].
+.pp
+This tool is best used in an iterative approach:
+profiling the program,
+eliminating one bottleneck,
+then finding some other part of the program
+that begins to dominate execution time.
+For instance, we have used \fBgprof\fR on itself;
+eliminating, rewriting, and inline expanding routines,
+until reading
+data files (hardly a target for optimization!)
+represents the dominating factor in its execution time.
+.pp
+Certain types of programs are not easily analyzed by \fBgprof\fR.
+They are typified by programs that exhibit a large degree of 
+recursion, such as recursive descent compilers.
+The problem is that most of the major routines are grouped
+into a single monolithic cycle.
+As in the symbol table abstraction that is placed
+in one routine,
+it is impossible to distinguish which members of the cycle are
+responsible for the execution time.
+Unfortunately there are no easy modifications to these programs that
+make them amenable to analysis.
+.pp
+A completely different use of the profiler is to analyze the control
+flow of an unfamiliar program.
+If you receive a program from another user that you need to modify
+in some small way,
+it is often unclear where the changes need to be made.
+By running the program on an example and then using \fBgprof\fR,
+you can get a view of the structure of the program.
+.pp
+Consider an example in which you need to change the output format
+of the program.
+For purposes of this example suppose that the call graph
+of the output portion of the program has the following structure:
+.(b
+.so pres2.pic
+.)b
+Initially you look through the \fBgprof\fR
+output for the system call ``\s-1WRITE\s+1''.
+The format routine you will need to change is probably
+among the parents of the ``\s-1WRITE\s+1'' procedure.
+The next step is to look at the profile entry for each
+of parents of ``\s-1WRITE\s+1'',
+in this example either ``\s-1FORMAT1\s+1'' or ``\s-1FORMAT2\s+1'',
+to determine which one to change.
+Each format routine will have one or more parents,
+in this example ``\s-1CALC1\s+1'', ``\s-1CALC2\s+1'', and ``\s-1CALC3\s+1''.
+By inspecting the source code for each of these routines
+you can determine which format routine generates the output that
+you wish to modify.
+Since the \fBgprof\fR entry shows all the
+potential calls to the format routine you intend to change,
+you can determine if your modifications will affect output that
+should be left alone.
+If you desire to change the output of ``\s-1CALC2\s+1'', but not ``\s-1CALC3\s+1'',
+then formatting routine ``\s-1FORMAT2\s+1'' needs to be split
+into two separate routines,
+one of which implements the new format.
+You can then retarget just the call by ``\s-1CALC2\s+1''
+that needs the new format.
+It should be noted that the static call information is particularly
+useful here since the test case you run probably will not
+exercise the entire program.
+.sh 1 "Conclusions"
+.pp
+We have created a profiler that aids in the evaluation
+of modular programs.
+For each routine in the program,
+the profile shows the extent to which that routine
+helps support various abstractions,
+and how that routine uses other abstractions.
+The profile accurately assesses the cost of routines
+at all levels of the program decomposition.
+The profiler is easily used,
+and can be compiled into the program without any prior planning by
+the programmer.
+It adds only five to thirty percent execution overhead to the program
+being profiled,
+produces no additional output until after the program finishes,
+and allows the program to be measured in its actual environment.
+Finally, the profiler runs on a time-sharing system 
+using only the normal services provided by the operating system
+and compilers.
diff --git a/share/doc/psd/18.gprof/profiling.me b/share/doc/psd/18.gprof/profiling.me
new file mode 100644
index 0000000..227aedf
--- /dev/null
+++ b/share/doc/psd/18.gprof/profiling.me
@@ -0,0 +1,115 @@
+.\" Copyright (c) 1982, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)profiling.me	8.1 (Berkeley) 6/8/93
+.\"
+.sh 1 "Types of Profiling"
+.pp
+There are several different uses for program profiles,
+and each may require different information from the profiles,
+or different presentation of the information.
+We distinguish two broad categories of profiles:
+those that present counts of statement or routine invocations,
+and those that display timing information about statements
+or routines.
+Counts are typically presented in tabular form,
+often in parallel with a listing of the source code.
+Timing information could be similarly presented;
+but more than one measure of time might be associated with each
+statement or routine.
+For example,
+in the framework used by \fBgprof\fP
+each profiled segment would display two times:
+one for the time used by the segment itself, and another for the
+time inherited from code segments it invokes.
+.pp
+Execution counts are used in many different contexts.
+The exact number of times a routine or statement is activated
+can be used to determine if an algorithm is performing as 
+expected.
+Cursory inspection of such counters may show algorithms whose
+complexity is unsuited to the task at hand.
+Careful interpretation of counters can often suggest
+improvements to acceptable algorithms.
+Precise examination can uncover subtle errors in an
+algorithm.
+At this level, profiling counters are similar to
+debugging statements whose purpose is to show the number of times
+a piece of code is executed.
+Another view of such counters is as boolean values.
+One may be interested that a portion of code has executed at
+all, for exhaustive testing, or to check that one implementation
+of an abstraction completely replaces a previous one.
+.pp
+Execution counts are not necessarily proportional to the amount
+of time required to execute the routine or statement.
+Further, the execution time of a routine will not be the same for
+all calls on the routine.
+The criteria for establishing execution time
+must be decided.
+If a routine implements an abstraction by invoking other abstractions,
+the time spent in the routine will not accurately reflect the
+time required by the abstraction it implements.
+Similarly, if an abstraction is implemented by several
+routines the time required by the abstraction will be distributed
+across those routines.
+.pp
+Given the execution time of individual routines,
+\fBgprof\fP accounts to each routine the time spent
+for it by the routines it invokes.
+This accounting is done by assembling a \fIcall graph\fP with nodes that
+are the routines of the program and directed arcs that represent
+calls from call sites to routines.
+We distinguish among three different call graphs for a program.
+The \fIcomplete call graph\fP incorporates all routines and all
+potential arcs,
+including arcs that represent calls to functional parameters
+or functional variables.
+This graph contains the other two graphs as subgraphs.
+The \fIstatic call graph\fP includes all routines and all possible arcs
+that are not calls to functional parameters or variables.
+The \fIdynamic call graph\fP includes only those routines and
+arcs traversed by the profiled execution of the program.
+This graph need not include all routines, nor need it include all
+potential arcs between the routines it covers.
+It may, however, include arcs to functional parameters or
+variables that the static call graph may omit.
+The static call graph can be determined from the (static) program text.
+The dynamic call graph is determined only by profiling an
+execution of the program.
+The complete call graph for a monolithic program could be determined
+by data flow analysis techniques.
+The complete call graph for programs that change
+during execution, by modifying themselves or dynamically loading
+or overlaying code, may never be determinable.
+Both the static call graph and the dynamic call graph are used
+by \fBgprof\fP, but it does not search for the complete call
+graph.
diff --git a/share/doc/psd/18.gprof/refs.me b/share/doc/psd/18.gprof/refs.me
new file mode 100644
index 0000000..580d080
--- /dev/null
+++ b/share/doc/psd/18.gprof/refs.me
@@ -0,0 +1,63 @@
+.\" Copyright (c) 1982, 1993
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"	@(#)refs.me	8.1 (Berkeley) 6/8/93
+.\"
+.sh 1 "References"
+.ls 1
+.ip [Bentley81]
+Bentley, J. L.,
+``Writing Efficient Code'',
+Department of Computer Science,
+Carnegie-Mellon University,
+Pittsburgh, Pennsylvania,
+CMU-CS-81-116, 1981.
+.ip [Graham82]
+Graham, S. L., Henry, R. R., Schulman, R. A.,
+``An Experiment in Table Driven Code Generation'',
+SIGPLAN '82 Symposium on Compiler Construction,
+June, 1982.
+.ip [Joy79]
+Joy, W. N., Graham, S. L., Haley, C. B. ``Berkeley Pascal User's Manual'',
+Version 1.1, Computer Science Division
+University of California, Berkeley, CA. April 1979.
+.ip [Knuth71]
+Knuth, D. E. ``An empirical study of FORTRAN programs'',
+Software - Practice and Experience, 1, 105-133. 1971
+.ip [Satterthwaite72]
+Satterthwaite, E. ``Debugging Tools for High Level Languages'',
+Software - Practice and Experience, 2, 197-217, 1972
+.ip [Tarjan72]
+Tarjan, R. E., ``Depth first search and linear graph algorithm,''
+\fISIAM J. Computing\fP \fB1\fP:2, 146-160, 1972.
+.ip [Unix]
+Unix Programmer's Manual, ``\fBprof\fR command'', section 1,
+Bell Laboratories, Murray Hill, NJ. January 1979.
diff --git a/share/doc/psd/22.rpcgen/Makefile b/share/doc/psd/22.rpcgen/Makefile
index 4c38add..04d4e9e 100644
--- a/share/doc/psd/22.rpcgen/Makefile
+++ b/share/doc/psd/22.rpcgen/Makefile
@@ -4,6 +4,5 @@ VOLUME=		psd/22.rpcgen
 SRCS=		stubs rpcgen.ms
 MACROS=		-ms
 USE_TBL=
-SRCDIR=		${.CURDIR}/../../../../lib/libc/rpc/PSD.doc
 
 .include <bsd.doc.mk>
diff --git a/share/doc/psd/22.rpcgen/rpcgen.ms b/share/doc/psd/22.rpcgen/rpcgen.ms
new file mode 100644
index 0000000..e663e7f
--- /dev/null
+++ b/share/doc/psd/22.rpcgen/rpcgen.ms
@@ -0,0 +1,1301 @@
+.\"
+.\" Must use  --  tbl -- for this one
+.\"
+.\" @(#)rpcgen.ms	2.2 88/08/04 4.0 RPCSRC
+.\" $FreeBSD$
+.\"
+.de BT
+.if \\n%=1 .tl ''- % -''
+..
+.ND
+.\" prevent excess underlining in nroff
+.if n .fp 2 R
+.OH '\fBrpcgen\fP Programming Guide''Page %'
+.EH 'Page %''\fBrpcgen\fP Programming Guide'
+.if \n%=1 .bp
+.SH
+\&\fBrpcgen\fP Programming Guide
+.NH 0
+\&The \fBrpcgen\fP Protocol Compiler
+.IX rpcgen "" \fIrpcgen\fP "" PAGE MAJOR
+.LP
+.IX RPC "" "" \fIrpcgen\fP
+The details of programming applications to use Remote Procedure Calls 
+can be overwhelming.  Perhaps most daunting is the writing of the XDR 
+routines necessary to convert procedure arguments and results into 
+their network format and vice-versa.  
+.LP
+Fortunately, 
+.I rpcgen(1) 
+exists to help programmers write RPC applications simply and directly.
+.I rpcgen 
+does most of the dirty work, allowing programmers to debug 
+the  main  features of their application, instead of requiring them to
+spend most of their time debugging their network interface code.
+.LP
+.I rpcgen 
+is a  compiler.  It accepts a remote program interface definition written
+in a language, called RPC Language, which is similar to C.  It produces a C
+language output which includes stub versions of the client routines, a
+server skeleton, XDR filter routines for both parameters and results, and a
+header file that contains common definitions. The client stubs interface
+with the RPC library and effectively hide the network from their callers.
+The server stub similarly hides the network from the server procedures that
+are to be invoked by remote clients.
+.I rpcgen 's
+output files can be compiled and linked in the usual way.  The developer
+writes server procedures\(emin any language that observes Sun calling
+conventions\(emand links them with the server skeleton produced by
+.I rpcgen 
+to get an executable server program.  To use a remote program, a programmer
+writes an ordinary main program that makes local procedure calls to the 
+client stubs produced by
+.I rpcgen .
+Linking this program with 
+.I rpcgen 's
+stubs creates an executable program.  (At present the main program must be 
+written in C).
+.I rpcgen 
+options can be used to suppress stub generation and to specify the transport
+to be used by the server stub.
+.LP
+Like all compilers, 
+.I rpcgen 
+reduces development time
+that would otherwise be spent coding and debugging low-level routines.
+All compilers, including 
+.I rpcgen ,
+do this at a small cost in efficiency
+and flexibility.  However,   many compilers allow  escape  hatches for
+programmers to  mix low-level code with  high-level code. 
+.I rpcgen 
+is no exception.  In speed-critical applications, hand-written routines 
+can be linked with the 
+.I rpcgen 
+output without any difficulty.  Also, one may proceed by using
+.I rpcgen 
+output as a starting point, and then rewriting it as necessary.
+(If you need a discussion of RPC programming without
+.I rpcgen ,
+see the
+.I "Remote Procedure Call Programming Guide)\.
+.NH 1
+\&Converting Local Procedures into Remote Procedures
+.IX rpcgen "local procedures" \fIrpcgen\fP
+.IX rpcgen "remote procedures" \fIrpcgen\fP
+.LP
+Assume an application that runs on a single machine, one which we want 
+to convert to run over the network.  Here we will demonstrate such a 
+conversion by way of a simple example\(ema program that prints a 
+message to the console:
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * printmsg.c: print a message on the console
+ */
+.ft CW
+#include <stdio.h>
+
+main(argc, argv)
+	int argc;
+	char *argv[];
+{
+	char *message;
+
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s <message>\en", argv[0]);
+		exit(1);
+	}
+	message = argv[1];
+
+	if (!printmessage(message)) {
+		fprintf(stderr, "%s: couldn't print your message\en",
+			argv[0]);
+		exit(1);
+	} 
+	printf("Message Delivered!\en");
+	exit(0);
+}
+.ft I
+/*
+ * Print a message to the console.
+ * Return a boolean indicating whether the message was actually printed.
+ */
+.ft CW
+printmessage(msg)
+	char *msg;
+{
+	FILE *f;
+
+	f = fopen("/dev/console", "w");
+	if (f == NULL) {
+		return (0);
+	}
+	fprintf(f, "%s\en", msg);
+	fclose(f);
+	return(1);
+}
+.DE
+.LP
+And then, of course:
+.ie t .DS
+.el .DS L
+.ft CW
+example%  \fBcc printmsg.c -o printmsg\fP
+example%  \fBprintmsg "Hello, there."\fP
+Message delivered!
+example%
+.DE
+.LP
+If  
+.I printmessage() 
+was turned into  a remote procedure,
+then it could be  called from anywhere in   the network.  
+Ideally,  one would just  like to stick   a  keyword like  
+.I remote 
+in  front  of a
+procedure to turn it into a  remote procedure.  Unfortunately,
+we  have to live  within the  constraints of  the   C language, since 
+it existed   long before  RPC did.  But   even without language 
+support, it's not very difficult to make a procedure remote.
+.LP
+In  general, it's necessary to figure  out  what the types are for
+all procedure inputs and outputs.  In  this case,   we  have a 
+procedure
+.I printmessage() 
+which takes a  string as input, and returns  an integer
+as output.  Knowing  this, we can write a  protocol specification in RPC
+language that  describes the remote  version of 
+.I printmessage ().
+Here it is:
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * msg.x: Remote message printing protocol
+ */
+.ft CW
+
+program MESSAGEPROG {
+	version MESSAGEVERS {
+		int PRINTMESSAGE(string) = 1;
+	} = 1;
+} = 99;
+.DE
+.LP
+Remote procedures are part of remote programs, so we actually declared
+an  entire  remote program  here  which contains  the single procedure
+.I PRINTMESSAGE .
+This procedure was declared to be  in version  1 of the
+remote program.  No null procedure (procedure 0) is necessary because
+.I rpcgen 
+generates it automatically.
+.LP
+Notice that everything is declared with all capital  letters.  This is
+not required, but is a good convention to follow.
+.LP
+Notice also that the argument type is \*Qstring\*U and not \*Qchar *\*U.  This
+is because a \*Qchar *\*U in C is ambiguous.  Programmers usually intend it
+to mean  a null-terminated string   of characters, but  it  could also
+represent a pointer to a single character or a  pointer to an array of
+characters.  In  RPC language,  a  null-terminated  string is 
+unambiguously called a \*Qstring\*U.
+.LP
+There are  just two more things to  write.  First, there is the remote
+procedure itself.  Here's the definition of a remote procedure
+to implement the
+.I PRINTMESSAGE
+procedure we declared above:
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+ * msg_proc.c: implementation of the remote procedure "printmessage"
+ */
+.ft CW
+
+#include <stdio.h>
+#include <rpc/rpc.h>    /* \fIalways needed\fP  */
+#include "msg.h"        /* \fIneed this too: msg.h will be generated by rpcgen\fP */
+
+.ft I
+/*
+ * Remote verson of "printmessage"
+ */
+.ft CW
+int *
+printmessage_1(msg)
+	char **msg;
+{
+	static int result;  /* \fImust be static!\fP */
+	FILE *f;
+
+	f = fopen("/dev/console", "w");
+	if (f == NULL) {
+		result = 0;
+		return (&result);
+	}
+	fprintf(f, "%s\en", *msg);
+	fclose(f);
+	result = 1;
+	return (&result);
+}
+.vs
+.DE
+.LP
+Notice here that the declaration of the remote procedure
+.I printmessage_1() 
+differs from that of the local procedure
+.I printmessage() 
+in three ways:
+.IP  1.
+It takes a pointer to a string instead of a string itself.  This
+is true of all  remote procedures:  they always take pointers to  their
+arguments rather than the arguments themselves.
+.IP  2.
+It returns a pointer to an  integer instead of  an integer itself. This is
+also generally true of remote procedures: they always return a pointer
+to their results.
+.IP  3.
+It has an \*Q_1\*U appended to its name.  In general, all remote
+procedures called by 
+.I rpcgen 
+are named by  the following rule: the name in the program  definition  
+(here 
+.I PRINTMESSAGE )
+is converted   to all
+lower-case letters, an underbar (\*Q_\*U) is appended to it, and
+finally the version number (here 1) is appended.
+.LP
+The last thing to do is declare the main client program that will call
+the remote procedure. Here it is:
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * rprintmsg.c: remote version of "printmsg.c"
+ */
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>     /* \fIalways needed\fP  */
+#include "msg.h"         /* \fIneed this too: msg.h will be generated by rpcgen\fP */
+
+main(argc, argv)
+	int argc;
+	char *argv[];
+{
+	CLIENT *cl;
+	int *result;
+	char *server;
+	char *message;
+
+	if (argc < 3) {
+		fprintf(stderr, "usage: %s host message\en", argv[0]);
+		exit(1);
+	}
+
+.ft I
+	/*
+	 * Save values of command line arguments 
+	 */
+.ft CW
+	server = argv[1];
+	message = argv[2];
+
+.ft I
+	/*
+	 * Create client "handle" used for calling \fIMESSAGEPROG\fP on the
+	 * server designated on the command line. We tell the RPC package
+	 * to use the "tcp" protocol when contacting the server.
+	 */
+.ft CW
+	cl = clnt_create(server, MESSAGEPROG, MESSAGEVERS, "tcp");
+	if (cl == NULL) {
+.ft I
+		/*
+		 * Couldn't establish connection with server.
+		 * Print error message and die.
+		 */
+.ft CW
+		clnt_pcreateerror(server);
+		exit(1);
+	}
+
+.ft I
+	/*
+	 * Call the remote procedure "printmessage" on the server
+	 */
+.ft CW
+	result = printmessage_1(&message, cl);
+	if (result == NULL) {
+.ft I
+		/*
+		 * An error occurred while calling the server. 
+	 	 * Print error message and die.
+		 */
+.ft CW
+		clnt_perror(cl, server);
+		exit(1);
+	}
+
+.ft I
+	/*
+	 * Okay, we successfully called the remote procedure.
+	 */
+.ft CW
+	if (*result == 0) {
+.ft I
+		/*
+		 * Server was unable to print our message. 
+		 * Print error message and die.
+		 */
+.ft CW
+		fprintf(stderr, "%s: %s couldn't print your message\en", 
+			argv[0], server);	
+		exit(1);
+	} 
+
+.ft I
+	/*
+	 * The message got printed on the server's console
+	 */
+.ft CW
+	printf("Message delivered to %s!\en", server);
+}
+.DE
+There are two things to note here:
+.IP  1.
+.IX "client handle, used by rpcgen" "" "client handle, used by \fIrpcgen\fP"
+First a client \*Qhandle\*U is created using the RPC library routine
+.I clnt_create ().
+This client handle will be passed  to the stub routines
+which call the remote procedure.
+.IP  2.
+The remote procedure  
+.I printmessage_1() 
+is called exactly  the same way as it is  declared in 
+.I msg_proc.c 
+except for the inserted client handle as the first argument.
+.LP
+Here's how to put all of the pieces together:
+.ie t .DS
+.el .DS L
+.ft CW
+example%  \fBrpcgen msg.x\fP
+example%  \fBcc rprintmsg.c msg_clnt.c -o rprintmsg\fP
+example%  \fBcc msg_proc.c msg_svc.c -o msg_server\fP
+.DE
+Two programs were compiled here: the client program 
+.I rprintmsg 
+and the server  program 
+.I msg_server .
+Before doing this  though,  
+.I rpcgen 
+was used to fill in the missing pieces.  
+.LP
+Here is what 
+.I rpcgen 
+did with the input file 
+.I msg.x :
+.IP  1.
+It created a header file called 
+.I msg.h 
+that contained
+.I #define 's
+for
+.I MESSAGEPROG ,
+.I MESSAGEVERS 
+and    
+.I PRINTMESSAGE 
+for use in  the  other modules.
+.IP  2.
+It created client \*Qstub\*U routines in the
+.I msg_clnt.c 
+file.   In this case there is only one, the 
+.I printmessage_1() 
+that was referred to from the
+.I printmsg 
+client program.  The name  of the output file for
+client stub routines is always formed in this way:  if the name of the
+input file is  
+.I FOO.x ,
+the   client  stubs   output file is    called
+.I FOO_clnt.c .
+.IP  3.
+It created  the  server   program which calls   
+.I printmessage_1() 
+in
+.I msg_proc.c .
+This server program is named  
+.I msg_svc.c .
+The rule for naming the server output file is similar  to the 
+previous one:  for an input  file   called  
+.I FOO.x ,
+the   output   server   file is  named
+.I FOO_svc.c .
+.LP
+Now we're ready to have some fun.  First, copy the server to a
+remote machine and run it.  For this  example,  the
+machine is called \*Qmoon\*U.  Server processes are run in the
+background, because they never exit.
+.ie t .DS
+.el .DS L
+.ft CW
+moon% \fBmsg_server &\fP	       
+.DE
+Then on our local machine (\*Qsun\*U) we can print a message on \*Qmoon\*Us
+console.
+.ie t .DS
+.el .DS L
+.ft CW
+sun% \fBprintmsg moon "Hello, moon."\fP
+.DE
+The message will get printed to \*Qmoon\*Us console.  You can print a
+message on anybody's console (including your own) with this program if
+you are able to copy the server to their machine and run it.
+.NH 1
+\&Generating XDR Routines
+.IX RPC "generating XDR routines"
+.LP
+The previous example  only demonstrated  the  automatic generation of
+client  and server RPC  code. 
+.I rpcgen 
+may also  be used to generate XDR routines, that  is,  the routines
+necessary to  convert   local  data
+structures into network format and vice-versa.  This example presents
+a complete RPC service\(ema remote directory listing service, which uses
+.I rpcgen
+not  only  to generate stub routines, but also to  generate  the XDR
+routines.  Here is the protocol description file:
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * dir.x: Remote directory listing protocol
+ */
+.ft CW
+const MAXNAMELEN = 255;		/* \fImaximum length of a directory entry\fP */
+
+typedef string nametype<MAXNAMELEN>;	/* \fIa directory entry\fP */
+
+typedef struct namenode *namelist;		/* \fIa link in the listing\fP */
+
+.ft I
+/*
+ * A node in the directory listing
+ */
+.ft CW
+struct namenode {
+	nametype name;		/* \fIname of directory entry\fP */
+	namelist next;		/* \fInext entry\fP */
+};
+
+.ft I
+/*
+ * The result of a READDIR operation.
+ */
+.ft CW
+union readdir_res switch (int errno) {
+case 0:
+	namelist list;	/* \fIno error: return directory listing\fP */
+default:
+	void;		/* \fIerror occurred: nothing else to return\fP */
+};
+
+.ft I
+/*
+ * The directory program definition
+ */
+.ft CW
+program DIRPROG {
+	version DIRVERS {
+		readdir_res
+		READDIR(nametype) = 1;
+	} = 1;
+} = 76;
+.DE
+.SH
+Note:
+.I
+Types (like
+.I readdir_res 
+in the example above) can be defined using
+the \*Qstruct\*U, \*Qunion\*U and \*Qenum\*U keywords, but those keywords
+should not be used in subsequent declarations of variables of those types.
+For example, if you define a union \*Qfoo\*U, you should declare using
+only \*Qfoo\*U and not \*Qunion foo\*U.  In fact,
+.I rpcgen 
+compiles
+RPC unions into C structures and it is an error to declare them using the
+\*Qunion\*U keyword.
+.LP
+Running 
+.I rpcgen 
+on 
+.I dir.x 
+creates four output files.  Three are the same as before: header file,
+client stub routines and server skeleton.  The fourth are the XDR routines
+necessary for converting the data types we declared into XDR format and
+vice-versa.  These are output in the file
+.I dir_xdr.c .
+.LP
+Here is the implementation of the
+.I READDIR 
+procedure.
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+ * dir_proc.c: remote readdir implementation
+ */
+.ft CW
+#include <rpc/rpc.h>
+#include <sys/dir.h>
+#include "dir.h"
+
+extern int errno;
+extern char *malloc();
+extern char *strdup();
+
+readdir_res *
+readdir_1(dirname)
+	nametype *dirname;
+{
+	DIR *dirp;
+	struct direct *d;
+	namelist nl;
+	namelist *nlp;
+	static readdir_res res; /* \fImust be static\fP! */
+
+.ft I
+	/*
+	 * Open directory
+	 */
+.ft CW
+	dirp = opendir(*dirname);
+	if (dirp == NULL) {
+		res.errno = errno;
+		return (&res);
+	}
+
+.ft I
+	/*
+	 * Free previous result
+	 */
+.ft CW
+	xdr_free(xdr_readdir_res, &res);
+
+.ft I
+	/*
+	 * Collect directory entries.
+	 * Memory allocated here will be freed by \fIxdr_free\fP
+	 * next time \fIreaddir_1\fP is called
+	 */
+.ft CW
+	nlp = &res.readdir_res_u.list;
+	while (d = readdir(dirp)) {
+		nl = *nlp = (namenode *) malloc(sizeof(namenode));
+		nl->name = strdup(d->d_name);
+		nlp = &nl->next;
+	}
+	*nlp = NULL;
+
+.ft I
+	/*
+	 * Return the result
+	 */
+.ft CW
+	res.errno = 0;
+	closedir(dirp);
+	return (&res);
+}
+.vs
+.DE
+Finally, there is the client side program to call the server:
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * rls.c: Remote directory listing client
+ */
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>	/* \fIalways need this\fP */
+#include "dir.h"		/* \fIwill be generated by rpcgen\fP */
+
+extern int errno;
+
+main(argc, argv)
+	int argc;
+	char *argv[];
+{
+	CLIENT *cl;
+	char *server;
+	char *dir;
+	readdir_res *result;
+	namelist nl;
+
+
+	if (argc != 3) {
+		fprintf(stderr, "usage: %s host directory\en", 
+		  argv[0]);
+		exit(1);
+	}
+
+.ft I
+	/*
+	 * Remember what our command line arguments refer to
+	 */
+.ft CW
+	server = argv[1];
+	dir = argv[2];
+
+.ft I
+	/*
+	 * Create client "handle" used for calling \fIMESSAGEPROG\fP on the
+	 * server designated on the command line. We tell the RPC package
+	 * to use the "tcp" protocol when contacting the server.
+	 */
+.ft CW
+	cl = clnt_create(server, DIRPROG, DIRVERS, "tcp");
+	if (cl == NULL) {
+.ft I
+		/*
+		 * Couldn't establish connection with server.
+		 * Print error message and die.
+		 */
+.ft CW
+		clnt_pcreateerror(server);
+		exit(1);
+	}
+
+.ft I
+	/*
+	 * Call the remote procedure \fIreaddir\fP on the server
+	 */
+.ft CW
+	result = readdir_1(&dir, cl);
+	if (result == NULL) {
+.ft I
+		/*
+		 * An error occurred while calling the server. 
+	 	 * Print error message and die.
+		 */
+.ft CW
+		clnt_perror(cl, server);
+		exit(1);
+	}
+
+.ft I
+	/*
+	 * Okay, we successfully called the remote procedure.
+	 */
+.ft CW
+	if (result->errno != 0) {
+.ft I
+		/*
+		 * A remote system error occurred.
+		 * Print error message and die.
+		 */
+.ft CW
+		errno = result->errno;
+		perror(dir);
+		exit(1);
+	}
+
+.ft I
+	/*
+	 * Successfully got a directory listing.
+	 * Print it out.
+	 */
+.ft CW
+	for (nl = result->readdir_res_u.list; nl != NULL; 
+	  nl = nl->next) {
+		printf("%s\en", nl->name);
+	}
+	exit(0);
+}
+.DE
+Compile everything, and run.
+.DS
+.ft CW
+sun%  \fBrpcgen dir.x\fP
+sun%  \fBcc rls.c dir_clnt.c dir_xdr.c -o rls\fP
+sun%  \fBcc dir_svc.c dir_proc.c dir_xdr.c -o dir_svc\fP
+
+sun%  \fBdir_svc &\fP
+
+moon%  \fBrls sun /usr/pub\fP
+\&.
+\&..
+ascii
+eqnchar
+greek
+kbd
+marg8
+tabclr
+tabs
+tabs4
+moon%
+.DE
+.LP
+.IX "debugging with rpcgen" "" "debugging with \fIrpcgen\fP"
+A final note about 
+.I rpcgen :
+The client program and the server procedure can be tested together 
+as a single program by simply linking them with each other rather 
+than with the client and server stubs.  The procedure calls will be
+executed as ordinary local procedure calls and the program can be 
+debugged with a local debugger such as 
+.I dbx .
+When the program is working, the client program can be linked to 
+the client stub produced by 
+.I rpcgen 
+and the server procedures can be linked to the server stub produced
+by 
+.I rpcgen .
+.SH
+.I NOTE :
+\fIIf you do this, you may want to comment out calls to RPC library
+routines, and have client-side routines call server routines
+directly.\fP
+.LP
+.NH 1
+\&The C-Preprocessor
+.IX rpcgen "C-preprocessor" \fIrpcgen\fP
+.LP
+The C-preprocessor is  run on all input  files before they are
+compiled, so all the preprocessor directives are legal within a \*Q.x\*U
+file. Four symbols may be defined, depending upon which output file is
+getting generated. The symbols are:
+.TS
+box tab (&);
+lfI lfI
+lfL l .
+Symbol&Usage
+_
+RPC_HDR&for header-file output
+RPC_XDR&for XDR routine output
+RPC_SVC&for server-skeleton output
+RPC_CLNT&for client stub output
+.TE
+.LP
+Also, 
+.I rpcgen 
+does  a little preprocessing   of its own. Any  line that
+begins  with  a percent sign is passed  directly into the output file,
+without any interpretation of the line.  Here is a simple example that
+demonstrates the preprocessing features.
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * time.x: Remote time protocol
+ */
+.ft CW
+program TIMEPROG {
+        version TIMEVERS {
+                unsigned int TIMEGET(void) = 1;
+        } = 1;
+} = 44;
+
+#ifdef RPC_SVC
+%int *
+%timeget_1()
+%{
+%        static int thetime;
+%
+%        thetime = time(0);
+%        return (&thetime);
+%}
+#endif
+.DE
+The '%' feature is not generally recommended, as there is no guarantee
+that the compiler will stick the output where you intended.
+.NH 1
+\&\fBrpcgen\fP Programming Notes
+.IX rpcgen "other operations" \fIrpcgen\fP
+.sp 
+.NH 2
+\&Timeout Changes
+.IX rpcgen "timeout changes" \fIrpcgen\fP
+.LP
+RPC sets a default timeout of 25 seconds for RPC calls when
+.I clnt_create()
+is used.  This timeout may be changed using
+.I clnt_control()
+Here is a small code fragment to demonstrate use of
+.I clnt_control ():
+.ID
+struct timeval tv;
+CLIENT *cl;
+.sp .5
+cl = clnt_create("somehost", SOMEPROG, SOMEVERS, "tcp");
+if (cl == NULL) {
+	exit(1);
+}
+tv.tv_sec = 60;	/* \fIchange timeout to 1 minute\fP */
+tv.tv_usec = 0;
+clnt_control(cl, CLSET_TIMEOUT, &tv);	
+.DE
+.NH 2
+\&Handling Broadcast on the Server Side
+.IX "broadcast RPC"
+.IX rpcgen "broadcast RPC" \fIrpcgen\fP
+.LP
+When a procedure is known to be called via broadcast RPC,
+it is usually wise for the server to not reply unless it can provide
+some useful information to the client.  This prevents the network
+from getting flooded by useless replies.
+.LP
+To prevent the server from replying, a remote procedure can
+return NULL as its result, and the server code generated by
+.I rpcgen 
+will detect this and not send out a reply.
+.LP
+Here is an example of a procedure that replies only if it
+thinks it is an NFS server:
+.ID
+void *
+reply_if_nfsserver()
+{
+	char notnull;	/* \fIjust here so we can use its address\fP */
+.sp .5
+	if (access("/etc/exports", F_OK) < 0) {
+		return (NULL);	/* \fIprevent RPC from replying\fP */
+	}
+.ft I
+	/*
+	 * return non-null pointer so RPC will send out a reply
+	 */
+.ft L
+	return ((void *)&notnull);
+}
+.DE
+Note that if procedure returns type \*Qvoid *\*U, they must return a non-NULL
+pointer if they want RPC to reply for them.
+.NH 2
+\&Other Information Passed to Server Procedures
+.LP
+Server procedures will often want to know more about an RPC call
+than just its arguments.  For example, getting authentication information
+is important to procedures that want to implement some level of security.
+This extra information is actually supplied to the server procedure as a
+second argument.  Here is an example to demonstrate its use.  What we've
+done here is rewrite the previous
+.I printmessage_1() 
+procedure to only allow root users to print a message to the console.
+.ID
+int *
+printmessage_1(msg, rq)
+	char **msg;
+	struct svc_req	*rq;
+{
+	static in result;	/* \fIMust be static\fP */
+	FILE *f;
+	struct suthunix_parms *aup;
+.sp .5
+	aup = (struct authunix_parms *)rq->rq_clntcred;
+	if (aup->aup_uid != 0) {
+		result = 0;
+		return (&result);
+	}
+.sp
+.ft I
+	/*
+	 * Same code as before.
+	 */
+.ft L
+}
+.DE
+.NH 1
+\&RPC Language
+.IX RPCL
+.IX rpcgen "RPC Language" \fIrpcgen\fP
+.LP
+RPC language is an extension of XDR  language.   The sole extension is
+the addition of the
+.I program 
+type.  For a complete description of the XDR language syntax, see the
+.I "External Data Representation Standard: Protocol Specification"
+chapter.  For a description of the RPC extensions to the XDR language,
+see the
+.I "Remote Procedure Calls: Protocol Specification"
+chapter.
+.LP
+However, XDR language is so close to C that if you know C, you know most
+of it already.  We describe here  the syntax of the RPC language,
+showing a  few examples along the way.   We also show how  the various
+RPC and XDR type definitions get  compiled into C  type definitions in
+the output header file.
+.KS
+.NH 2
+Definitions
+\&
+.IX rpcgen definitions \fIrpcgen\fP
+.LP
+An RPC language file consists of a series of definitions.
+.DS L
+.ft CW
+    definition-list:
+        definition ";"
+        definition ";" definition-list
+.DE
+.KE
+It recognizes five types of definitions. 
+.DS L
+.ft CW
+    definition:
+        enum-definition
+        struct-definition
+        union-definition
+        typedef-definition
+        const-definition
+        program-definition
+.DE
+.NH 2
+Structures
+\&
+.IX rpcgen structures \fIrpcgen\fP
+.LP
+An XDR struct  is declared almost exactly like  its C counterpart.  It
+looks like the following:
+.DS L
+.ft CW
+    struct-definition:
+        "struct" struct-ident "{"
+            declaration-list
+        "}"
+
+    declaration-list:
+        declaration ";"
+        declaration ";" declaration-list
+.DE
+As an example, here is an XDR structure to a two-dimensional
+coordinate, and the C structure  that it  gets compiled into  in the
+output header file.
+.DS
+.ft CW
+   struct coord {             struct coord {
+        int x;       -->           int x;
+        int y;                     int y;
+   };                         };
+                              typedef struct coord coord;
+.DE
+The output is identical to the  input, except  for the added
+.I typedef
+at the end of the output.  This allows one to use \*Qcoord\*U instead of
+\*Qstruct coord\*U when declaring items.
+.NH 2
+Unions
+\&
+.IX rpcgen unions \fIrpcgen\fP
+.LP
+XDR unions are discriminated unions, and look quite different from C
+unions. They are more analogous to  Pascal variant records than they
+are to C unions.
+.DS L
+.ft CW
+    union-definition:
+        "union" union-ident "switch" "(" declaration ")" "{"
+            case-list
+        "}"
+
+    case-list:
+        "case" value ":" declaration ";"
+        "default" ":" declaration ";"
+        "case" value ":" declaration ";" case-list
+.DE
+Here is an example of a type that might be returned as the result of a
+\*Qread data\*U operation.  If there is no error, return a block of data.
+Otherwise, don't return anything.
+.DS L
+.ft CW
+    union read_result switch (int errno) {
+    case 0:
+        opaque data[1024];
+    default:
+        void;
+    };
+.DE
+It gets compiled into the following:
+.DS L
+.ft CW
+    struct read_result {
+        int errno;
+        union {
+            char data[1024];
+        } read_result_u;
+    };
+    typedef struct read_result read_result;
+.DE
+Notice that the union component of the  output struct  has the name as
+the type name, except for the trailing \*Q_u\*U.
+.NH 2
+Enumerations
+\&
+.IX rpcgen enumerations \fIrpcgen\fP
+.LP
+XDR enumerations have the same syntax as C enumerations.
+.DS L
+.ft CW
+    enum-definition:
+        "enum" enum-ident "{"
+            enum-value-list
+        "}"
+
+    enum-value-list:
+        enum-value
+        enum-value "," enum-value-list
+
+    enum-value:
+        enum-value-ident 
+        enum-value-ident "=" value
+.DE
+Here is a short example of  an XDR enum,  and the C enum that  it gets
+compiled into.
+.DS L
+.ft CW
+     enum colortype {      enum colortype {
+          RED = 0,              RED = 0,
+          GREEN = 1,   -->      GREEN = 1,
+          BLUE = 2              BLUE = 2,
+     };                    };
+                           typedef enum colortype colortype;
+.DE
+.NH 2
+Typedef
+\&
+.IX rpcgen typedef \fIrpcgen\fP
+.LP
+XDR typedefs have the same syntax as C typedefs.
+.DS L
+.ft CW
+    typedef-definition:
+        "typedef" declaration
+.DE
+Here  is an example  that defines a  
+.I fname_type 
+used  for declaring
+file name strings that have a maximum length of 255 characters.
+.DS L
+.ft CW
+typedef string fname_type<255>; --> typedef char *fname_type;
+.DE
+.NH 2
+Constants
+\&
+.IX rpcgen constants \fIrpcgen\fP
+.LP
+XDR constants  symbolic constants  that may be  used wherever  a
+integer constant is used, for example, in array size specifications.
+.DS L
+.ft CW
+    const-definition:
+        "const" const-ident "=" integer
+.DE
+For example, the following defines a constant
+.I DOZEN 
+equal to 12.
+.DS L
+.ft CW
+    const DOZEN = 12;  -->  #define DOZEN 12
+.DE
+.NH 2
+Programs
+\&
+.IX rpcgen programs \fIrpcgen\fP
+.LP
+RPC programs are declared using the following syntax:
+.DS L
+.ft CW
+    program-definition:
+        "program" program-ident "{" 
+            version-list
+        "}" "=" value 
+
+    version-list:
+        version ";"
+        version ";" version-list
+
+    version:
+        "version" version-ident "{"
+            procedure-list 
+        "}" "=" value
+
+    procedure-list:
+        procedure ";"
+        procedure ";" procedure-list
+
+    procedure:
+        type-ident procedure-ident "(" type-ident ")" "=" value
+.DE
+For example, here is the time protocol, revisited:
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * time.x: Get or set the time. Time is represented as number of seconds
+ * since 0:00, January 1, 1970.
+ */
+.ft CW
+program TIMEPROG {
+    version TIMEVERS {
+        unsigned int TIMEGET(void) = 1;
+        void TIMESET(unsigned) = 2;
+    } = 1;
+} = 44;        
+.DE
+This file compiles into #defines in the output header file:
+.ie t .DS
+.el .DS L
+.ft CW
+#define TIMEPROG 44
+#define TIMEVERS 1
+#define TIMEGET 1
+#define TIMESET 2
+.DE
+.NH 2
+Declarations
+\&
+.IX rpcgen declarations \fIrpcgen\fP
+.LP
+In XDR, there are only four kinds of declarations.  
+.DS L
+.ft CW
+    declaration:
+        simple-declaration
+        fixed-array-declaration
+        variable-array-declaration
+        pointer-declaration
+.DE
+\fB1) Simple declarations\fP are just like simple C declarations.
+.DS L
+.ft CW
+    simple-declaration:
+        type-ident variable-ident
+.DE
+Example:
+.DS L
+.ft CW
+    colortype color;    --> colortype color;
+.DE
+\fB2) Fixed-length Array Declarations\fP are just like C array declarations:
+.DS L
+.ft CW
+    fixed-array-declaration:
+        type-ident variable-ident "[" value "]"
+.DE
+Example:
+.DS L
+.ft CW
+    colortype palette[8];    --> colortype palette[8];
+.DE
+\fB3) Variable-Length Array Declarations\fP have no explicit syntax 
+in C, so XDR invents its own using angle-brackets.
+.DS L
+.ft CW
+variable-array-declaration:
+    type-ident variable-ident "<" value ">"
+    type-ident variable-ident "<" ">"
+.DE
+The maximum size is specified between the angle brackets. The size may
+be omitted, indicating that the array may be of any size.
+.DS L
+.ft CW
+    int heights<12>;    /* \fIat most 12 items\fP */
+    int widths<>;       /* \fIany number of items\fP */
+.DE
+Since  variable-length  arrays have no  explicit  syntax in  C,  these
+declarations are actually compiled into \*Qstruct\*Us.  For example, the
+\*Qheights\*U declaration gets compiled into the following struct:
+.DS L
+.ft CW
+    struct {
+        u_int heights_len;  /* \fI# of items in array\fP */
+        int *heights_val;   /* \fIpointer to array\fP */
+    } heights;
+.DE
+Note that the number of items in the array is stored in the \*Q_len\*U
+component and the pointer to the array is stored in the \*Q_val\*U
+component. The first part of each of these component's names is the
+same as the name of the declared XDR variable.
+.LP
+\fB4) Pointer Declarations\fP are made in 
+XDR  exactly as they  are  in C.  You  can't
+really send pointers over the network,  but  you  can use XDR pointers
+for sending recursive data types such as lists and trees.  The type is
+actually called \*Qoptional-data\*U, not \*Qpointer\*U, in XDR language.
+.DS L
+.ft CW
+    pointer-declaration:
+        type-ident "*" variable-ident
+.DE
+Example:
+.DS L
+.ft CW
+    listitem *next;  -->  listitem *next;
+.DE
+.NH 2
+\&Special Cases
+.IX rpcgen "special cases" \fIrpcgen\fP
+.LP
+There are a few exceptions to the rules described above.
+.LP
+.B Booleans:
+C has no built-in boolean type. However, the RPC library does  a
+boolean type   called 
+.I bool_t 
+that   is either  
+.I TRUE 
+or  
+.I FALSE .
+Things declared as  type 
+.I bool 
+in  XDR language  are  compiled  into
+.I bool_t 
+in the output header file.
+.LP
+Example:
+.DS L
+.ft CW
+    bool married;  -->  bool_t married;
+.DE
+.B Strings:
+C has  no built-in string  type, but  instead uses the null-terminated
+\*Qchar *\*U convention.  In XDR language, strings are declared using the
+\*Qstring\*U keyword, and compiled into \*Qchar *\*Us in the output header
+file. The  maximum size contained  in the angle brackets specifies the
+maximum number of characters allowed in the  strings (not counting the
+.I NULL 
+character). The maximum size may be left off, indicating a string
+of arbitrary length.
+.LP
+Examples:
+.DS L
+.ft CW
+    string name<32>;    -->  char *name;
+    string longname<>;  -->  char *longname;
+.DE
+.B "Opaque  Data:"
+Opaque data is used in RPC and XDR to describe untyped  data, that is,
+just  sequences of arbitrary  bytes.  It may be  declared  either as a
+fixed or variable length array.
+.DS L
+Examples:
+.ft CW
+    opaque diskblock[512];  -->  char diskblock[512];
+
+    opaque filedata<1024>;  -->  struct {
+                                    u_int filedata_len;
+                                    char *filedata_val;
+                                 } filedata;
+.DE
+.B Voids:
+In a void declaration, the variable is  not named.  The declaration is
+just \*Qvoid\*U and nothing else.  Void declarations can only occur in two
+places: union definitions and program definitions (as the  argument or
+result of a remote procedure).
diff --git a/share/doc/psd/22.rpcgen/stubs b/share/doc/psd/22.rpcgen/stubs
new file mode 100644
index 0000000..78b0a2c
--- /dev/null
+++ b/share/doc/psd/22.rpcgen/stubs
@@ -0,0 +1,3 @@
+.\" $FreeBSD$
+.\"
+.if t .ftr L CR
diff --git a/share/doc/psd/23.rpc/Makefile b/share/doc/psd/23.rpc/Makefile
index 77849b6..930c677 100644
--- a/share/doc/psd/23.rpc/Makefile
+++ b/share/doc/psd/23.rpc/Makefile
@@ -5,6 +5,5 @@ SRCS=		stubs rpc.prog.ms
 MACROS=		-ms
 USE_TBL=
 USE_PIC=
-SRCDIR=		${.CURDIR}/../../../../lib/libc/rpc/PSD.doc
 
 .include <bsd.doc.mk>
diff --git a/share/doc/psd/23.rpc/rpc.prog.ms b/share/doc/psd/23.rpc/rpc.prog.ms
new file mode 100644
index 0000000..8b79130
--- /dev/null
+++ b/share/doc/psd/23.rpc/rpc.prog.ms
@@ -0,0 +1,2686 @@
+.\"
+.\" Must use -- tbl and pic -- with this one
+.\"
+.\" @(#)rpc.prog.ms	2.3 88/08/11 4.0 RPCSRC
+.\" $FreeBSD$
+.\"
+.de BT
+.if \\n%=1 .tl ''- % -''
+..
+.nr OF 0
+.ND
+.\" prevent excess underlining in nroff
+.if n .fp 2 R
+.OH 'Remote Procedure Call Programming Guide''Page %'
+.EH 'Page %''Remote Procedure Call Programming Guide'
+.SH
+\&Remote Procedure Call Programming Guide
+.nr OF 1
+.IX "Network Programming" "" "" "" PAGE MAJOR
+.IX "RPC Programming Guide"
+.LP
+This document assumes a working knowledge of network theory.  It is
+intended for programmers who wish to write network applications using
+remote procedure calls (explained below), and who want to understand
+the RPC mechanisms usually hidden by the
+.I rpcgen(1)
+protocol compiler.
+.I rpcgen
+is described in detail in the previous chapter, the
+.I "\fBrpcgen\fP \fIProgramming Guide\fP".
+.SH
+Note:
+.I
+.IX rpcgen "" \fIrpcgen\fP
+Before attempting to write a network application, or to convert an
+existing non-network application to run over the network, you may want to
+understand the material in this chapter.  However, for most applications,
+you can circumvent the need to cope with the details presented here by using
+.I rpcgen .
+The
+.I "Generating XDR Routines"
+section of that chapter contains the complete source for a working RPC
+service\(ema remote directory listing service which uses
+.I rpcgen
+to generate XDR routines as well as client and server stubs.
+.LP
+.LP
+What are remote procedure calls?  Simply put, they are the high-level
+communications paradigm used in the operating system.
+RPC presumes the existence of
+low-level networking mechanisms (such as TCP/IP and UDP/IP), and upon them
+it implements a logical client to server communications system designed
+specifically for the support of network applications.  With RPC, the client
+makes a procedure call to send a data packet to the server.  When the
+packet arrives, the server calls a dispatch routine, performs whatever
+service is requested, sends back the reply, and the procedure call returns
+to the client.
+.NH 0
+\&Layers of RPC
+.IX "layers of RPC"
+.IX "RPC" "layers"
+.LP
+The RPC interface can be seen as being divided into three layers.\**
+.FS
+For a complete specification of the routines in the remote procedure
+call Library, see the
+.I rpc(3N)
+manual page.
+.FE
+.LP
+.I "The Highest Layer:"
+.IX RPC "The Highest Layer"
+The highest layer is totally transparent to the operating system,
+machine and network upon which is is run.  It's probably best to
+think of this level as a way of
+.I using
+RPC, rather than as
+a \fIpart of\fP RPC proper.  Programmers who write RPC routines
+should (almost) always make this layer available to others by way
+of a simple C front end that entirely hides the networking.
+.LP
+To illustrate, at this level a program can simply make a call to
+.I rnusers (),
+a C routine which returns the number of users on a remote machine.
+The user is not explicitly aware of using RPC \(em they simply
+call a procedure, just as they would call
+.I malloc() .
+.LP
+.I "The Middle Layer:"
+.IX RPC "The Middle Layer"
+The middle layer is really \*QRPC proper.\*U  Here, the user doesn't
+need to consider details about sockets, the UNIX system, or other low-level
+implementation mechanisms.  They simply make remote procedure calls
+to routines on other machines.  The selling point here is simplicity.
+It's this layer that allows RPC to pass the \*Qhello world\*U test \(em
+simple things should be simple.  The middle-layer routines are used
+for most applications.
+.LP
+RPC calls are made with the system routines
+.I registerrpc()
+.I callrpc()
+and
+.I svc_run ().
+The first two of these are the most fundamental:
+.I registerrpc()
+obtains a unique system-wide procedure-identification number, and
+.I callrpc()
+actually executes a remote procedure call.  At the middle level, a
+call to
+.I rnusers()
+is implemented by way of these two routines.
+.LP
+The middle layer is unfortunately rarely used in serious programming
+due to its inflexibility (simplicity).  It does not allow timeout
+specifications or the choice of transport.  It allows no UNIX
+process control or flexibility in case of errors.  It doesn't support
+multiple kinds of call authentication.  The programmer rarely needs
+all these kinds of control, but one or two of them is often necessary.
+.LP
+.I "The Lowest Layer:"
+.IX RPC "The Lowest Layer"
+The lowest layer does allow these details to be controlled by the
+programmer, and for that reason it is often necessary.  Programs
+written at this level are also most efficient, but this is rarely a
+real issue \(em since RPC clients and servers rarely generate
+heavy network loads.
+.LP
+Although this document only discusses the interface to C,
+remote procedure calls can be made from any language.
+Even though this document discusses RPC
+when it is used to communicate
+between processes on different machines,
+it works just as well for communication
+between different processes on the same machine.
+.br
+.KS
+.NH 2
+\&The RPC Paradigm
+.IX RPC paradigm
+.LP
+Here is a diagram of the RPC paradigm:
+.LP
+\fBFigure 1-1\fI Network Communication with the Remote Reocedure Call\fR
+.LP
+.PS
+L1: arrow down 1i "client " rjust "program " rjust
+L2: line right 1.5i "\fIcallrpc\fP" "function"
+move up 1.5i; line dotted down 6i; move up 4.5i
+arrow right 1i
+L3: arrow down 1i "invoke " rjust "service " rjust
+L4: arrow right 1.5i "call" "service"
+L5: arrow down 1i " service" ljust " executes" ljust
+L6: arrow left 1.5i "\fIreturn\fP" "answer"
+L7: arrow down 1i "request " rjust "completed " rjust
+L8: line left 1i
+arrow left 1.5i "\fIreturn\fP" "reply"
+L9: arrow down 1i "program " rjust "continues " rjust
+line dashed down from L2 to L9
+line dashed down from L4 to L7
+line dashed up 1i from L3 "service " rjust "daemon " rjust
+arrow dashed down 1i from L8
+move right 1i from L3
+box invis "Machine B"
+move left 1.2i from L2; move down
+box invis "Machine A"
+.PE
+.KE
+.KS
+.NH 1
+\&Higher Layers of RPC
+.NH 2
+\&Highest Layer
+.IX "highest layer of RPC"
+.IX RPC "highest layer"
+.LP
+Imagine you're writing a program that needs to know
+how many users are logged into a remote machine.
+You can do this by calling the RPC library routine
+.I rnusers()
+as illustrated below:
+.ie t .DS
+.el .DS L
+.ft CW
+#include <stdio.h>
+
+main(argc, argv)
+	int argc;
+	char **argv;
+{
+	int num;
+
+	if (argc != 2) {
+		fprintf(stderr, "usage: rnusers hostname\en");
+		exit(1);
+	}
+	if ((num = rnusers(argv[1])) < 0) {
+		fprintf(stderr, "error: rnusers\en");
+		exit(-1);
+	}
+	printf("%d users on %s\en", num, argv[1]);
+	exit(0);
+}
+.DE
+.KE
+RPC library routines such as
+.I rnusers()
+are in the RPC services library
+.I librpcsvc.a
+Thus, the program above should be compiled with
+.DS
+.ft CW
+% cc \fIprogram.c -lrpcsvc\fP
+.DE
+.I rnusers (),
+like the other RPC library routines, is documented in section 3R
+of the
+.I "System Interface Manual for the Sun Workstation" ,
+the same section which documents the standard Sun RPC services.
+.IX "RPC Services"
+See the
+.I intro(3R)
+manual page for an explanation of the documentation strategy
+for these services and their RPC protocols.
+.LP
+Here are some of the RPC service library routines available to the
+C programmer:
+.LP
+\fBTable 3-3\fI RPC Service Library Routines\fR
+.TS
+box tab (&) ;
+cfI cfI
+lfL l .
+Routine&Description
+_
+.sp .5
+rnusers&Return number of users on remote machine
+rusers&Return information about users on remote machine
+havedisk&Determine if remote machine has disk
+rstats&Get performance data from remote kernel
+rwall&Write to specified remote machines
+yppasswd&Update user password in Yellow Pages
+.TE
+.LP
+Other RPC services \(em for example
+.I ether()
+.I mount
+.I rquota()
+and
+.I spray
+\(em are not available to the C programmer as library routines.
+They do, however,
+have RPC program numbers so they can be invoked with
+.I callrpc()
+which will be discussed in the next section.  Most of them also
+have compilable
+.I rpcgen(1)
+protocol description files.  (The
+.I rpcgen
+protocol compiler radically simplifies the process of developing
+network applications.
+See the \fBrpcgen\fI Programming Guide\fR
+for detailed information about
+.I rpcgen
+and
+.I rpcgen
+protocol description files).
+.KS
+.NH 2
+\&Intermediate Layer
+.IX "intermediate layer of RPC"
+.IX "RPC" "intermediate layer"
+.LP
+The simplest interface, which explicitly makes RPC calls, uses the
+functions
+.I callrpc()
+and
+.I registerrpc()
+Using this method, the number of remote users can be gotten as follows:
+.ie t .DS
+.el .DS L
+#include <stdio.h>
+#include <rpc/rpc.h>
+#include <utmp.h>
+#include <rpcsvc/rusers.h>
+
+main(argc, argv)
+	int argc;
+	char **argv;
+{
+	unsigned long nusers;
+	int stat;
+
+	if (argc != 2) {
+		fprintf(stderr, "usage: nusers hostname\en");
+		exit(-1);
+	}
+	if (stat = callrpc(argv[1],
+	  RUSERSPROG, RUSERSVERS, RUSERSPROC_NUM,
+	  xdr_void, 0, xdr_u_long, &nusers) != 0) {
+		clnt_perrno(stat);
+		exit(1);
+	}
+	printf("%d users on %s\en", nusers, argv[1]);
+	exit(0);
+}
+.DE
+.KE
+Each RPC procedure is uniquely defined by a program number,
+version number, and procedure number.  The program number
+specifies a group of related remote procedures, each of
+which has a different procedure number.  Each program also
+has a version number, so when a minor change is made to a
+remote service (adding a new procedure, for example), a new
+program number doesn't have to be assigned.  When you want
+to call a procedure to find the number of remote users, you
+look up the appropriate program, version and procedure numbers
+in a manual, just as you look up the name of a memory allocator
+when you want to allocate memory.
+.LP
+The simplest way of making remote procedure calls is with the the RPC
+library routine
+.I callrpc()
+It has eight parameters.  The first is the name of the remote server
+machine.  The next three parameters are the program, version, and procedure
+numbers\(emtogether they identify the procedure to be called.
+The fifth and sixth parameters are an XDR filter and an argument to
+be encoded and passed to the remote procedure.
+The final two parameters are a filter for decoding the results
+returned by the remote procedure and a pointer to the place where
+the procedure's results are to be stored.  Multiple arguments and
+results are handled by embedding them in structures.  If
+.I callrpc()
+completes successfully, it returns zero; else it returns a nonzero
+value.  The return codes (of type
+.IX "enum clnt_stat (in RPC programming)" "" "\fIenum clnt_stat\fP (in RPC programming)"
+cast into an integer) are found in
+.I <rpc/clnt.h> .
+.LP
+Since data types may be represented differently on different machines,
+.I callrpc()
+needs both the type of the RPC argument, as well as
+a pointer to the argument itself (and similarly for the result).  For
+.I RUSERSPROC_NUM ,
+the return value is an
+.I "unsigned long"
+so
+.I callrpc()
+has
+.I xdr_u_long()
+as its first return parameter, which says
+that the result is of type
+.I "unsigned long"
+and
+.I &nusers
+as its second return parameter,
+which is a pointer to where the long result will be placed.  Since
+.I RUSERSPROC_NUM
+takes no argument, the argument parameter of
+.I callrpc()
+is
+.I xdr_void ().
+.LP
+After trying several times to deliver a message, if
+.I callrpc()
+gets no answer, it returns with an error code.
+The delivery mechanism is UDP,
+which stands for User Datagram Protocol.
+Methods for adjusting the number of retries
+or for using a different protocol require you to use the lower
+layer of the RPC library, discussed later in this document.
+The remote server procedure
+corresponding to the above might look like this:
+.ie t .DS
+.el .DS L
+.ft CW
+.ft CW
+char *
+nuser(indata)
+	char *indata;
+{
+	unsigned long nusers;
+
+.ft I
+	/*
+	 * Code here to compute the number of users
+	 * and place result in variable \fInusers\fP.
+	 */
+.ft CW
+	return((char *)&nusers);
+}
+.DE
+.LP
+It takes one argument, which is a pointer to the input
+of the remote procedure call (ignored in our example),
+and it returns a pointer to the result.
+In the current version of C,
+character pointers are the generic pointers,
+so both the input argument and the return value are cast to
+.I "char *" .
+.LP
+Normally, a server registers all of the RPC calls it plans
+to handle, and then goes into an infinite loop waiting to service requests.
+In this example, there is only a single procedure
+to register, so the main body of the server would look like this:
+.ie t .DS
+.el .DS L
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>
+#include <utmp.h>
+#include <rpcsvc/rusers.h>
+
+char *nuser();
+
+main()
+{
+	registerrpc(RUSERSPROG, RUSERSVERS, RUSERSPROC_NUM,
+		nuser, xdr_void, xdr_u_long);
+	svc_run();		/* \fINever returns\fP */
+	fprintf(stderr, "Error: svc_run returned!\en");
+	exit(1);
+}
+.DE
+.LP
+The
+.I registerrpc()
+routine registers a C procedure as corresponding to a
+given RPC procedure number.  The first three parameters,
+.I RUSERPROG ,
+.I RUSERSVERS ,
+and
+.I RUSERSPROC_NUM
+are the program, version, and procedure numbers
+of the remote procedure to be registered;
+.I nuser()
+is the name of the local procedure that implements the remote
+procedure; and
+.I xdr_void()
+and
+.I xdr_u_long()
+are the XDR filters for the remote procedure's arguments and
+results, respectively.  (Multiple arguments or multiple results
+are passed as structures).
+.LP
+Only the UDP transport mechanism can use
+.I registerrpc()
+thus, it is always safe in conjunction with calls generated by
+.I callrpc() .
+.SH
+.IX "UDP 8K warning"
+Warning: the UDP transport mechanism can only deal with
+arguments and results less than 8K bytes in length.
+.LP
+.LP
+After registering the local procedure, the server program's
+main procedure calls
+.I svc_run (),
+the RPC library's remote procedure dispatcher.  It is this
+function that calls the remote procedures in response to RPC
+call messages.  Note that the dispatcher takes care of decoding
+remote procedure arguments and encoding results, using the XDR
+filters specified when the remote procedure was registered.
+.NH 2
+\&Assigning Program Numbers
+.IX "program number assignment"
+.IX "assigning program numbers"
+.LP
+Program numbers are assigned in groups of
+.I 0x20000000
+according to the following chart:
+.DS
+.ft CW
+       0x0 - 0x1fffffff	\fRDefined by Sun\fP
+0x20000000 - 0x3fffffff	\fRDefined by user\fP
+0x40000000 - 0x5fffffff	\fRTransient\fP
+0x60000000 - 0x7fffffff	\fRReserved\fP
+0x80000000 - 0x9fffffff	\fRReserved\fP
+0xa0000000 - 0xbfffffff	\fRReserved\fP
+0xc0000000 - 0xdfffffff	\fRReserved\fP
+0xe0000000 - 0xffffffff	\fRReserved\fP
+.ft R
+.DE
+Sun Microsystems administers the first group of numbers, which
+should be identical for all Sun customers.  If a customer
+develops an application that might be of general interest, that
+application should be given an assigned number in the first
+range.  The second group of numbers is reserved for specific
+customer applications.  This range is intended primarily for
+debugging new programs.  The third group is reserved for
+applications that generate program numbers dynamically.  The
+final groups are reserved for future use, and should not be
+used.
+.LP
+To register a protocol specification, send a request by network
+mail to
+.I rpc@sun
+or write to:
+.DS
+RPC Administrator
+Sun Microsystems
+2550 Garcia Ave.
+Mountain View, CA 94043
+.DE
+Please include a compilable
+.I rpcgen
+\*Q.x\*U file describing your protocol.
+You will be given a unique program number in return.
+.IX RPC administration
+.IX administration "of RPC"
+.LP
+The RPC program numbers and protocol specifications
+of standard Sun RPC services can be
+found in the include files in
+.I "/usr/include/rpcsvc" .
+These services, however, constitute only a small subset
+of those which have been registered.  The complete list of
+registered programs, as of the time when this manual was
+printed, is:
+.LP
+\fBTable 3-2\fI RPC Registered Programs\fR
+.TS H
+box tab (&) ;
+lfBI lfBI lfBI
+lfL lfL lfI .
+RPC Number&Program&Description
+_
+.TH
+.sp .5
+100000&PMAPPROG&portmapper
+100001&RSTATPROG&remote stats
+100002&RUSERSPROG&remote users
+100003&NFSPROG&nfs
+100004&YPPROG&Yellow Pages
+100005&MOUNTPROG&mount daemon
+100006&DBXPROG&remote dbx
+100007&YPBINDPROG&yp binder
+100008&WALLPROG&shutdown msg
+100009&YPPASSWDPROG&yppasswd server
+100010&ETHERSTATPROG&ether stats
+100011&RQUOTAPROG&disk quotas
+100012&SPRAYPROG&spray packets
+100013&IBM3270PROG&3270 mapper
+100014&IBMRJEPROG&RJE mapper
+100015&SELNSVCPROG&selection service
+100016&RDATABASEPROG&remote database access
+100017&REXECPROG&remote execution
+100018&ALICEPROG&Alice Office Automation
+100019&SCHEDPROG&scheduling service
+100020&LOCKPROG&local lock manager
+100021&NETLOCKPROG&network lock manager
+100022&X25PROG&x.25 inr protocol
+100023&STATMON1PROG&status monitor 1
+100024&STATMON2PROG&status monitor 2
+100025&SELNLIBPROG&selection library
+100026&BOOTPARAMPROG&boot parameters service
+100027&MAZEPROG&mazewars game
+100028&YPUPDATEPROG&yp update
+100029&KEYSERVEPROG&key server
+100030&SECURECMDPROG&secure login
+100031&NETFWDIPROG&nfs net forwarder init
+100032&NETFWDTPROG&nfs net forwarder trans
+100033&SUNLINKMAP_PROG&sunlink MAP
+100034&NETMONPROG&network monitor
+100035&DBASEPROG&lightweight database
+100036&PWDAUTHPROG&password authorization
+100037&TFSPROG&translucent file svc
+100038&NSEPROG&nse server
+100039&NSE_ACTIVATE_PROG&nse activate daemon
+.sp .2i
+150001&PCNFSDPROG&pc passwd authorization
+.sp .2i
+200000&PYRAMIDLOCKINGPROG&Pyramid-locking
+200001&PYRAMIDSYS5&Pyramid-sys5
+200002&CADDS_IMAGE&CV cadds_image
+.sp .2i
+300001&ADT_RFLOCKPROG&ADT file locking
+.TE
+.NH 2
+\&Passing Arbitrary Data Types
+.IX "arbitrary data types"
+.LP
+In the previous example, the RPC call passes a single
+.I "unsigned long"
+RPC can handle arbitrary data structures, regardless of
+different machines' byte orders or structure layout conventions,
+by always converting them to a network standard called
+.I "External Data Representation"
+(XDR) before
+sending them over the wire.
+The process of converting from a particular machine representation
+to XDR format is called
+.I serializing ,
+and the reverse process is called
+.I deserializing .
+The type field parameters of
+.I callrpc()
+and
+.I registerrpc()
+can be a built-in procedure like
+.I xdr_u_long()
+in the previous example, or a user supplied one.
+XDR has these built-in type routines:
+.IX RPC "built-in routines"
+.DS
+.ft CW
+xdr_int()      xdr_u_int()      xdr_enum()
+xdr_long()     xdr_u_long()     xdr_bool()
+xdr_short()    xdr_u_short()    xdr_wrapstring()
+xdr_char()     xdr_u_char()
+.DE
+Note that the routine
+.I xdr_string()
+exists, but cannot be used with
+.I callrpc()
+and
+.I registerrpc (),
+which only pass two parameters to their XDR routines.
+.I xdr_wrapstring()
+has only two parameters, and is thus OK.  It calls
+.I xdr_string ().
+.LP
+As an example of a user-defined type routine,
+if you wanted to send the structure
+.DS
+.ft CW
+struct simple {
+	int a;
+	short b;
+} simple;
+.DE
+then you would call
+.I callrpc()
+as
+.DS
+.ft CW
+callrpc(hostname, PROGNUM, VERSNUM, PROCNUM,
+        xdr_simple, &simple ...);
+.DE
+where
+.I xdr_simple()
+is written as:
+.ie t .DS
+.el .DS L
+.ft CW
+#include <rpc/rpc.h>
+
+xdr_simple(xdrsp, simplep)
+	XDR *xdrsp;
+	struct simple *simplep;
+{
+	if (!xdr_int(xdrsp, &simplep->a))
+		return (0);
+	if (!xdr_short(xdrsp, &simplep->b))
+		return (0);
+	return (1);
+}
+.DE
+.LP
+An XDR routine returns nonzero (true in the sense of C) if it
+completes successfully, and zero otherwise.
+A complete description of XDR is in the
+.I "XDR Protocol Specification"
+section of this manual, only few implementation examples are
+given here.
+.LP
+In addition to the built-in primitives,
+there are also the prefabricated building blocks:
+.DS
+.ft CW
+xdr_array()       xdr_bytes()     xdr_reference()
+xdr_vector()      xdr_union()     xdr_pointer()
+xdr_string()      xdr_opaque()
+.DE
+To send a variable array of integers,
+you might package them up as a structure like this
+.DS
+.ft CW
+struct varintarr {
+	int *data;
+	int arrlnth;
+} arr;
+.DE
+and make an RPC call such as
+.DS
+.ft CW
+callrpc(hostname, PROGNUM, VERSNUM, PROCNUM,
+        xdr_varintarr, &arr...);
+.DE
+with
+.I xdr_varintarr()
+defined as:
+.ie t .DS
+.el .DS L
+.ft CW
+xdr_varintarr(xdrsp, arrp)
+	XDR *xdrsp;
+	struct varintarr *arrp;
+{
+	return (xdr_array(xdrsp, &arrp->data, &arrp->arrlnth,
+		MAXLEN, sizeof(int), xdr_int));
+}
+.DE
+This routine takes as parameters the XDR handle,
+a pointer to the array, a pointer to the size of the array,
+the maximum allowable array size,
+the size of each array element,
+and an XDR routine for handling each array element.
+.KS
+.LP
+If the size of the array is known in advance, one can use
+.I xdr_vector (),
+which serializes fixed-length arrays.
+.ie t .DS
+.el .DS L
+.ft CW
+int intarr[SIZE];
+
+xdr_intarr(xdrsp, intarr)
+	XDR *xdrsp;
+	int intarr[];
+{
+	int i;
+
+	return (xdr_vector(xdrsp, intarr, SIZE, sizeof(int),
+		xdr_int));
+}
+.DE
+.KE
+.LP
+XDR always converts quantities to 4-byte multiples when serializing.
+Thus, if either of the examples above involved characters
+instead of integers, each character would occupy 32 bits.
+That is the reason for the XDR routine
+.I xdr_bytes()
+which is like
+.I xdr_array()
+except that it packs characters;
+.I xdr_bytes()
+has four parameters, similar to the first four parameters of
+.I xdr_array ().
+For null-terminated strings, there is also the
+.I xdr_string()
+routine, which is the same as
+.I xdr_bytes()
+without the length parameter.
+On serializing it gets the string length from
+.I strlen (),
+and on deserializing it creates a null-terminated string.
+.LP
+Here is a final example that calls the previously written
+.I xdr_simple()
+as well as the built-in functions
+.I xdr_string()
+and
+.I xdr_reference (),
+which chases pointers:
+.ie t .DS
+.el .DS L
+.ft CW
+struct finalexample {
+	char *string;
+	struct simple *simplep;
+} finalexample;
+
+xdr_finalexample(xdrsp, finalp)
+	XDR *xdrsp;
+	struct finalexample *finalp;
+{
+
+	if (!xdr_string(xdrsp, &finalp->string, MAXSTRLEN))
+		return (0);
+	if (!xdr_reference(xdrsp, &finalp->simplep,
+	  sizeof(struct simple), xdr_simple);
+		return (0);
+	return (1);
+}
+.DE
+Note that we could as easily call
+.I xdr_simple()
+here instead of
+.I xdr_reference ().
+.NH 1
+\&Lowest Layer of RPC
+.IX "lowest layer of RPC"
+.IX "RPC" "lowest layer"
+.LP
+In the examples given so far,
+RPC takes care of many details automatically for you.
+In this section, we'll show you how you can change the defaults
+by using lower layers of the RPC library.
+It is assumed that you are familiar with sockets
+and the system calls for dealing with them.
+.LP
+There are several occasions when you may need to use lower layers of
+RPC.  First, you may need to use TCP, since the higher layer uses UDP,
+which restricts RPC calls to 8K bytes of data.  Using TCP permits calls
+to send long streams of data.
+For an example, see the
+.I TCP
+section below.  Second, you may want to allocate and free memory
+while serializing or deserializing with XDR routines.
+There is no call at the higher level to let
+you free memory explicitly.
+For more explanation, see the
+.I "Memory Allocation with XDR"
+section below.
+Third, you may need to perform authentication
+on either the client or server side, by supplying
+credentials or verifying them.
+See the explanation in the
+.I Authentication
+section below.
+.NH 2
+\&More on the Server Side
+.IX RPC "server side"
+.LP
+The server for the
+.I nusers()
+program shown below does the same thing as the one using
+.I registerrpc()
+above, but is written using a lower layer of the RPC package:
+.ie t .DS
+.el .DS L
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>
+#include <utmp.h>
+#include <rpcsvc/rusers.h>
+
+main()
+{
+	SVCXPRT *transp;
+	int nuser();
+
+	transp = svcudp_create(RPC_ANYSOCK);
+	if (transp == NULL){
+		fprintf(stderr, "can't create an RPC server\en");
+		exit(1);
+	}
+	pmap_unset(RUSERSPROG, RUSERSVERS);
+	if (!svc_register(transp, RUSERSPROG, RUSERSVERS,
+			  nuser, IPPROTO_UDP)) {
+		fprintf(stderr, "can't register RUSER service\en");
+		exit(1);
+	}
+	svc_run();  /* \fINever returns\fP */
+	fprintf(stderr, "should never reach this point\en");
+}
+
+nuser(rqstp, transp)
+	struct svc_req *rqstp;
+	SVCXPRT *transp;
+{
+	unsigned long nusers;
+
+	switch (rqstp->rq_proc) {
+	case NULLPROC:
+		if (!svc_sendreply(transp, xdr_void, 0))
+			fprintf(stderr, "can't reply to RPC call\en");
+		return;
+	case RUSERSPROC_NUM:
+.ft I
+		/*
+		 * Code here to compute the number of users
+		 * and assign it to the variable \fInusers\fP
+		 */
+.ft CW
+		if (!svc_sendreply(transp, xdr_u_long, &nusers))
+			fprintf(stderr, "can't reply to RPC call\en");
+		return;
+	default:
+		svcerr_noproc(transp);
+		return;
+	}
+}
+.DE
+.LP
+First, the server gets a transport handle, which is used
+for receiving and replying to RPC messages.
+.I registerrpc()
+uses
+.I svcudp_create()
+to get a UDP handle.
+If you require a more reliable protocol, call
+.I svctcp_create()
+instead.
+If the argument to
+.I svcudp_create()
+is
+.I RPC_ANYSOCK
+the RPC library creates a socket
+on which to receive and reply to RPC calls.  Otherwise,
+.I svcudp_create()
+expects its argument to be a valid socket number.
+If you specify your own socket, it can be bound or unbound.
+If it is bound to a port by the user, the port numbers of
+.I svcudp_create()
+and
+.I clnttcp_create()
+(the low-level client routine) must match.
+.LP
+If the user specifies the
+.I RPC_ANYSOCK
+argument, the RPC library routines will open sockets.
+Otherwise they will expect the user to do so.  The routines
+.I svcudp_create()
+and
+.I clntudp_create()
+will cause the RPC library routines to
+.I bind()
+their socket if it is not bound already.
+.LP
+A service may choose to register its port number with the
+local portmapper service.  This is done is done by specifying
+a non-zero protocol number in
+.I svc_register ().
+Incidently, a client can discover the server's port number by
+consulting the portmapper on their server's machine.  This can
+be done automatically by specifying a zero port number in
+.I clntudp_create()
+or
+.I clnttcp_create ().
+.LP
+After creating an
+.I SVCXPRT ,
+the next step is to call
+.I pmap_unset()
+so that if the
+.I nusers()
+server crashed earlier,
+any previous trace of it is erased before restarting.
+More precisely,
+.I pmap_unset()
+erases the entry for
+.I RUSERSPROG
+from the port mapper's tables.
+.LP
+Finally, we associate the program number for
+.I nusers()
+with the procedure
+.I nuser ().
+The final argument to
+.I svc_register()
+is normally the protocol being used,
+which, in this case, is
+.I IPPROTO_UDP
+Notice that unlike
+.I registerrpc (),
+there are no XDR routines involved
+in the registration process.
+Also, registration is done on the program,
+rather than procedure, level.
+.LP
+The user routine
+.I nuser()
+must call and dispatch the appropriate XDR routines
+based on the procedure number.
+Note that
+two things are handled by
+.I nuser()
+that
+.I registerrpc()
+handles automatically.
+The first is that procedure
+.I NULLPROC
+(currently zero) returns with no results.
+This can be used as a simple test
+for detecting if a remote program is running.
+Second, there is a check for invalid procedure numbers.
+If one is detected,
+.I svcerr_noproc()
+is called to handle the error.
+.KS
+.LP
+The user service routine serializes the results and returns
+them to the RPC caller via
+.I svc_sendreply()
+Its first parameter is the
+.I SVCXPRT
+handle, the second is the XDR routine,
+and the third is a pointer to the data to be returned.
+Not illustrated above is how a server
+handles an RPC program that receives data.
+As an example, we can add a procedure
+.I RUSERSPROC_BOOL
+which has an argument
+.I nusers (),
+and returns
+.I TRUE
+or
+.I FALSE
+depending on whether there are nusers logged on.
+It would look like this:
+.ie t .DS
+.el .DS L
+.ft CW
+case RUSERSPROC_BOOL: {
+	int bool;
+	unsigned nuserquery;
+
+	if (!svc_getargs(transp, xdr_u_int, &nuserquery) {
+		svcerr_decode(transp);
+		return;
+	}
+.ft I
+	/*
+	 * Code to set \fInusers\fP = number of users
+	 */
+.ft CW
+	if (nuserquery == nusers)
+		bool = TRUE;
+	else
+		bool = FALSE;
+	if (!svc_sendreply(transp, xdr_bool, &bool)) {
+		 fprintf(stderr, "can't reply to RPC call\en");
+		 return (1);
+	}
+	return;
+}
+.DE
+.KE
+.LP
+The relevant routine is
+.I svc_getargs()
+which takes an
+.I SVCXPRT
+handle, the XDR routine,
+and a pointer to where the input is to be placed as arguments.
+.NH 2
+\&Memory Allocation with XDR
+.IX "memory allocation with XDR"
+.IX XDR "memory allocation"
+.LP
+XDR routines not only do input and output,
+they also do memory allocation.
+This is why the second parameter of
+.I xdr_array()
+is a pointer to an array, rather than the array itself.
+If it is
+.I NULL ,
+then
+.I xdr_array()
+allocates space for the array and returns a pointer to it,
+putting the size of the array in the third argument.
+As an example, consider the following XDR routine
+.I xdr_chararr1()
+which deals with a fixed array of bytes with length
+.I SIZE .
+.ie t .DS
+.el .DS L
+.ft CW
+xdr_chararr1(xdrsp, chararr)
+	XDR *xdrsp;
+	char chararr[];
+{
+	char *p;
+	int len;
+
+	p = chararr;
+	len = SIZE;
+	return (xdr_bytes(xdrsp, &p, &len, SIZE));
+}
+.DE
+If space has already been allocated in
+.I chararr ,
+it can be called from a server like this:
+.ie t .DS
+.el .DS L
+.ft CW
+char chararr[SIZE];
+
+svc_getargs(transp, xdr_chararr1, chararr);
+.DE
+If you want XDR to do the allocation,
+you would have to rewrite this routine in the following way:
+.ie t .DS
+.el .DS L
+.ft CW
+xdr_chararr2(xdrsp, chararrp)
+	XDR *xdrsp;
+	char **chararrp;
+{
+	int len;
+
+	len = SIZE;
+	return (xdr_bytes(xdrsp, charrarrp, &len, SIZE));
+}
+.DE
+Then the RPC call might look like this:
+.ie t .DS
+.el .DS L
+.ft CW
+char *arrptr;
+
+arrptr = NULL;
+svc_getargs(transp, xdr_chararr2, &arrptr);
+.ft I
+/*
+ * Use the result here
+ */
+.ft CW
+svc_freeargs(transp, xdr_chararr2, &arrptr);
+.DE
+Note that, after being used, the character array can be freed with
+.I svc_freeargs()
+.I svc_freeargs()
+will not attempt to free any memory if the variable indicating it
+is NULL.  For example, in the the routine
+.I xdr_finalexample (),
+given earlier, if
+.I finalp->string
+was NULL, then it would not be freed.  The same is true for
+.I finalp->simplep .
+.LP
+To summarize, each XDR routine is responsible
+for serializing, deserializing, and freeing memory.
+When an XDR routine is called from
+.I callrpc()
+the serializing part is used.
+When called from
+.I svc_getargs()
+the deserializer is used.
+And when called from
+.I svc_freeargs()
+the memory deallocator is used.  When building simple examples like those
+in this section, a user doesn't have to worry
+about the three modes.
+See the
+.I "External Data Representation: Sun Technical Notes"
+for examples of more sophisticated XDR routines that determine
+which of the three modes they are in and adjust their behavior accordingly.
+.KS
+.NH 2
+\&The Calling Side
+.IX RPC "calling side"
+.LP
+When you use
+.I callrpc()
+you have no control over the RPC delivery
+mechanism or the socket used to transport the data.
+To illustrate the layer of RPC that lets you adjust these
+parameters, consider the following code to call the
+.I nusers
+service:
+.ie t .DS
+.el .DS L
+.ft CW
+.vs 11
+#include <stdio.h>
+#include <rpc/rpc.h>
+#include <utmp.h>
+#include <rpcsvc/rusers.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <netdb.h>
+
+main(argc, argv)
+	int argc;
+	char **argv;
+{
+	struct hostent *hp;
+	struct timeval pertry_timeout, total_timeout;
+	struct sockaddr_in server_addr;
+	int sock = RPC_ANYSOCK;
+	register CLIENT *client;
+	enum clnt_stat clnt_stat;
+	unsigned long nusers;
+
+	if (argc != 2) {
+		fprintf(stderr, "usage: nusers hostname\en");
+		exit(-1);
+	}
+	if ((hp = gethostbyname(argv[1])) == NULL) {
+		fprintf(stderr, "can't get addr for %s\en",argv[1]);
+		exit(-1);
+	}
+	pertry_timeout.tv_sec = 3;
+	pertry_timeout.tv_usec = 0;
+	bcopy(hp->h_addr, (caddr_t)&server_addr.sin_addr,
+		hp->h_length);
+	server_addr.sin_family = AF_INET;
+	server_addr.sin_port =  0;
+	if ((client = clntudp_create(&server_addr, RUSERSPROG,
+	  RUSERSVERS, pertry_timeout, &sock)) == NULL) {
+		clnt_pcreateerror("clntudp_create");
+		exit(-1);
+	}
+	total_timeout.tv_sec = 20;
+	total_timeout.tv_usec = 0;
+	clnt_stat = clnt_call(client, RUSERSPROC_NUM, xdr_void,
+		0, xdr_u_long, &nusers, total_timeout);
+	if (clnt_stat != RPC_SUCCESS) {
+		clnt_perror(client, "rpc");
+		exit(-1);
+	}
+	clnt_destroy(client);
+	close(sock);
+	exit(0);
+}
+.vs
+.DE
+.KE
+The low-level version of
+.I callrpc()
+is
+.I clnt_call()
+which takes a
+.I CLIENT
+pointer rather than a host name.  The parameters to
+.I clnt_call()
+are a
+.I CLIENT
+pointer, the procedure number,
+the XDR routine for serializing the argument,
+a pointer to the argument,
+the XDR routine for deserializing the return value,
+a pointer to where the return value will be placed,
+and the time in seconds to wait for a reply.
+.LP
+The
+.I CLIENT
+pointer is encoded with the transport mechanism.
+.I callrpc()
+uses UDP, thus it calls
+.I clntudp_create()
+to get a
+.I CLIENT
+pointer.  To get TCP (Transmission Control Protocol), you would use
+.I clnttcp_create() .
+.LP
+The parameters to
+.I clntudp_create()
+are the server address, the program number, the version number,
+a timeout value (between tries), and a pointer to a socket.
+The final argument to
+.I clnt_call()
+is the total time to wait for a response.
+Thus, the number of tries is the
+.I clnt_call()
+timeout divided by the
+.I clntudp_create()
+timeout.
+.LP
+Note that the
+.I clnt_destroy()
+call
+always deallocates the space associated with the
+.I CLIENT
+handle.  It closes the socket associated with the
+.I CLIENT
+handle, however, only if the RPC library opened it.  It the
+socket was opened by the user, it stays open.  This makes it
+possible, in cases where there are multiple client handles
+using the same socket, to destroy one handle without closing
+the socket that other handles are using.
+.LP
+To make a stream connection, the call to
+.I clntudp_create()
+is replaced with a call to
+.I clnttcp_create() .
+.DS
+.ft CW
+clnttcp_create(&server_addr, prognum, versnum, &sock,
+               inputsize, outputsize);
+.DE
+There is no timeout argument; instead, the receive and send buffer
+sizes must be specified.  When the
+.I clnttcp_create()
+call is made, a TCP connection is established.
+All RPC calls using that
+.I CLIENT
+handle would use this connection.
+The server side of an RPC call using TCP has
+.I svcudp_create()
+replaced by
+.I svctcp_create() .
+.DS
+.ft CW
+transp = svctcp_create(RPC_ANYSOCK, 0, 0);
+.DE
+The last two arguments to
+.I svctcp_create()
+are send and receive sizes respectively.  If `0' is specified for
+either of these, the system chooses a reasonable default.
+.KS
+.NH 1
+\&Other RPC Features
+.IX "RPC" "miscellaneous features"
+.IX "miscellaneous RPC features"
+.LP
+This section discusses some other aspects of RPC
+that are occasionally useful.
+.NH 2
+\&Select on the Server Side
+.IX RPC select() RPC \fIselect()\fP
+.IX select() "" \fIselect()\fP "on the server side"
+.LP
+Suppose a process is processing RPC requests
+while performing some other activity.
+If the other activity involves periodically updating a data structure,
+the process can set an alarm signal before calling
+.I svc_run()
+But if the other activity
+involves waiting on a file descriptor, the
+.I svc_run()
+call won't work.
+The code for
+.I svc_run()
+is as follows:
+.ie t .DS
+.el .DS L
+.ft CW
+.vs 11
+void
+svc_run()
+{
+	fd_set readfds;
+	int dtbsz = getdtablesize();
+
+	for (;;) {
+		readfds = svc_fds;
+		switch (select(dtbsz, &readfds, NULL,NULL,NULL)) {
+
+		case -1:
+			if (errno == EINTR)
+				continue;
+			perror("select");
+			return;
+		case 0:
+			break;
+		default:
+			svc_getreqset(&readfds);
+		}
+	}
+}
+.vs
+.DE
+.KE
+.LP
+You can bypass
+.I svc_run()
+and call
+.I svc_getreqset()
+yourself.
+All you need to know are the file descriptors
+of the socket(s) associated with the programs you are waiting on.
+Thus you can have your own
+.I select()
+.IX select() "" \fIselect()\fP
+that waits on both the RPC socket,
+and your own descriptors.  Note that
+.I svc_fds()
+is a bit mask of all the file descriptors that RPC is using for
+services.  It can change everytime that
+.I any
+RPC library routine is called, because descriptors are constantly
+being opened and closed, for example for TCP connections.
+.NH 2
+\&Broadcast RPC
+.IX "broadcast RPC"
+.IX RPC "broadcast"
+.LP
+The
+.I portmapper
+is a daemon that converts RPC program numbers
+into DARPA protocol port numbers; see the
+.I portmap
+man page.  You can't do broadcast RPC without the portmapper.
+Here are the main differences between
+broadcast RPC and normal RPC calls:
+.IP  1.
+Normal RPC expects one answer, whereas
+broadcast RPC expects many answers
+(one or more answer from each responding machine).
+.IP  2.
+Broadcast RPC can only be supported by packet-oriented (connectionless)
+transport protocols like UPD/IP.
+.IP  3.
+The implementation of broadcast RPC
+treats all unsuccessful responses as garbage by filtering them out.
+Thus, if there is a version mismatch between the
+broadcaster and a remote service,
+the user of broadcast RPC never knows.
+.IP  4.
+All broadcast messages are sent to the portmap port.
+Thus, only services that register themselves with their portmapper
+are accessible via the broadcast RPC mechanism.
+.IP  5.
+Broadcast requests are limited in size to the MTU (Maximum Transfer
+Unit) of the local network.  For Ethernet, the MTU is 1500 bytes.
+.KS
+.NH 3
+\&Broadcast RPC Synopsis
+.IX "broadcast RPC" synopsis
+.IX "RPC" "broadcast synopsis"
+.ie t .DS
+.el .DS L
+.ft CW
+#include <rpc/pmap_clnt.h>
+	. . .
+enum clnt_stat	clnt_stat;
+	. . .
+clnt_stat = clnt_broadcast(prognum, versnum, procnum,
+  inproc, in, outproc, out, eachresult)
+	u_long    prognum;        /* \fIprogram number\fP */
+	u_long    versnum;        /* \fIversion number\fP */
+	u_long    procnum;        /* \fIprocedure number\fP */
+	xdrproc_t inproc;         /* \fIxdr routine for args\fP */
+	caddr_t   in;             /* \fIpointer to args\fP */
+	xdrproc_t outproc;        /* \fIxdr routine for results\fP */
+	caddr_t   out;            /* \fIpointer to results\fP */
+	bool_t    (*eachresult)();/* \fIcall with each result gotten\fP */
+.DE
+.KE
+The procedure
+.I eachresult()
+is called each time a valid result is obtained.
+It returns a boolean that indicates
+whether or not the user wants more responses.
+.ie t .DS
+.el .DS L
+.ft CW
+bool_t done;
+	. . .
+done = eachresult(resultsp, raddr)
+	caddr_t resultsp;
+	struct sockaddr_in *raddr; /* \fIAddr of responding machine\fP */
+.DE
+If
+.I done
+is
+.I TRUE ,
+then broadcasting stops and
+.I clnt_broadcast()
+returns successfully.
+Otherwise, the routine waits for another response.
+The request is rebroadcast
+after a few seconds of waiting.
+If no responses come back,
+the routine returns with
+.I RPC_TIMEDOUT .
+.NH 2
+\&Batching
+.IX "batching"
+.IX RPC "batching"
+.LP
+The RPC architecture is designed so that clients send a call message,
+and wait for servers to reply that the call succeeded.
+This implies that clients do not compute
+while servers are processing a call.
+This is inefficient if the client does not want or need
+an acknowledgement for every message sent.
+It is possible for clients to continue computing
+while waiting for a response,
+using RPC batch facilities.
+.LP
+RPC messages can be placed in a \*Qpipeline\*U of calls
+to a desired server; this is called batching.
+Batching assumes that:
+1) each RPC call in the pipeline requires no response from the server,
+and the server does not send a response message; and
+2) the pipeline of calls is transported on a reliable
+byte stream transport such as TCP/IP.
+Since the server does not respond to every call,
+the client can generate new calls in parallel
+with the server executing previous calls.
+Furthermore, the TCP/IP implementation can buffer up
+many call messages, and send them to the server in one
+.I write()
+system call.  This overlapped execution
+greatly decreases the interprocess communication overhead of
+the client and server processes,
+and the total elapsed time of a series of calls.
+.LP
+Since the batched calls are buffered,
+the client should eventually do a nonbatched call
+in order to flush the pipeline.
+.LP
+A contrived example of batching follows.
+Assume a string rendering service (like a window system)
+has two similar calls: one renders a string and returns void results,
+while the other renders a string and remains silent.
+The service (using the TCP/IP transport) may look like:
+.ie t .DS
+.el .DS L
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>
+#include <suntool/windows.h>
+
+void windowdispatch();
+
+main()
+{
+	SVCXPRT *transp;
+
+	transp = svctcp_create(RPC_ANYSOCK, 0, 0);
+	if (transp == NULL){
+		fprintf(stderr, "can't create an RPC server\en");
+		exit(1);
+	}
+	pmap_unset(WINDOWPROG, WINDOWVERS);
+	if (!svc_register(transp, WINDOWPROG, WINDOWVERS,
+	  windowdispatch, IPPROTO_TCP)) {
+		fprintf(stderr, "can't register WINDOW service\en");
+		exit(1);
+	}
+	svc_run();  /* \fINever returns\fP */
+	fprintf(stderr, "should never reach this point\en");
+}
+
+void
+windowdispatch(rqstp, transp)
+	struct svc_req *rqstp;
+	SVCXPRT *transp;
+{
+	char *s = NULL;
+
+	switch (rqstp->rq_proc) {
+	case NULLPROC:
+		if (!svc_sendreply(transp, xdr_void, 0))
+			fprintf(stderr, "can't reply to RPC call\en");
+		return;
+	case RENDERSTRING:
+		if (!svc_getargs(transp, xdr_wrapstring, &s)) {
+			fprintf(stderr, "can't decode arguments\en");
+.ft I
+			/*
+			 * Tell caller he screwed up
+			 */
+.ft CW
+			svcerr_decode(transp);
+			break;
+		}
+.ft I
+		/*
+		 * Code here to render the string \fIs\fP
+		 */
+.ft CW
+		if (!svc_sendreply(transp, xdr_void, NULL))
+			fprintf(stderr, "can't reply to RPC call\en");
+		break;
+	case RENDERSTRING_BATCHED:
+		if (!svc_getargs(transp, xdr_wrapstring, &s)) {
+			fprintf(stderr, "can't decode arguments\en");
+.ft I
+			/*
+			 * We are silent in the face of protocol errors
+			 */
+.ft CW
+			break;
+		}
+.ft I
+		/*
+		 * Code here to render string s, but send no reply!
+		 */
+.ft CW
+		break;
+	default:
+		svcerr_noproc(transp);
+		return;
+	}
+.ft I
+	/*
+	 * Now free string allocated while decoding arguments
+	 */
+.ft CW
+	svc_freeargs(transp, xdr_wrapstring, &s);
+}
+.DE
+Of course the service could have one procedure
+that takes the string and a boolean
+to indicate whether or not the procedure should respond.
+.LP
+In order for a client to take advantage of batching,
+the client must perform RPC calls on a TCP-based transport
+and the actual calls must have the following attributes:
+1) the result's XDR routine must be zero
+.I NULL ),
+and 2) the RPC call's timeout must be zero.
+.KS
+.LP
+Here is an example of a client that uses batching to render a
+bunch of strings; the batching is flushed when the client gets
+a null string (EOF):
+.ie t .DS
+.el .DS L
+.ft CW
+.vs 11
+#include <stdio.h>
+#include <rpc/rpc.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <netdb.h>
+#include <suntool/windows.h>
+
+main(argc, argv)
+	int argc;
+	char **argv;
+{
+	struct hostent *hp;
+	struct timeval pertry_timeout, total_timeout;
+	struct sockaddr_in server_addr;
+	int sock = RPC_ANYSOCK;
+	register CLIENT *client;
+	enum clnt_stat clnt_stat;
+	char buf[1000], *s = buf;
+
+	if ((client = clnttcp_create(&server_addr,
+	  WINDOWPROG, WINDOWVERS, &sock, 0, 0)) == NULL) {
+		perror("clnttcp_create");
+		exit(-1);
+	}
+	total_timeout.tv_sec = 0;
+	total_timeout.tv_usec = 0;
+	while (scanf("%s", s) != EOF) {
+		clnt_stat = clnt_call(client, RENDERSTRING_BATCHED,
+			xdr_wrapstring, &s, NULL, NULL, total_timeout);
+		if (clnt_stat != RPC_SUCCESS) {
+			clnt_perror(client, "batched rpc");
+			exit(-1);
+		}
+	}
+
+	/* \fINow flush the pipeline\fP */
+
+	total_timeout.tv_sec = 20;
+	clnt_stat = clnt_call(client, NULLPROC, xdr_void, NULL,
+		xdr_void, NULL, total_timeout);
+	if (clnt_stat != RPC_SUCCESS) {
+		clnt_perror(client, "rpc");
+		exit(-1);
+	}
+	clnt_destroy(client);
+	exit(0);
+}
+.vs
+.DE
+.KE
+Since the server sends no message,
+the clients cannot be notified of any of the failures that may occur.
+Therefore, clients are on their own when it comes to handling errors.
+.LP
+The above example was completed to render
+all of the (2000) lines in the file
+.I /etc/termcap .
+The rendering service did nothing but throw the lines away.
+The example was run in the following four configurations:
+1) machine to itself, regular RPC;
+2) machine to itself, batched RPC;
+3) machine to another, regular RPC; and
+4) machine to another, batched RPC.
+The results are as follows:
+1) 50 seconds;
+2) 16 seconds;
+3) 52 seconds;
+4) 10 seconds.
+Running
+.I fscanf()
+on
+.I /etc/termcap
+only requires six seconds.
+These timings show the advantage of protocols
+that allow for overlapped execution,
+though these protocols are often hard to design.
+.NH 2
+\&Authentication
+.IX "authentication"
+.IX "RPC" "authentication"
+.LP
+In the examples presented so far,
+the caller never identified itself to the server,
+and the server never required an ID from the caller.
+Clearly, some network services, such as a network filesystem,
+require stronger security than what has been presented so far.
+.LP
+In reality, every RPC call is authenticated by
+the RPC package on the server, and similarly,
+the RPC client package generates and sends authentication parameters.
+Just as different transports (TCP/IP or UDP/IP)
+can be used when creating RPC clients and servers,
+different forms of authentication can be associated with RPC clients;
+the default authentication type used as a default is type
+.I none .
+.LP
+The authentication subsystem of the RPC package is open ended.
+That is, numerous types of authentication are easy to support.
+.NH 3
+\&UNIX Authentication
+.IX "UNIX Authentication"
+.IP "\fIThe Client Side\fP"
+.LP
+When a caller creates a new RPC client handle as in:
+.DS
+.ft CW
+clnt = clntudp_create(address, prognum, versnum,
+		      wait, sockp)
+.DE
+the appropriate transport instance defaults
+the associate authentication handle to be
+.DS
+.ft CW
+clnt->cl_auth = authnone_create();
+.DE
+The RPC client can choose to use
+.I UNIX
+style authentication by setting
+.I clnt\->cl_auth
+after creating the RPC client handle:
+.DS
+.ft CW
+clnt->cl_auth = authunix_create_default();
+.DE
+This causes each RPC call associated with
+.I clnt
+to carry with it the following authentication credentials structure:
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * UNIX style credentials.
+ */
+.ft CW
+struct authunix_parms {
+    u_long  aup_time;       /* \fIcredentials creation time\fP */
+    char    *aup_machname;  /* \fIhost name where client is\fP */
+    int     aup_uid;        /* \fIclient's UNIX effective uid\fP */
+    int     aup_gid;        /* \fIclient's current group id\fP */
+    u_int   aup_len;        /* \fIelement length of aup_gids\fP */
+    int     *aup_gids;      /* \fIarray of groups user is in\fP */
+};
+.DE
+These fields are set by
+.I authunix_create_default()
+by invoking the appropriate system calls.
+Since the RPC user created this new style of authentication,
+the user is responsible for destroying it with:
+.DS
+.ft CW
+auth_destroy(clnt->cl_auth);
+.DE
+This should be done in all cases, to conserve memory.
+.sp
+.IP "\fIThe Server Side\fP"
+.LP
+Service implementors have a harder time dealing with authentication issues
+since the RPC package passes the service dispatch routine a request
+that has an arbitrary authentication style associated with it.
+Consider the fields of a request handle passed to a service dispatch routine:
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * An RPC Service request
+ */
+.ft CW
+struct svc_req {
+    u_long    rq_prog;    	/* \fIservice program number\fP */
+    u_long    rq_vers;    	/* \fIservice protocol vers num\fP */
+    u_long    rq_proc;    	/* \fIdesired procedure number\fP */
+    struct opaque_auth rq_cred; /* \fIraw credentials from wire\fP */
+    caddr_t   rq_clntcred;  /* \fIcredentials (read only)\fP */
+};
+.DE
+The
+.I rq_cred
+is mostly opaque, except for one field of interest:
+the style or flavor of authentication credentials:
+.ie t .DS
+.el .DS L
+.ft I
+/*
+ * Authentication info.  Mostly opaque to the programmer.
+ */
+.ft CW
+struct opaque_auth {
+    enum_t  oa_flavor;  /* \fIstyle of credentials\fP */
+    caddr_t oa_base;    /* \fIaddress of more auth stuff\fP */
+    u_int   oa_length;  /* \fInot to exceed \fIMAX_AUTH_BYTES */
+};
+.DE
+.IX RPC guarantees
+The RPC package guarantees the following
+to the service dispatch routine:
+.IP  1.
+That the request's
+.I rq_cred
+is well formed.  Thus the service implementor may inspect the request's
+.I rq_cred.oa_flavor
+to determine which style of authentication the caller used.
+The service implementor may also wish to inspect the other fields of
+.I rq_cred
+if the style is not one of the styles supported by the RPC package.
+.IP  2.
+That the request's
+.I rq_clntcred
+field is either
+.I NULL
+or points to a well formed structure
+that corresponds to a supported style of authentication credentials.
+Remember that only
+.I unix
+style is currently supported, so (currently)
+.I rq_clntcred
+could be cast to a pointer to an
+.I authunix_parms
+structure.  If
+.I rq_clntcred
+is
+.I NULL ,
+the service implementor may wish to inspect the other (opaque) fields of
+.I rq_cred
+in case the service knows about a new type of authentication
+that the RPC package does not know about.
+.LP
+Our remote users service example can be extended so that
+it computes results for all users except UID 16:
+.ie t .DS
+.el .DS L
+.ft CW
+.vs 11
+nuser(rqstp, transp)
+	struct svc_req *rqstp;
+	SVCXPRT *transp;
+{
+	struct authunix_parms *unix_cred;
+	int uid;
+	unsigned long nusers;
+
+.ft I
+	/*
+	 * we don't care about authentication for null proc
+	 */
+.ft CW
+	if (rqstp->rq_proc == NULLPROC) {
+		if (!svc_sendreply(transp, xdr_void, 0)) {
+			fprintf(stderr, "can't reply to RPC call\en");
+			return (1);
+		 }
+		 return;
+	}
+.ft I
+	/*
+	 * now get the uid
+	 */
+.ft CW
+	switch (rqstp->rq_cred.oa_flavor) {
+	case AUTH_UNIX:
+		unix_cred =
+			(struct authunix_parms *)rqstp->rq_clntcred;
+		uid = unix_cred->aup_uid;
+		break;
+	case AUTH_NULL:
+	default:
+		svcerr_weakauth(transp);
+		return;
+	}
+	switch (rqstp->rq_proc) {
+	case RUSERSPROC_NUM:
+.ft I
+		/*
+		 * make sure caller is allowed to call this proc
+		 */
+.ft CW
+		if (uid == 16) {
+			svcerr_systemerr(transp);
+			return;
+		}
+.ft I
+		/*
+		 * Code here to compute the number of users
+		 * and assign it to the variable \fInusers\fP
+		 */
+.ft CW
+		if (!svc_sendreply(transp, xdr_u_long, &nusers)) {
+			fprintf(stderr, "can't reply to RPC call\en");
+			return (1);
+		}
+		return;
+	default:
+		svcerr_noproc(transp);
+		return;
+	}
+}
+.vs
+.DE
+A few things should be noted here.
+First, it is customary not to check
+the authentication parameters associated with the
+.I NULLPROC
+(procedure number zero).
+Second, if the authentication parameter's type is not suitable
+for your service, you should call
+.I svcerr_weakauth() .
+And finally, the service protocol itself should return status
+for access denied; in the case of our example, the protocol
+does not have such a status, so we call the service primitive
+.I svcerr_systemerr()
+instead.
+.LP
+The last point underscores the relation between
+the RPC authentication package and the services;
+RPC deals only with
+.I authentication
+and not with individual services'
+.I "access control" .
+The services themselves must implement their own access control policies
+and reflect these policies as return statuses in their protocols.
+.NH 2
+\&DES Authentication
+.IX RPC DES
+.IX RPC authentication
+.LP
+UNIX authentication is quite easy to defeat.  Instead of using
+.I authunix_create_default (),
+one can call
+.I authunix_create()
+and then modify the RPC authentication handle it returns by filling in
+whatever user ID and hostname they wish the server to think they have.
+DES authentication is thus recommended for people who want more security
+than UNIX authentication offers.
+.LP
+The details of the DES authentication protocol are complicated and
+are not explained here.
+See
+.I "Remote Procedure Calls: Protocol Specification"
+for the details.
+.LP
+In  order for  DES authentication   to  work, the
+.I keyserv(8c)
+daemon must be running  on both  the  server  and client machines.  The
+users on  these machines  need  public  keys  assigned by  the network
+administrator in  the
+.I publickey(5)
+database.  And,  they  need to have decrypted  their  secret keys
+using  their  login   password.  This automatically happens when one
+logs in using
+.I login(1) ,
+or can be done manually using
+.I keylogin(1) .
+The
+.I "Network Services"
+chapter
+.\" XXX
+explains more how to setup secure networking.
+.sp
+.IP "\fIClient Side\fP"
+.LP
+If a client wishes to use DES authentication, it must set its
+authentication handle appropriately.  Here is an example:
+.DS
+cl->cl_auth =
+	authdes_create(servername, 60, &server_addr, NULL);
+.DE
+The first argument is the network name or \*Qnetname\*U of the owner of
+the server process.  Typically, server processes are root processes
+and their netname can be derived using the following call:
+.DS
+char servername[MAXNETNAMELEN];
+
+host2netname(servername, rhostname, NULL);
+.DE
+Here,
+.I rhostname
+is the hostname of the machine the server process is running on.
+.I host2netname()
+fills in
+.I servername
+to contain this root process's netname.  If the
+server process was run by a regular user, one could use the call
+.I user2netname()
+instead.  Here is an example for a server process with the same user
+ID as the client:
+.DS
+char servername[MAXNETNAMELEN];
+
+user2netname(servername, getuid(), NULL);
+.DE
+The last argument to both of these calls,
+.I user2netname()
+and
+.I host2netname (),
+is the name of the naming domain where the server is located.  The
+.I NULL
+used here means \*Quse the local domain name.\*U
+.LP
+The second argument to
+.I authdes_create()
+is a lifetime for the credential.  Here it is set to sixty
+seconds.  What that means is that the credential will expire 60
+seconds from now.  If some mischievous user tries to reuse the
+credential, the server RPC subsystem will recognize that it has
+expired and not grant any requests.  If the same mischievous user
+tries to reuse the credential within the sixty second lifetime,
+he will still be rejected because the server RPC subsystem
+remembers which credentials it has already seen in the near past,
+and will not grant requests to duplicates.
+.LP
+The third argument to
+.I authdes_create()
+is the address of the host to synchronize with.  In order for DES
+authentication to work, the server and client must agree upon the
+time.  Here we pass the address of the server itself, so the
+client and server will both be using the same time: the server's
+time.  The argument can be
+.I NULL ,
+which means \*Qdon't bother synchronizing.\*U You should only do this
+if you are sure the client and server are already synchronized.
+.LP
+The final argument to
+.I authdes_create()
+is the address of a DES encryption key to use for encrypting
+timestamps and data.  If this argument is
+.I NULL ,
+as it is in this example, a random key will be chosen.  The client
+may find out the encryption key being used by consulting the
+.I ah_key
+field of the authentication handle.
+.sp
+.IP "\fIServer Side\fP"
+.LP
+The server side is a lot simpler than the client side.  Here is the
+previous example rewritten to use
+.I AUTH_DES
+instead of
+.I AUTH_UNIX :
+.ie t .DS
+.el .DS L
+.ft CW
+.vs 11
+#include <sys/time.h>
+#include <rpc/auth_des.h>
+	. . .
+	. . .
+nuser(rqstp, transp)
+	struct svc_req *rqstp;
+	SVCXPRT *transp;
+{
+	struct authdes_cred *des_cred;
+	int uid;
+	int gid;
+	int gidlen;
+	int gidlist[10];
+.ft I
+	/*
+	 * we don't care about authentication for null proc
+	 */
+.ft CW
+
+	if (rqstp->rq_proc == NULLPROC) {
+		/* \fIsame as before\fP */
+	}
+
+.ft I
+	/*
+	 * now get the uid
+	 */
+.ft CW
+	switch (rqstp->rq_cred.oa_flavor) {
+	case AUTH_DES:
+		des_cred =
+			(struct authdes_cred *) rqstp->rq_clntcred;
+		if (! netname2user(des_cred->adc_fullname.name,
+			&uid, &gid, &gidlen, gidlist))
+		{
+			fprintf(stderr, "unknown user: %s\en",
+				des_cred->adc_fullname.name);
+			svcerr_systemerr(transp);
+			return;
+		}
+		break;
+	case AUTH_NULL:
+	default:
+		svcerr_weakauth(transp);
+		return;
+	}
+
+.ft I
+	/*
+	 * The rest is the same as before
+ 	 */
+.ft CW
+.vs
+.DE
+Note the use of the routine
+.I netname2user (),
+the inverse of
+.I user2netname ():
+it takes a network ID and converts to a unix ID.
+.I netname2user ()
+also supplies the group IDs which we don't use in this example,
+but which may be useful to other UNIX programs.
+.NH 2
+\&Using Inetd
+.IX inetd "" "using \fIinetd\fP"
+.LP
+An RPC server can be started from
+.I inetd
+The only difference from the usual code is that the service
+creation routine should be called in the following form:
+.ie t .DS
+.el .DS L
+.ft CW
+transp = svcudp_create(0);     /* \fIFor UDP\fP */
+transp = svctcp_create(0,0,0); /* \fIFor listener TCP sockets\fP */
+transp = svcfd_create(0,0,0);  /* \fIFor connected TCP sockets\fP */
+.DE
+since
+.I inet
+passes a socket as file descriptor 0.
+Also,
+.I svc_register()
+should be called as
+.ie t .DS
+.el .DS L
+.ft CW
+svc_register(transp, PROGNUM, VERSNUM, service, 0);
+.DE
+with the final flag as 0,
+since the program would already be registered by
+.I inetd
+Remember that if you want to exit
+from the server process and return control to
+.I inet
+you need to explicitly exit, since
+.I svc_run()
+never returns.
+.LP
+The format of entries in
+.I /etc/inetd.conf
+for RPC services is in one of the following two forms:
+.ie t .DS
+.el .DS L
+.ft CW
+p_name/version dgram  rpc/udp wait/nowait user server args
+p_name/version stream rpc/tcp wait/nowait user server args
+.DE
+where
+.I p_name
+is the symbolic name of the program as it appears in
+.I rpc(5) ,
+.I server
+is the program implementing the server,
+and
+.I program
+and
+.I version
+are the program and version numbers of the service.
+For more information, see
+.I inetd.conf(5) .
+.LP
+If the same program handles multiple versions,
+then the version number can be a range,
+as in this example:
+.ie t .DS
+.el .DS L
+.ft CW
+rstatd/1-2 dgram rpc/udp wait root /usr/etc/rpc.rstatd
+.DE
+.NH 1
+\&More Examples
+.sp 1
+.NH 2
+\&Versions
+.IX "versions"
+.IX "RPC" "versions"
+.LP
+By convention, the first version number of program
+.I PROG
+is
+.I PROGVERS_ORIG
+and the most recent version is
+.I PROGVERS
+Suppose there is a new version of the
+.I user
+program that returns an
+.I "unsigned short"
+rather than a
+.I long .
+If we name this version
+.I RUSERSVERS_SHORT
+then a server that wants to support both versions
+would do a double register.
+.ie t .DS
+.el .DS L
+.ft CW
+if (!svc_register(transp, RUSERSPROG, RUSERSVERS_ORIG,
+  nuser, IPPROTO_TCP)) {
+	fprintf(stderr, "can't register RUSER service\en");
+	exit(1);
+}
+if (!svc_register(transp, RUSERSPROG, RUSERSVERS_SHORT,
+  nuser, IPPROTO_TCP)) {
+	fprintf(stderr, "can't register RUSER service\en");
+	exit(1);
+}
+.DE
+Both versions can be handled by the same C procedure:
+.ie t .DS
+.el .DS L
+.ft CW
+.vs 11
+nuser(rqstp, transp)
+	struct svc_req *rqstp;
+	SVCXPRT *transp;
+{
+	unsigned long nusers;
+	unsigned short nusers2;
+
+	switch (rqstp->rq_proc) {
+	case NULLPROC:
+		if (!svc_sendreply(transp, xdr_void, 0)) {
+			fprintf(stderr, "can't reply to RPC call\en");
+            return (1);
+		}
+		return;
+	case RUSERSPROC_NUM:
+.ft I
+		/*
+         * Code here to compute the number of users
+         * and assign it to the variable \fInusers\fP
+		 */
+.ft CW
+		nusers2 = nusers;
+		switch (rqstp->rq_vers) {
+		case RUSERSVERS_ORIG:
+            if (!svc_sendreply(transp, xdr_u_long,
+		    &nusers)) {
+                fprintf(stderr,"can't reply to RPC call\en");
+			}
+			break;
+		case RUSERSVERS_SHORT:
+            if (!svc_sendreply(transp, xdr_u_short,
+		    &nusers2)) {
+                fprintf(stderr,"can't reply to RPC call\en");
+			}
+			break;
+		}
+	default:
+		svcerr_noproc(transp);
+		return;
+	}
+}
+.vs
+.DE
+.KS
+.NH 2
+\&TCP
+.IX "TCP"
+.LP
+Here is an example that is essentially
+.I rcp.
+The initiator of the RPC
+.I snd
+call takes its standard input and sends it to the server
+.I rcv
+which prints it on standard output.
+The RPC call uses TCP.
+This also illustrates an XDR procedure that behaves differently
+on serialization than on deserialization.
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+ * The xdr routine:
+ *		on decode, read from wire, write onto fp
+ *		on encode, read from fp, write onto wire
+ */
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>
+
+xdr_rcp(xdrs, fp)
+	XDR *xdrs;
+	FILE *fp;
+{
+	unsigned long size;
+	char buf[BUFSIZ], *p;
+
+	if (xdrs->x_op == XDR_FREE)/* nothing to free */
+		return 1;
+	while (1) {
+		if (xdrs->x_op == XDR_ENCODE) {
+			if ((size = fread(buf, sizeof(char), BUFSIZ,
+			  fp)) == 0 && ferror(fp)) {
+				fprintf(stderr, "can't fread\en");
+				return (1);
+			}
+		}
+		p = buf;
+		if (!xdr_bytes(xdrs, &p, &size, BUFSIZ))
+			return 0;
+		if (size == 0)
+			return 1;
+		if (xdrs->x_op == XDR_DECODE) {
+			if (fwrite(buf, sizeof(char), size,
+			  fp) != size) {
+				fprintf(stderr, "can't fwrite\en");
+				return (1);
+			}
+		}
+	}
+}
+.vs
+.DE
+.KE
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+ * The sender routines
+ */
+.ft CW
+#include <stdio.h>
+#include <netdb.h>
+#include <rpc/rpc.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+
+main(argc, argv)
+	int argc;
+	char **argv;
+{
+	int xdr_rcp();
+	int err;
+
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s servername\en", argv[0]);
+		exit(-1);
+	}
+	if ((err = callrpctcp(argv[1], RCPPROG, RCPPROC,
+	  RCPVERS, xdr_rcp, stdin, xdr_void, 0) != 0)) {
+		clnt_perrno(err);
+		fprintf(stderr, "can't make RPC call\en");
+		exit(1);
+	}
+	exit(0);
+}
+
+callrpctcp(host, prognum, procnum, versnum,
+           inproc, in, outproc, out)
+	char *host, *in, *out;
+	xdrproc_t inproc, outproc;
+{
+	struct sockaddr_in server_addr;
+	int socket = RPC_ANYSOCK;
+	enum clnt_stat clnt_stat;
+	struct hostent *hp;
+	register CLIENT *client;
+	struct timeval total_timeout;
+
+	if ((hp = gethostbyname(host)) == NULL) {
+		fprintf(stderr, "can't get addr for '%s'\en", host);
+		return (-1);
+	}
+	bcopy(hp->h_addr, (caddr_t)&server_addr.sin_addr,
+		hp->h_length);
+	server_addr.sin_family = AF_INET;
+	server_addr.sin_port =  0;
+	if ((client = clnttcp_create(&server_addr, prognum,
+	  versnum, &socket, BUFSIZ, BUFSIZ)) == NULL) {
+		perror("rpctcp_create");
+		return (-1);
+	}
+	total_timeout.tv_sec = 20;
+	total_timeout.tv_usec = 0;
+	clnt_stat = clnt_call(client, procnum,
+		inproc, in, outproc, out, total_timeout);
+	clnt_destroy(client);
+	return (int)clnt_stat;
+}
+.vs
+.DE
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+ * The receiving routines
+ */
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>
+
+main()
+{
+	register SVCXPRT *transp;
+     int rcp_service(), xdr_rcp();
+
+	if ((transp = svctcp_create(RPC_ANYSOCK,
+	  BUFSIZ, BUFSIZ)) == NULL) {
+		fprintf("svctcp_create: error\en");
+		exit(1);
+	}
+	pmap_unset(RCPPROG, RCPVERS);
+	if (!svc_register(transp,
+	  RCPPROG, RCPVERS, rcp_service, IPPROTO_TCP)) {
+		fprintf(stderr, "svc_register: error\en");
+		exit(1);
+	}
+	svc_run();  /* \fInever returns\fP */
+	fprintf(stderr, "svc_run should never return\en");
+}
+
+rcp_service(rqstp, transp)
+	register struct svc_req *rqstp;
+	register SVCXPRT *transp;
+{
+	switch (rqstp->rq_proc) {
+	case NULLPROC:
+		if (svc_sendreply(transp, xdr_void, 0) == 0) {
+			fprintf(stderr, "err: rcp_service");
+			return (1);
+		}
+		return;
+	case RCPPROC_FP:
+		if (!svc_getargs(transp, xdr_rcp, stdout)) {
+			svcerr_decode(transp);
+			return;
+		}
+		if (!svc_sendreply(transp, xdr_void, 0)) {
+			fprintf(stderr, "can't reply\en");
+			return;
+		}
+		return (0);
+	default:
+		svcerr_noproc(transp);
+		return;
+	}
+}
+.vs
+.DE
+.NH 2
+\&Callback Procedures
+.IX RPC "callback procedures"
+.LP
+Occasionally, it is useful to have a server become a client,
+and make an RPC call back to the process which is its client.
+An example is remote debugging,
+where the client is a window system program,
+and the server is a debugger running on the remote machine.
+Most of the time,
+the user clicks a mouse button at the debugging window,
+which converts this to a debugger command,
+and then makes an RPC call to the server
+(where the debugger is actually running),
+telling it to execute that command.
+However, when the debugger hits a breakpoint, the roles are reversed,
+and the debugger wants to make an rpc call to the window program,
+so that it can inform the user that a breakpoint has been reached.
+.LP
+In order to do an RPC callback,
+you need a program number to make the RPC call on.
+Since this will be a dynamically generated program number,
+it should be in the transient range,
+.I "0x40000000 - 0x5fffffff" .
+The routine
+.I gettransient()
+returns a valid program number in the transient range,
+and registers it with the portmapper.
+It only talks to the portmapper running on the same machine as the
+.I gettransient()
+routine itself.  The call to
+.I pmap_set()
+is a test and set operation,
+in that it indivisibly tests whether a program number
+has already been registered,
+and if it has not, then reserves it.  On return, the
+.I sockp
+argument will contain a socket that can be used
+as the argument to an
+.I svcudp_create()
+or
+.I svctcp_create()
+call.
+.ie t .DS
+.el .DS L
+.ft CW
+.vs 11
+#include <stdio.h>
+#include <rpc/rpc.h>
+#include <sys/socket.h>
+
+gettransient(proto, vers, sockp)
+	int proto, vers, *sockp;
+{
+	static int prognum = 0x40000000;
+	int s, len, socktype;
+	struct sockaddr_in addr;
+
+	switch(proto) {
+		case IPPROTO_UDP:
+			socktype = SOCK_DGRAM;
+			break;
+		case IPPROTO_TCP:
+			socktype = SOCK_STREAM;
+			break;
+		default:
+			fprintf(stderr, "unknown protocol type\en");
+			return 0;
+	}
+	if (*sockp == RPC_ANYSOCK) {
+		if ((s = socket(AF_INET, socktype, 0)) < 0) {
+			perror("socket");
+			return (0);
+		}
+		*sockp = s;
+	}
+	else
+		s = *sockp;
+	addr.sin_addr.s_addr = 0;
+	addr.sin_family = AF_INET;
+	addr.sin_port = 0;
+	len = sizeof(addr);
+.ft I
+	/*
+	 * may be already bound, so don't check for error
+	 */
+.ft CW
+	bind(s, &addr, len);
+	if (getsockname(s, &addr, &len)< 0) {
+		perror("getsockname");
+		return (0);
+	}
+	while (!pmap_set(prognum++, vers, proto,
+		ntohs(addr.sin_port))) continue;
+	return (prognum-1);
+}
+.vs
+.DE
+.SH
+Note:
+.I
+The call to
+.I ntohs()
+is necessary to ensure that the port number in
+.I "addr.sin_port" ,
+which is in
+.I network
+byte order, is passed in
+.I host
+byte order (as
+.I pmap_set()
+expects).  See the
+.I byteorder(3N)
+man page for more details on the conversion of network
+addresses from network to host byte order.
+.KS
+.LP
+The following pair of programs illustrate how to use the
+.I gettransient()
+routine.
+The client makes an RPC call to the server,
+passing it a transient program number.
+Then the client waits around to receive a callback
+from the server at that program number.
+The server registers the program
+.I EXAMPLEPROG
+so that it can receive the RPC call
+informing it of the callback program number.
+Then at some random time (on receiving an
+.I ALRM
+signal in this example), it sends a callback RPC call,
+using the program number it received earlier.
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+ * client
+ */
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>
+
+int callback();
+char hostname[256];
+
+main()
+{
+	int x, ans, s;
+	SVCXPRT *xprt;
+
+	gethostname(hostname, sizeof(hostname));
+	s = RPC_ANYSOCK;
+	x = gettransient(IPPROTO_UDP, 1, &s);
+	fprintf(stderr, "client gets prognum %d\en", x);
+	if ((xprt = svcudp_create(s)) == NULL) {
+	  fprintf(stderr, "rpc_server: svcudp_create\en");
+		exit(1);
+	}
+.ft I
+	/* protocol is 0 - gettransient does registering
+	 */
+.ft CW
+	(void)svc_register(xprt, x, 1, callback, 0);
+	ans = callrpc(hostname, EXAMPLEPROG, EXAMPLEVERS,
+		EXAMPLEPROC_CALLBACK, xdr_int, &x, xdr_void, 0);
+	if ((enum clnt_stat) ans != RPC_SUCCESS) {
+		fprintf(stderr, "call: ");
+		clnt_perrno(ans);
+		fprintf(stderr, "\en");
+	}
+	svc_run();
+	fprintf(stderr, "Error: svc_run shouldn't return\en");
+}
+
+callback(rqstp, transp)
+	register struct svc_req *rqstp;
+	register SVCXPRT *transp;
+{
+	switch (rqstp->rq_proc) {
+		case 0:
+			if (!svc_sendreply(transp, xdr_void, 0)) {
+				fprintf(stderr, "err: exampleprog\en");
+				return (1);
+			}
+			return (0);
+		case 1:
+			if (!svc_getargs(transp, xdr_void, 0)) {
+				svcerr_decode(transp);
+				return (1);
+			}
+			fprintf(stderr, "client got callback\en");
+			if (!svc_sendreply(transp, xdr_void, 0)) {
+				fprintf(stderr, "err: exampleprog");
+				return (1);
+			}
+	}
+}
+.vs
+.DE
+.KE
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+ * server
+ */
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>
+#include <sys/signal.h>
+
+char *getnewprog();
+char hostname[256];
+int docallback();
+int pnum;		/* \fIprogram number for callback routine\fP */
+
+main()
+{
+	gethostname(hostname, sizeof(hostname));
+	registerrpc(EXAMPLEPROG, EXAMPLEVERS,
+	  EXAMPLEPROC_CALLBACK, getnewprog, xdr_int, xdr_void);
+	fprintf(stderr, "server going into svc_run\en");
+	signal(SIGALRM, docallback);
+	alarm(10);
+	svc_run();
+	fprintf(stderr, "Error: svc_run shouldn't return\en");
+}
+
+char *
+getnewprog(pnump)
+	char *pnump;
+{
+	pnum = *(int *)pnump;
+	return NULL;
+}
+
+docallback()
+{
+	int ans;
+
+	ans = callrpc(hostname, pnum, 1, 1, xdr_void, 0,
+		xdr_void, 0);
+	if (ans != 0) {
+		fprintf(stderr, "server: ");
+		clnt_perrno(ans);
+		fprintf(stderr, "\en");
+	}
+}
+.vs
+.DE
diff --git a/share/doc/psd/23.rpc/stubs b/share/doc/psd/23.rpc/stubs
new file mode 100644
index 0000000..78b0a2c
--- /dev/null
+++ b/share/doc/psd/23.rpc/stubs
@@ -0,0 +1,3 @@
+.\" $FreeBSD$
+.\"
+.if t .ftr L CR
diff --git a/share/doc/psd/24.xdr/Makefile b/share/doc/psd/24.xdr/Makefile
index 878dca1..8e30711 100644
--- a/share/doc/psd/24.xdr/Makefile
+++ b/share/doc/psd/24.xdr/Makefile
@@ -4,6 +4,5 @@ VOLUME=		psd/24.xdr
 SRCS=		stubs xdr.nts.ms
 MACROS=		-ms
 USE_EQN=
-SRCDIR=		${.CURDIR}/../../../../lib/libc/rpc/PSD.doc
 
 .include <bsd.doc.mk>
diff --git a/share/doc/psd/24.xdr/stubs b/share/doc/psd/24.xdr/stubs
new file mode 100644
index 0000000..78b0a2c
--- /dev/null
+++ b/share/doc/psd/24.xdr/stubs
@@ -0,0 +1,3 @@
+.\" $FreeBSD$
+.\"
+.if t .ftr L CR
diff --git a/share/doc/psd/24.xdr/xdr.nts.ms b/share/doc/psd/24.xdr/xdr.nts.ms
new file mode 100644
index 0000000..260c7f3
--- /dev/null
+++ b/share/doc/psd/24.xdr/xdr.nts.ms
@@ -0,0 +1,1968 @@
+.\"
+.\" Must use --  eqn -- with this one
+.\"
+.\" @(#)xdr.nts.ms	2.2 88/08/05 4.0 RPCSRC
+.\" $FreeBSD$
+.\"
+.EQ
+delim $$
+.EN
+.de BT
+.if \\n%=1 .tl ''- % -''
+..
+.ND
+.\" prevent excess underlining in nroff
+.if n .fp 2 R
+.OH 'External Data Representation: Sun Technical Notes''Page %'
+.EH 'Page %''External Data Representation: Sun Technical Notes'
+.if \n%=1 .bp
+.SH
+\&External Data Representation: Sun Technical Notes
+.IX XDR "Sun technical notes"
+.LP
+This chapter contains technical notes on Sun's implementation of the
+External Data Representation (XDR) standard, a set of library routines
+that allow a C programmer to describe arbitrary data structures in a
+machinex-independent fashion.
+For a formal specification of the XDR
+standard, see the
+.I "External Data Representation Standard: Protocol Specification".
+XDR is the backbone of Sun's Remote Procedure Call package, in the
+sense that data for remote procedure calls is transmitted using the
+standard.  XDR library routines should be used to transmit data
+that is accessed (read or written) by more than one type of machine.\**
+.FS
+.IX XDR "system routines"
+For a compete specification of the system External Data Representation
+routines, see the
+.I xdr(3N)
+manual page.
+.FE
+.LP
+This chapter contains a short tutorial overview of the XDR library
+routines, a guide to accessing currently available XDR streams, and
+information on defining new streams and data types.  XDR was designed
+to work across different languages, operating systems, and machine
+architectures.  Most users (particularly RPC users) will only need
+the information in the
+.I "Number Filters",
+.I "Floating Point Filters",
+and
+.I "Enumeration Filters"
+sections.
+Programmers wishing to implement RPC and XDR on new machines
+will be interested in the rest of the chapter, as well as the
+.I "External Data Representaiton Standard: Protocol Specification",
+which will be their primary reference.
+.SH
+Note:
+.I
+.I rpcgen
+can be used to write XDR routines even in cases where no RPC calls are
+being made.
+.LP
+On Sun systems,
+C programs that want to use XDR routines
+must include the file
+.I <rpc/rpc.h> ,
+which contains all the necessary interfaces to the XDR system.
+Since the C library
+.I libc.a
+contains all the XDR routines,
+compile as normal.
+.DS
+example% \fBcc\0\fIprogram\fP.c\fI
+.DE
+.ne 3i
+.NH 0
+\&Justification
+.IX XDR justification
+.LP
+Consider the following two programs,
+.I writer :
+.ie t .DS
+.el .DS L
+.ft CW
+#include <stdio.h>
+.sp .5
+main()			/* \fIwriter.c\fP */
+{
+	long i;
+.sp .5
+	for (i = 0; i < 8; i++) {
+		if (fwrite((char *)&i, sizeof(i), 1, stdout) != 1) {
+			fprintf(stderr, "failed!\en");
+			exit(1);
+		}
+	}
+	exit(0);
+}
+.DE
+and
+.I reader :
+.ie t .DS
+.el .DS L
+.ft CW
+#include <stdio.h>
+.sp .5
+main()			/* \fIreader.c\fP */
+{
+	long i, j;
+.sp .5
+	for (j = 0; j < 8; j++) {
+		if (fread((char *)&i, sizeof (i), 1, stdin) != 1) {
+			fprintf(stderr, "failed!\en");
+			exit(1);
+		}
+		printf("%ld ", i);
+	}
+	printf("\en");
+	exit(0);
+}
+.DE
+The two programs appear to be portable, because (a) they pass
+.I lint
+checking, and (b) they exhibit the same behavior when executed
+on two different hardware architectures, a Sun and a VAX.
+.LP
+Piping the output of the
+.I writer
+program to the
+.I reader
+program gives identical results on a Sun or a VAX.
+.DS
+.ft CW
+sun% \fBwriter | reader\fP
+0 1 2 3 4 5 6 7
+sun%
+
+
+vax% \fBwriter | reader\fP
+0 1 2 3 4 5 6 7
+vax%
+.DE
+With the advent of local area networks and 4.2BSD came the concept
+of \*Qnetwork pipes\*U \(em a process produces data on one machine,
+and a second process consumes data on another machine.
+A network pipe can be constructed with
+.I writer
+and
+.I reader .
+Here are the results if the first produces data on a Sun,
+and the second consumes data on a VAX.
+.DS
+.ft CW
+sun% \fBwriter | rsh vax reader\fP
+0 16777216 33554432 50331648 67108864 83886080 100663296
+117440512
+sun%
+.DE
+Identical results can be obtained by executing
+.I writer
+on the VAX and
+.I reader
+on the Sun.  These results occur because the byte ordering
+of long integers differs between the VAX and the Sun,
+even though word size is the same.
+Note that $16777216$ is $2 sup 24$ \(em
+when four bytes are reversed, the 1 winds up in the 24th bit.
+.LP
+Whenever data is shared by two or more machine types, there is
+a need for portable data.  Programs can be made data-portable by
+replacing the
+.I read()
+and
+.I write()
+calls with calls to an XDR library routine
+.I xdr_long() ,
+a filter that knows the standard representation
+of a long integer in its external form.
+Here are the revised versions of
+.I writer :
+.ie t .DS
+.el .DS L
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>	/* \fIxdr is a sub-library of rpc\fP */
+.sp .5
+main()		/* \fIwriter.c\fP */
+{
+	XDR xdrs;
+	long i;
+.sp .5
+	xdrstdio_create(&xdrs, stdout, XDR_ENCODE);
+	for (i = 0; i < 8; i++) {
+		if (!xdr_long(&xdrs, &i)) {
+			fprintf(stderr, "failed!\en");
+			exit(1);
+		}
+	}
+	exit(0);
+}
+.DE
+and
+.I reader :
+.ie t .DS
+.el .DS L
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>	/* \fIxdr is a sub-library of rpc\fP */
+.sp .5
+main()		/* \fIreader.c\fP */
+{
+	XDR xdrs;
+	long i, j;
+.sp .5
+	xdrstdio_create(&xdrs, stdin, XDR_DECODE);
+	for (j = 0; j < 8; j++) {
+		if (!xdr_long(&xdrs, &i)) {
+			fprintf(stderr, "failed!\en");
+			exit(1);
+		}
+		printf("%ld ", i);
+	}
+	printf("\en");
+	exit(0);
+}
+.DE
+The new programs were executed on a Sun,
+on a VAX, and from a Sun to a VAX;
+the results are shown below.
+.DS
+.ft CW
+sun% \fBwriter | reader\fP
+0 1 2 3 4 5 6 7
+sun%
+
+vax% \fBwriter | reader\fP
+0 1 2 3 4 5 6 7
+vax%
+
+sun% \fBwriter | rsh vax reader\fP
+0 1 2 3 4 5 6 7
+sun%
+.DE
+.SH
+Note:
+.I
+.IX XDR "portable data"
+Integers are just the tip of the portable-data iceberg.  Arbitrary
+data structures present portability problems, particularly with
+respect to alignment and pointers.  Alignment on word boundaries
+may cause the size of a structure to vary from machine to machine.
+And pointers, which are very convenient to use, have no meaning
+outside the machine where they are defined.
+.LP
+.NH 1
+\&A Canonical Standard
+.IX XDR "canonical standard"
+.LP
+XDR's approach to standardizing data representations is
+.I canonical .
+That is, XDR defines a single byte order (Big Endian), a single
+floating-point representation (IEEE), and so on.  Any program running on
+any machine can use XDR to create portable data by translating its
+local representation to the XDR standard representations; similarly, any
+program running on any machine can read portable data by translating the
+XDR standard representaions to its local equivalents.  The single standard
+completely decouples programs that create or send portable data from those
+that use or receive portable data.  The advent of a new machine or a new
+language has no effect upon the community of existing portable data creators
+and users.  A new machine joins this community by being \*Qtaught\*U how to
+convert the standard representations and its local representations; the
+local representations of other machines are irrelevant.  Conversely, to
+existing programs running on other machines, the local representations of
+the new machine are also irrelevant; such programs can immediately read
+portable data produced by the new machine because such data conforms to the
+canonical standards that they already understand.
+.LP
+There are strong precedents for XDR's canonical approach.  For example,
+TCP/IP, UDP/IP, XNS, Ethernet, and, indeed, all protocols below layer five
+of the ISO model, are canonical protocols.  The advantage of any canonical
+approach is simplicity; in the case of XDR, a single set of conversion
+routines is written once and is never touched again.  The canonical approach
+has a disadvantage, but it is unimportant in real-world data transfer
+applications.  Suppose two Little-Endian machines are transferring integers
+according to the XDR standard.  The sending machine converts the integers
+from Little-Endian byte order to XDR (Big-Endian) byte order; the receiving
+machine performs the reverse conversion.  Because both machines observe the
+same byte order, their conversions are unnecessary.  The point, however, is
+not necessity, but cost as compared to the alternative.
+.LP
+The time spent converting to and from a canonical representation is
+insignificant, especially in networking applications.  Most of the time
+required to prepare a data structure for transfer is not spent in conversion
+but in traversing the elements of the data structure.  To transmit a tree,
+for example, each leaf must be visited and each element in a leaf record must
+be copied to a buffer and aligned there; storage for the leaf may have to be
+deallocated as well.  Similarly, to receive a tree, storage must be
+allocated for each leaf, data must be moved from the buffer to the leaf and
+properly aligned, and pointers must be constructed to link the leaves
+together.  Every machine pays the cost of traversing and copying data
+structures whether or not conversion is required.  In networking
+applications, communications overhead\(emthe time required to move the data
+down through the sender's protocol layers, across the network and up through
+the receiver's protocol layers\(emdwarfs conversion overhead.
+.NH 1
+\&The XDR Library
+.IX "XDR" "library"
+.LP
+The XDR library not only solves data portability problems, it also
+allows you to write and read arbitrary C constructs in a consistent,
+specified, well-documented manner.  Thus, it can make sense to use the
+library even when the data is not shared among machines on a network.
+.LP
+The XDR library has filter routines for
+strings (null-terminated arrays of bytes),
+structures, unions, and arrays, to name a few.
+Using more primitive routines,
+you can write your own specific XDR routines
+to describe arbitrary data structures,
+including elements of arrays, arms of unions,
+or objects pointed at from other structures.
+The structures themselves may contain arrays of arbitrary elements,
+or pointers to other structures.
+.LP
+Let's examine the two programs more closely.
+There is a family of XDR stream creation routines
+in which each member treats the stream of bits differently.
+In our example, data is manipulated using standard I/O routines,
+so we use
+.I xdrstdio_create ().
+.IX xdrstdio_create() "" "\fIxdrstdio_create()\fP"
+The parameters to XDR stream creation routines
+vary according to their function.
+In our example,
+.I xdrstdio_create()
+takes a pointer to an XDR structure that it initializes,
+a pointer to a
+.I FILE
+that the input or output is performed on, and the operation.
+The operation may be
+.I XDR_ENCODE
+for serializing in the
+.I writer
+program, or
+.I XDR_DECODE
+for deserializing in the
+.I reader
+program.
+.LP
+Note: RPC users never need to create XDR streams;
+the RPC system itself creates these streams,
+which are then passed to the users.
+.LP
+The
+.I xdr_long()
+.IX xdr_long() "" "\fIxdr_long()\fP"
+primitive is characteristic of most XDR library
+primitives and all client XDR routines.
+First, the routine returns
+.I FALSE
+(0) if it fails, and
+.I TRUE
+(1) if it succeeds.
+Second, for each data type,
+.I xxx ,
+there is an associated XDR routine of the form:
+.DS
+.ft CW
+xdr_xxx(xdrs, xp)
+	XDR *xdrs;
+	xxx *xp;
+{
+}
+.DE
+In our case,
+.I xxx
+is long, and the corresponding XDR routine is
+a primitive,
+.I xdr_long() .
+The client could also define an arbitrary structure
+.I xxx
+in which case the client would also supply the routine
+.I xdr_xxx (),
+describing each field by calling XDR routines
+of the appropriate type.
+In all cases the first parameter,
+.I xdrs
+can be treated as an opaque handle,
+and passed to the primitive routines.
+.LP
+XDR routines are direction independent;
+that is, the same routines are called to serialize or deserialize data.
+This feature is critical to software engineering of portable data.
+The idea is to call the same routine for either operation \(em
+this almost guarantees that serialized data can also be deserialized.
+One routine is used by both producer and consumer of networked data.
+This is implemented by always passing the address
+of an object rather than the object itself \(em
+only in the case of deserialization is the object modified.
+This feature is not shown in our trivial example,
+but its value becomes obvious when nontrivial data structures
+are passed among machines.
+If needed, the user can obtain the
+direction of the XDR operation.
+See the
+.I "XDR Operation Directions"
+section below for details.
+.LP
+Let's look at a slightly more complicated example.
+Assume that a person's gross assets and liabilities
+are to be exchanged among processes.
+Also assume that these values are important enough
+to warrant their own data type:
+.ie t .DS
+.el .DS L
+.ft CW
+struct gnumbers {
+	long g_assets;
+	long g_liabilities;
+};
+.DE
+The corresponding XDR routine describing this structure would be:
+.ie t .DS
+.el .DS L
+.ft CW
+bool_t  		/* \fITRUE is success, FALSE is failure\fP */
+xdr_gnumbers(xdrs, gp)
+	XDR *xdrs;
+	struct gnumbers *gp;
+{
+	if (xdr_long(xdrs, &gp->g_assets) &&
+	    xdr_long(xdrs, &gp->g_liabilities))
+		return(TRUE);
+	return(FALSE);
+}
+.DE
+Note that the parameter
+.I xdrs
+is never inspected or modified;
+it is only passed on to the subcomponent routines.
+It is imperative to inspect the return value of each XDR routine call,
+and to give up immediately and return
+.I FALSE
+if the subroutine fails.
+.LP
+This example also shows that the type
+.I bool_t
+is declared as an integer whose only values are
+.I TRUE
+(1) and
+.I FALSE
+(0).  This document uses the following definitions:
+.ie t .DS
+.el .DS L
+.ft CW
+#define bool_t	int
+#define TRUE	1
+#define FALSE	0
+.DE
+.LP
+Keeping these conventions in mind,
+.I xdr_gnumbers()
+can be rewritten as follows:
+.ie t .DS
+.el .DS L
+.ft CW
+xdr_gnumbers(xdrs, gp)
+	XDR *xdrs;
+	struct gnumbers *gp;
+{
+	return(xdr_long(xdrs, &gp->g_assets) &&
+		xdr_long(xdrs, &gp->g_liabilities));
+}
+.DE
+This document uses both coding styles.
+.NH 1
+\&XDR Library Primitives
+.IX "library primitives for XDR"
+.IX XDR "library primitives"
+.LP
+This section gives a synopsis of each XDR primitive.
+It starts with basic data types and moves on to constructed data types.
+Finally, XDR utilities are discussed.
+The interface to these primitives
+and utilities is defined in the include file
+.I <rpc/xdr.h> ,
+automatically included by
+.I <rpc/rpc.h> .
+.NH 2
+\&Number Filters
+.IX "XDR library" "number filters"
+.LP
+The XDR library provides primitives to translate between numbers
+and their corresponding external representations.
+Primitives cover the set of numbers in:
+.DS
+.ft CW
+[signed, unsigned] * [short, int, long]
+.DE
+.ne 2i
+Specifically, the eight primitives are:
+.DS
+.ft CW
+bool_t xdr_char(xdrs, cp)
+	XDR *xdrs;
+	char *cp;
+.sp .5
+bool_t xdr_u_char(xdrs, ucp)
+	XDR *xdrs;
+	unsigned char *ucp;
+.sp .5
+bool_t xdr_int(xdrs, ip)
+	XDR *xdrs;
+	int *ip;
+.sp .5
+bool_t xdr_u_int(xdrs, up)
+	XDR *xdrs;
+	unsigned *up;
+.sp .5
+bool_t xdr_long(xdrs, lip)
+	XDR *xdrs;
+	long *lip;
+.sp .5
+bool_t xdr_u_long(xdrs, lup)
+	XDR *xdrs;
+	u_long *lup;
+.sp .5
+bool_t xdr_short(xdrs, sip)
+	XDR *xdrs;
+	short *sip;
+.sp .5
+bool_t xdr_u_short(xdrs, sup)
+	XDR *xdrs;
+	u_short *sup;
+.DE
+The first parameter,
+.I xdrs ,
+is an XDR stream handle.
+The second parameter is the address of the number
+that provides data to the stream or receives data from it.
+All routines return
+.I TRUE
+if they complete successfully, and
+.I FALSE
+otherwise.
+.NH 2
+\&Floating Point Filters
+.IX "XDR library" "floating point filters"
+.LP
+The XDR library also provides primitive routines
+for C's floating point types:
+.DS
+.ft CW
+bool_t xdr_float(xdrs, fp)
+	XDR *xdrs;
+	float *fp;
+.sp .5
+bool_t xdr_double(xdrs, dp)
+	XDR *xdrs;
+	double *dp;
+.DE
+The first parameter,
+.I xdrs
+is an XDR stream handle.
+The second parameter is the address
+of the floating point number that provides data to the stream
+or receives data from it.
+Both routines return
+.I TRUE
+if they complete successfully, and
+.I FALSE
+otherwise.
+.LP
+Note: Since the numbers are represented in IEEE floating point,
+routines may fail when decoding a valid IEEE representation
+into a machine-specific representation, or vice-versa.
+.NH 2
+\&Enumeration Filters
+.IX "XDR library" "enumeration filters"
+.LP
+The XDR library provides a primitive for generic enumerations.
+The primitive assumes that a C
+.I enum
+has the same representation inside the machine as a C integer.
+The boolean type is an important instance of the
+.I enum .
+The external representation of a boolean is always
+.I TRUE
+(1) or
+.I FALSE
+(0).
+.DS
+.ft CW
+#define bool_t	int
+#define FALSE	0
+#define TRUE	1
+.sp .5
+#define enum_t int
+.sp .5
+bool_t xdr_enum(xdrs, ep)
+	XDR *xdrs;
+	enum_t *ep;
+.sp .5
+bool_t xdr_bool(xdrs, bp)
+	XDR *xdrs;
+	bool_t *bp;
+.DE
+The second parameters
+.I ep
+and
+.I bp
+are addresses of the associated type that provides data to, or
+receives data from, the stream
+.I xdrs .
+.NH 2
+\&No Data
+.IX "XDR library" "no data"
+.LP
+Occasionally, an XDR routine must be supplied to the RPC system,
+even when no data is passed or required.
+The library provides such a routine:
+.DS
+.ft CW
+bool_t xdr_void();  /* \fIalways returns TRUE\fP */
+.DE
+.NH 2
+\&Constructed Data Type Filters
+.IX "XDR library" "constructed data type filters"
+.LP
+Constructed or compound data type primitives
+require more parameters and perform more complicated functions
+then the primitives discussed above.
+This section includes primitives for
+strings, arrays, unions, and pointers to structures.
+.LP
+Constructed data type primitives may use memory management.
+In many cases, memory is allocated when deserializing data with
+.I XDR_DECODE
+Therefore, the XDR package must provide means to deallocate memory.
+This is done by an XDR operation,
+.I XDR_FREE
+To review, the three XDR directional operations are
+.I XDR_ENCODE ,
+.I XDR_DECODE
+and
+.I XDR_FREE .
+.NH 3
+\&Strings
+.IX "XDR library" "strings"
+.LP
+In C, a string is defined as a sequence of bytes
+terminated by a null byte,
+which is not considered when calculating string length.
+However, when a string is passed or manipulated,
+a pointer to it is employed.
+Therefore, the XDR library defines a string to be a
+.I "char *"
+and not a sequence of characters.
+The external representation of a string is drastically different
+from its internal representation.
+Externally, strings are represented as
+sequences of ASCII characters,
+while internally, they are represented with character pointers.
+Conversion between the two representations
+is accomplished with the routine
+.I xdr_string ():
+.IX xdr_string() "" \fIxdr_string()\fP
+.DS
+.ft CW
+bool_t xdr_string(xdrs, sp, maxlength)
+	XDR *xdrs;
+	char **sp;
+	u_int maxlength;
+.DE
+The first parameter
+.I xdrs
+is the XDR stream handle.
+The second parameter
+.I sp
+is a pointer to a string (type
+.I "char **" .
+The third parameter
+.I maxlength
+specifies the maximum number of bytes allowed during encoding or decoding.
+its value is usually specified by a protocol.  For example, a protocol
+specification may say that a file name may be no longer than 255 characters.
+.LP
+The routine returns
+.I FALSE
+if the number of characters exceeds
+.I maxlength ,
+and
+.I TRUE
+if it doesn't.
+.SH
+Keep
+.I maxlength
+small.  If it is too big you can blow the heap, since
+.I xdr_string()
+will call
+.I malloc()
+for space.
+.LP
+The behavior of
+.I xdr_string()
+.IX xdr_string() "" \fIxdr_string()\fP
+is similar to the behavior of other routines
+discussed in this section.  The direction
+.I XDR_ENCODE
+is easiest to understand.  The parameter
+.I sp
+points to a string of a certain length;
+if the string does not exceed
+.I maxlength ,
+the bytes are serialized.
+.LP
+The effect of deserializing a string is subtle.
+First the length of the incoming string is determined;
+it must not exceed
+.I maxlength .
+Next
+.I sp
+is dereferenced; if the the value is
+.I NULL ,
+then a string of the appropriate length is allocated and
+.I *sp
+is set to this string.
+If the original value of
+.I *sp
+is non-null, then the XDR package assumes
+that a target area has been allocated,
+which can hold strings no longer than
+.I maxlength .
+In either case, the string is decoded into the target area.
+The routine then appends a null character to the string.
+.LP
+In the
+.I XDR_FREE
+operation, the string is obtained by dereferencing
+.I sp .
+If the string is not
+.I NULL ,
+it is freed and
+.I *sp
+is set to
+.I NULL .
+In this operation,
+.I xdr_string()
+ignores the
+.I maxlength
+parameter.
+.NH 3
+\&Byte Arrays
+.IX "XDR library" "byte arrays"
+.LP
+Often variable-length arrays of bytes are preferable to strings.
+Byte arrays differ from strings in the following three ways:
+1) the length of the array (the byte count) is explicitly
+located in an unsigned integer,
+2) the byte sequence is not terminated by a null character, and
+3) the external representation of the bytes is the same as their
+internal representation.
+The primitive
+.I xdr_bytes()
+.IX xdr_bytes() "" \fIxdr_bytes()\fP
+converts between the internal and external
+representations of byte arrays:
+.DS
+.ft CW
+bool_t xdr_bytes(xdrs, bpp, lp, maxlength)
+    XDR *xdrs;
+    char **bpp;
+    u_int *lp;
+    u_int maxlength;
+.DE
+The usage of the first, second and fourth parameters
+are identical to the first, second and third parameters of
+.I xdr_string (),
+respectively.
+The length of the byte area is obtained by dereferencing
+.I lp
+when serializing;
+.I *lp
+is set to the byte length when deserializing.
+.NH 3
+\&Arrays
+.IX "XDR library" "arrays"
+.LP
+The XDR library package provides a primitive
+for handling arrays of arbitrary elements.
+The
+.I xdr_bytes()
+routine treats a subset of generic arrays,
+in which the size of array elements is known to be 1,
+and the external description of each element is built-in.
+The generic array primitive,
+.I xdr_array() ,
+.IX xdr_array() "" \fIxdr_array()\fP
+requires parameters identical to those of
+.I xdr_bytes()
+plus two more:
+the size of array elements,
+and an XDR routine to handle each of the elements.
+This routine is called to encode or decode
+each element of the array.
+.DS
+.ft CW
+bool_t
+xdr_array(xdrs, ap, lp, maxlength, elementsiz, xdr_element)
+    XDR *xdrs;
+    char **ap;
+    u_int *lp;
+    u_int maxlength;
+    u_int elementsiz;
+    bool_t (*xdr_element)();
+.DE
+The parameter
+.I ap
+is the address of the pointer to the array.
+If
+.I *ap
+is
+.I NULL
+when the array is being deserialized,
+XDR allocates an array of the appropriate size and sets
+.I *ap
+to that array.
+The element count of the array is obtained from
+.I *lp
+when the array is serialized;
+.I *lp
+is set to the array length when the array is deserialized.
+The parameter
+.I maxlength
+is the maximum number of elements that the array is allowed to have;
+.I elementsiz
+is the byte size of each element of the array
+(the C function
+.I sizeof()
+can be used to obtain this value).
+The
+.I xdr_element()
+.IX xdr_element() "" \fIxdr_element()\fP
+routine is called to serialize, deserialize, or free
+each element of the array.
+.br
+.LP
+Before defining more constructed data types, it is appropriate to
+present three examples.
+.LP
+.I "Example A:"
+.br
+A user on a networked machine can be identified by
+(a) the machine name, such as
+.I krypton :
+see the
+.I gethostname
+man page; (b) the user's UID: see the
+.I geteuid
+man page; and (c) the group numbers to which the user belongs:
+see the
+.I getgroups
+man page.  A structure with this information and its associated
+XDR routine could be coded like this:
+.ie t .DS
+.el .DS L
+.ft CW
+struct netuser {
+    char    *nu_machinename;
+    int     nu_uid;
+    u_int   nu_glen;
+    int     *nu_gids;
+};
+#define NLEN 255    /* \fImachine names < 256 chars\fP */
+#define NGRPS 20    /* \fIuser can't be in > 20 groups\fP */
+.sp .5
+bool_t
+xdr_netuser(xdrs, nup)
+    XDR *xdrs;
+    struct netuser *nup;
+{
+    return(xdr_string(xdrs, &nup->nu_machinename, NLEN) &&
+        xdr_int(xdrs, &nup->nu_uid) &&
+        xdr_array(xdrs, &nup->nu_gids, &nup->nu_glen,
+        NGRPS, sizeof (int), xdr_int));
+}
+.DE
+.LP
+.I "Example B:"
+.br
+A party of network users could be implemented
+as an array of
+.I netuser
+structure.
+The declaration and its associated XDR routines
+are as follows:
+.ie t .DS
+.el .DS L
+.ft CW
+struct party {
+    u_int p_len;
+    struct netuser *p_nusers;
+};
+#define PLEN 500    /* \fImax number of users in a party\fP */
+.sp .5
+bool_t
+xdr_party(xdrs, pp)
+    XDR *xdrs;
+    struct party *pp;
+{
+    return(xdr_array(xdrs, &pp->p_nusers, &pp->p_len, PLEN,
+        sizeof (struct netuser), xdr_netuser));
+}
+.DE
+.LP
+.I "Example C:"
+.br
+The well-known parameters to
+.I main ,
+.I argc
+and
+.I argv
+can be combined into a structure.
+An array of these structures can make up a history of commands.
+The declarations and XDR routines might look like:
+.ie t .DS
+.el .DS L
+.ft CW
+struct cmd {
+    u_int c_argc;
+    char **c_argv;
+};
+#define ALEN 1000   /* \fIargs cannot be > 1000 chars\fP */
+#define NARGC 100   /* \fIcommands cannot have > 100 args\fP */
+
+struct history {
+    u_int h_len;
+    struct cmd *h_cmds;
+};
+#define NCMDS 75    /* \fIhistory is no more than 75 commands\fP */
+
+bool_t
+xdr_wrap_string(xdrs, sp)
+    XDR *xdrs;
+    char **sp;
+{
+    return(xdr_string(xdrs, sp, ALEN));
+}
+.DE
+.ie t .DS
+.el .DS L
+.ft CW
+bool_t
+xdr_cmd(xdrs, cp)
+    XDR *xdrs;
+    struct cmd *cp;
+{
+    return(xdr_array(xdrs, &cp->c_argv, &cp->c_argc, NARGC,
+        sizeof (char *), xdr_wrap_string));
+}
+.DE
+.ie t .DS
+.el .DS L
+.ft CW
+bool_t
+xdr_history(xdrs, hp)
+    XDR *xdrs;
+    struct history *hp;
+{
+    return(xdr_array(xdrs, &hp->h_cmds, &hp->h_len, NCMDS,
+        sizeof (struct cmd), xdr_cmd));
+}
+.DE
+The most confusing part of this example is that the routine
+.I xdr_wrap_string()
+is needed to package the
+.I xdr_string()
+routine, because the implementation of
+.I xdr_array()
+only passes two parameters to the array element description routine;
+.I xdr_wrap_string()
+supplies the third parameter to
+.I xdr_string ().
+.LP
+By now the recursive nature of the XDR library should be obvious.
+Let's continue with more constructed data types.
+.NH 3
+\&Opaque Data
+.IX "XDR library" "opaque data"
+.LP
+In some protocols, handles are passed from a server to client.
+The client passes the handle back to the server at some later time.
+Handles are never inspected by clients;
+they are obtained and submitted.
+That is to say, handles are opaque.
+The
+.I xdr_opaque()
+.IX xdr_opaque() "" \fIxdr_opaque()\fP
+primitive is used for describing fixed sized, opaque bytes.
+.DS
+.ft CW
+bool_t xdr_opaque(xdrs, p, len)
+    XDR *xdrs;
+    char *p;
+    u_int len;
+.DE
+The parameter
+.I p
+is the location of the bytes;
+.I len
+is the number of bytes in the opaque object.
+By definition, the actual data
+contained in the opaque object are not machine portable.
+.NH 3
+\&Fixed Sized Arrays
+.IX "XDR library" "fixed sized arrays"
+.LP
+The XDR library provides a primitive,
+.I xdr_vector (),
+for fixed-length arrays.
+.ie t .DS
+.el .DS L
+.ft CW
+#define NLEN 255    /* \fImachine names must be < 256 chars\fP */
+#define NGRPS 20    /* \fIuser belongs to exactly 20 groups\fP */
+.sp .5
+struct netuser {
+    char *nu_machinename;
+    int nu_uid;
+    int nu_gids[NGRPS];
+};
+.sp .5
+bool_t
+xdr_netuser(xdrs, nup)
+    XDR *xdrs;
+    struct netuser *nup;
+{
+    int i;
+.sp .5
+    if (!xdr_string(xdrs, &nup->nu_machinename, NLEN))
+        return(FALSE);
+    if (!xdr_int(xdrs, &nup->nu_uid))
+        return(FALSE);
+    if (!xdr_vector(xdrs, nup->nu_gids, NGRPS, sizeof(int),
+        xdr_int)) {
+            return(FALSE);
+    }
+    return(TRUE);
+}
+.DE
+.NH 3
+\&Discriminated Unions
+.IX "XDR library" "discriminated unions"
+.LP
+The XDR library supports discriminated unions.
+A discriminated union is a C union and an
+.I enum_t
+value that selects an \*Qarm\*U of the union.
+.DS
+.ft CW
+struct xdr_discrim {
+    enum_t value;
+    bool_t (*proc)();
+};
+.sp .5
+bool_t xdr_union(xdrs, dscmp, unp, arms, defaultarm)
+    XDR *xdrs;
+    enum_t *dscmp;
+    char *unp;
+    struct xdr_discrim *arms;
+    bool_t (*defaultarm)();  /* \fImay equal NULL\fP */
+.DE
+First the routine translates the discriminant of the union located at
+.I *dscmp .
+The discriminant is always an
+.I enum_t .
+Next the union located at
+.I *unp
+is translated.
+The parameter
+.I arms
+is a pointer to an array of
+.I xdr_discrim
+structures.
+Each structure contains an ordered pair of
+.I [value,proc] .
+If the union's discriminant is equal to the associated
+.I value ,
+then the
+.I proc
+is called to translate the union.
+The end of the
+.I xdr_discrim
+structure array is denoted by a routine of value
+.I NULL
+(0).  If the discriminant is not found in the
+.I arms
+array, then the
+.I defaultarm
+procedure is called if it is non-null;
+otherwise the routine returns
+.I FALSE .
+.LP
+.I "Example D:"
+Suppose the type of a union may be integer,
+character pointer (a string), or a
+.I gnumbers
+structure.
+Also, assume the union and its current type
+are declared in a structure.
+The declaration is:
+.ie t .DS
+.el .DS L
+.ft CW
+enum utype { INTEGER=1, STRING=2, GNUMBERS=3 };
+.sp .5
+struct u_tag {
+    enum utype utype;   /* \fIthe union's discriminant\fP */
+    union {
+        int ival;
+        char *pval;
+        struct gnumbers gn;
+    } uval;
+};
+.DE
+The following constructs and XDR procedure (de)serialize
+the discriminated union:
+.ie t .DS
+.el .DS L
+.ft CW
+struct xdr_discrim u_tag_arms[4] = {
+    { INTEGER, xdr_int },
+    { GNUMBERS, xdr_gnumbers }
+    { STRING, xdr_wrap_string },
+    { __dontcare__, NULL }
+    /* \fIalways terminate arms with a NULL xdr_proc\fP */
+}
+.sp .5
+bool_t
+xdr_u_tag(xdrs, utp)
+    XDR *xdrs;
+    struct u_tag *utp;
+{
+    return(xdr_union(xdrs, &utp->utype, &utp->uval,
+        u_tag_arms, NULL));
+}
+.DE
+The routine
+.I xdr_gnumbers()
+was presented above in
+.I "The XDR Library"
+section.
+.I xdr_wrap_string()
+was presented in example C.
+The default
+.I arm
+parameter to
+.I xdr_union()
+(the last parameter) is
+.I NULL
+in this example.  Therefore the value of the union's discriminant
+may legally take on only values listed in the
+.I u_tag_arms
+array.  This example also demonstrates that
+the elements of the arm's array do not need to be sorted.
+.LP
+It is worth pointing out that the values of the discriminant
+may be sparse, though in this example they are not.
+It is always good
+practice to assign explicitly integer values to each element of the
+discriminant's type.
+This practice both documents the external
+representation of the discriminant and guarantees that different
+C compilers emit identical discriminant values.
+.LP
+Exercise: Implement
+.I xdr_union()
+using the other primitives in this section.
+.NH 3
+\&Pointers
+.IX "XDR library" "pointers"
+.LP
+In C it is often convenient to put pointers
+to another structure within a structure.
+The
+.I xdr_reference()
+.IX xdr_reference() "" \fIxdr_reference()\fP
+primitive makes it easy to serialize, deserialize, and free
+these referenced structures.
+.DS
+.ft CW
+bool_t xdr_reference(xdrs, pp, size, proc)
+    XDR *xdrs;
+    char **pp;
+    u_int ssize;
+    bool_t (*proc)();
+.DE
+.LP
+Parameter
+.I pp
+is the address of
+the pointer to the structure;
+parameter
+.I ssize
+is the size in bytes of the structure (use the C function
+.I sizeof()
+to obtain this value); and
+.I proc
+is the XDR routine that describes the structure.
+When decoding data, storage is allocated if
+.I *pp
+is
+.I NULL .
+.LP
+There is no need for a primitive
+.I xdr_struct()
+to describe structures within structures,
+because pointers are always sufficient.
+.LP
+Exercise: Implement
+.I xdr_reference()
+using
+.I xdr_array ().
+Warning:
+.I xdr_reference()
+and
+.I xdr_array()
+are NOT interchangeable external representations of data.
+.LP
+.I "Example E:"
+Suppose there is a structure containing a person's name
+and a pointer to a
+.I gnumbers
+structure containing the person's gross assets and liabilities.
+The construct is:
+.DS
+.ft CW
+struct pgn {
+    char *name;
+    struct gnumbers *gnp;
+};
+.DE
+The corresponding XDR routine for this structure is:
+.DS
+.ft CW
+bool_t
+xdr_pgn(xdrs, pp)
+    XDR *xdrs;
+    struct pgn *pp;
+{
+    if (xdr_string(xdrs, &pp->name, NLEN) &&
+      xdr_reference(xdrs, &pp->gnp,
+      sizeof(struct gnumbers), xdr_gnumbers))
+        return(TRUE);
+    return(FALSE);
+}
+.DE
+.IX "pointer semantics and XDR"
+.I "Pointer Semantics and XDR"
+.LP
+In many applications, C programmers attach double meaning to
+the values of a pointer.  Typically the value
+.I NULL
+(or zero) means data is not needed,
+yet some application-specific interpretation applies.
+In essence, the C programmer is encoding
+a discriminated union efficiently
+by overloading the interpretation of the value of a pointer.
+For instance, in example E a
+.I NULL
+pointer value for
+.I gnp
+could indicate that
+the person's assets and liabilities are unknown.
+That is, the pointer value encodes two things:
+whether or not the data is known;
+and if it is known, where it is located in memory.
+Linked lists are an extreme example of the use
+of application-specific pointer interpretation.
+.LP
+The primitive
+.I xdr_reference()
+.IX xdr_reference() "" \fIxdr_reference()\fP
+cannot and does not attach any special
+meaning to a null-value pointer during serialization.
+That is, passing an address of a pointer whose value is
+.I NULL
+to
+.I xdr_reference()
+when serialing data will most likely cause a memory fault and, on the UNIX
+system, a core dump.
+.LP
+.I xdr_pointer()
+correctly handles
+.I NULL
+pointers.  For more information about its use, see
+the
+.I "Linked Lists"
+topics below.
+.LP
+.I Exercise:
+After reading the section on
+.I "Linked Lists" ,
+return here and extend example E so that
+it can correctly deal with
+.I NULL
+pointer values.
+.LP
+.I Exercise:
+Using the
+.I xdr_union (),
+.I xdr_reference()
+and
+.I xdr_void()
+primitives, implement a generic pointer handling primitive
+that implicitly deals with
+.I NULL
+pointers.  That is, implement
+.I xdr_pointer ().
+.NH 2
+\&Non-filter Primitives
+.IX "XDR" "non-filter primitives"
+.LP
+XDR streams can be manipulated with
+the primitives discussed in this section.
+.DS
+.ft CW
+u_int xdr_getpos(xdrs)
+    XDR *xdrs;
+.sp .5
+bool_t xdr_setpos(xdrs, pos)
+    XDR *xdrs;
+    u_int pos;
+.sp .5
+xdr_destroy(xdrs)
+    XDR *xdrs;
+.DE
+The routine
+.I xdr_getpos()
+.IX xdr_getpos() "" \fIxdr_getpos()\fP
+returns an unsigned integer
+that describes the current position in the data stream.
+Warning: In some XDR streams, the returned value of
+.I xdr_getpos()
+is meaningless;
+the routine returns a \-1 in this case
+(though \-1 should be a legitimate value).
+.LP
+The routine
+.I xdr_setpos()
+.IX xdr_setpos() "" \fIxdr_setpos()\fP
+sets a stream position to
+.I pos .
+Warning: In some XDR streams, setting a position is impossible;
+in such cases,
+.I xdr_setpos()
+will return
+.I FALSE .
+This routine will also fail if the requested position is out-of-bounds.
+The definition of bounds varies from stream to stream.
+.LP
+The
+.I xdr_destroy()
+.IX xdr_destroy() "" \fIxdr_destroy()\fP
+primitive destroys the XDR stream.
+Usage of the stream
+after calling this routine is undefined.
+.NH 2
+\&XDR Operation Directions
+.IX XDR "operation directions"
+.IX "direction of XDR operations"
+.LP
+At times you may wish to optimize XDR routines by taking
+advantage of the direction of the operation \(em
+.I XDR_ENCODE
+.I XDR_DECODE
+or
+.I XDR_FREE
+The value
+.I xdrs->x_op
+always contains the direction of the XDR operation.
+Programmers are not encouraged to take advantage of this information.
+Therefore, no example is presented here.  However, an example in the
+.I "Linked Lists"
+topic below, demonstrates the usefulness of the
+.I xdrs->x_op
+field.
+.NH 2
+\&XDR Stream Access
+.IX "XDR" "stream access"
+.LP
+An XDR stream is obtained by calling the appropriate creation routine.
+These creation routines take arguments that are tailored to the
+specific properties of the stream.
+.LP
+Streams currently exist for (de)serialization of data to or from
+standard I/O
+.I FILE
+streams, TCP/IP connections and UNIX files, and memory.
+.NH 3
+\&Standard I/O Streams
+.IX "XDR" "standard I/O streams"
+.LP
+XDR streams can be interfaced to standard I/O using the
+.I xdrstdio_create()
+.IX xdrstdio_create() "" \fIxdrstdio_create()\fP
+routine as follows:
+.DS
+.ft CW
+#include <stdio.h>
+#include <rpc/rpc.h>    /* \fIxdr streams part of rpc\fP */
+.sp .5
+void
+xdrstdio_create(xdrs, fp, x_op)
+    XDR *xdrs;
+    FILE *fp;
+    enum xdr_op x_op;
+.DE
+The routine
+.I xdrstdio_create()
+initializes an XDR stream pointed to by
+.I xdrs .
+The XDR stream interfaces to the standard I/O library.
+Parameter
+.I fp
+is an open file, and
+.I x_op
+is an XDR direction.
+.NH 3
+\&Memory Streams
+.IX "XDR" "memory streams"
+.LP
+Memory streams allow the streaming of data into or out of
+a specified area of memory:
+.DS
+.ft CW
+#include <rpc/rpc.h>
+.sp .5
+void
+xdrmem_create(xdrs, addr, len, x_op)
+    XDR *xdrs;
+    char *addr;
+    u_int len;
+    enum xdr_op x_op;
+.DE
+The routine
+.I xdrmem_create()
+.IX xdrmem_create() "" \fIxdrmem_create()\fP
+initializes an XDR stream in local memory.
+The memory is pointed to by parameter
+.I addr ;
+parameter
+.I len
+is the length in bytes of the memory.
+The parameters
+.I xdrs
+and
+.I x_op
+are identical to the corresponding parameters of
+.I xdrstdio_create ().
+Currently, the UDP/IP implementation of RPC uses
+.I xdrmem_create ().
+Complete call or result messages are built in memory before calling the
+.I sendto()
+system routine.
+.NH 3
+\&Record (TCP/IP) Streams
+.IX "XDR" "record (TCP/IP) streams"
+.LP
+A record stream is an XDR stream built on top of
+a record marking standard that is built on top of the
+UNIX file or 4.2 BSD connection interface.
+.DS
+.ft CW
+#include <rpc/rpc.h>    /* \fIxdr streams part of rpc\fP */
+.sp .5
+xdrrec_create(xdrs,
+  sendsize, recvsize, iohandle, readproc, writeproc)
+    XDR *xdrs;
+    u_int sendsize, recvsize;
+    char *iohandle;
+    int (*readproc)(), (*writeproc)();
+.DE
+The routine
+.I xdrrec_create()
+provides an XDR stream interface that allows for a bidirectional,
+arbitrarily long sequence of records.
+The contents of the records are meant to be data in XDR form.
+The stream's primary use is for interfacing RPC to TCP connections.
+However, it can be used to stream data into or out of normal
+UNIX files.
+.LP
+The parameter
+.I xdrs
+is similar to the corresponding parameter described above.
+The stream does its own data buffering similar to that of standard I/O.
+The parameters
+.I sendsize
+and
+.I recvsize
+determine the size in bytes of the output and input buffers, respectively;
+if their values are zero (0), then predetermined defaults are used.
+When a buffer needs to be filled or flushed, the routine
+.I readproc()
+or
+.I writeproc()
+is called, respectively.
+The usage and behavior of these
+routines are similar to the UNIX system calls
+.I read()
+and
+.I write ().
+However,
+the first parameter to each of these routines is the opaque parameter
+.I iohandle .
+The other two parameters
+.I buf ""
+and
+.I nbytes )
+and the results
+(byte count) are identical to the system routines.
+If
+.I xxx
+is
+.I readproc()
+or
+.I writeproc (),
+then it has the following form:
+.DS
+.ft CW
+.ft I
+/*
+ * returns the actual number of bytes transferred.
+ * -1 is an error
+ */
+.ft CW
+int
+xxx(iohandle, buf, len)
+    char *iohandle;
+    char *buf;
+    int nbytes;
+.DE
+The XDR stream provides means for delimiting records in the byte stream.
+The implementation details of delimiting records in a stream are
+discussed in the
+.I "Advanced Topics"
+topic below.
+The primitives that are specific to record streams are as follows:
+.DS
+.ft CW
+bool_t
+xdrrec_endofrecord(xdrs, flushnow)
+    XDR *xdrs;
+    bool_t flushnow;
+.sp .5
+bool_t
+xdrrec_skiprecord(xdrs)
+    XDR *xdrs;
+.sp .5
+bool_t
+xdrrec_eof(xdrs)
+    XDR *xdrs;
+.DE
+The routine
+.I xdrrec_endofrecord()
+.IX xdrrec_endofrecord() "" \fIxdrrec_endofrecord()\fP
+causes the current outgoing data to be marked as a record.
+If the parameter
+.I flushnow
+is
+.I TRUE ,
+then the stream's
+.I writeproc
+will be called; otherwise,
+.I writeproc
+will be called when the output buffer has been filled.
+.LP
+The routine
+.I xdrrec_skiprecord()
+.IX xdrrec_skiprecord() "" \fIxdrrec_skiprecord()\fP
+causes an input stream's position to be moved past
+the current record boundary and onto the
+beginning of the next record in the stream.
+.LP
+If there is no more data in the stream's input buffer,
+then the routine
+.I xdrrec_eof()
+.IX xdrrec_eof() "" \fIxdrrec_eof()\fP
+returns
+.I TRUE .
+That is not to say that there is no more data
+in the underlying file descriptor.
+.NH 2
+\&XDR Stream Implementation
+.IX "XDR" "stream implementation"
+.IX "stream implementation in XDR"
+.LP
+This section provides the abstract data types needed
+to implement new instances of XDR streams.
+.NH 3
+\&The XDR Object
+.IX "XDR" "object"
+.LP
+The following structure defines the interface to an XDR stream:
+.ie t .DS
+.el .DS L
+.ft CW
+enum xdr_op { XDR_ENCODE=0, XDR_DECODE=1, XDR_FREE=2 };
+.sp .5
+typedef struct {
+    enum xdr_op x_op;            /* \fIoperation; fast added param\fP */
+    struct xdr_ops {
+        bool_t  (*x_getlong)();  /* \fIget long from stream\fP */
+        bool_t  (*x_putlong)();  /* \fIput long to stream\fP */
+        bool_t  (*x_getbytes)(); /* \fIget bytes from stream\fP */
+        bool_t  (*x_putbytes)(); /* \fIput bytes to stream\fP */
+        u_int   (*x_getpostn)(); /* \fIreturn stream offset\fP */
+        bool_t  (*x_setpostn)(); /* \fIreposition offset\fP */
+        caddr_t (*x_inline)();   /* \fIptr to buffered data\fP */
+        VOID    (*x_destroy)();  /* \fIfree private area\fP */
+    } *x_ops;
+    caddr_t     x_public;        /* \fIusers' data\fP */
+    caddr_t     x_private;       /* \fIpointer to private data\fP */
+    caddr_t     x_base;          /* \fIprivate for position info\fP */
+    int         x_handy;         /* \fIextra private word\fP */
+} XDR;
+.DE
+The
+.I x_op
+field is the current operation being performed on the stream.
+This field is important to the XDR primitives,
+but should not affect a stream's implementation.
+That is, a stream's implementation should not depend
+on this value.
+The fields
+.I x_private ,
+.I x_base ,
+and
+.I x_handy
+are private to the particular
+stream's implementation.
+The field
+.I x_public
+is for the XDR client and should never be used by
+the XDR stream implementations or the XDR primitives.
+.I x_getpostn() ,
+.I x_setpostn()
+and
+.I x_destroy()
+are macros for accessing operations.  The operation
+.I x_inline()
+takes two parameters:
+an XDR *, and an unsigned integer, which is a byte count.
+The routine returns a pointer to a piece of
+the stream's internal buffer.
+The caller can then use the buffer segment for any purpose.
+From the stream's point of view, the bytes in the
+buffer segment have been consumed or put.
+The routine may return
+.I NULL
+if it cannot return a buffer segment of the requested size.
+(The
+.I x_inline()
+routine is for cycle squeezers.
+Use of the resulting buffer is not data-portable.
+Users are encouraged not to use this feature.)
+.LP
+The operations
+.I x_getbytes()
+and
+.I x_putbytes()
+blindly get and put sequences of bytes
+from or to the underlying stream;
+they return
+.I TRUE
+if they are successful, and
+.I FALSE
+otherwise.  The routines have identical parameters (replace
+.I xxx ):
+.DS
+.ft CW
+bool_t
+xxxbytes(xdrs, buf, bytecount)
+	XDR *xdrs;
+	char *buf;
+	u_int bytecount;
+.DE
+The operations
+.I x_getlong()
+and
+.I x_putlong()
+receive and put
+long numbers from and to the data stream.
+It is the responsibility of these routines
+to translate the numbers between the machine representation
+and the (standard) external representation.
+The UNIX primitives
+.I htonl()
+and
+.I ntohl()
+can be helpful in accomplishing this.
+The higher-level XDR implementation assumes that
+signed and unsigned long integers contain the same number of bits,
+and that nonnegative integers
+have the same bit representations as unsigned integers.
+The routines return
+.I TRUE
+if they succeed, and
+.I FALSE
+otherwise.  They have identical parameters:
+.DS
+.ft CW
+bool_t
+xxxlong(xdrs, lp)
+	XDR *xdrs;
+	long *lp;
+.DE
+Implementors of new XDR streams must make an XDR structure
+(with new operation routines) available to clients,
+using some kind of create routine.
+.NH 1
+\&Advanced Topics
+.IX XDR "advanced topics"
+.LP
+This section describes techniques for passing data structures that
+are not covered in the preceding sections.  Such structures include
+linked lists (of arbitrary lengths).  Unlike the simpler examples
+covered in the earlier sections, the following examples are written
+using both the XDR C library routines and the XDR data description
+language.
+The
+.I "External Data Representation Standard: Protocol Specification"
+describes this
+language in complete detail.
+.NH 2
+\&Linked Lists
+.IX XDR "linked lists"
+.LP
+The last example in the
+.I Pointers
+topic earlier in this chapter
+presented a C data structure and its associated XDR
+routines for an individual's gross assets and liabilities.
+The example is duplicated below:
+.ie t .DS
+.el .DS L
+.ft CW
+struct gnumbers {
+	long g_assets;
+	long g_liabilities;
+};
+.sp .5
+bool_t
+xdr_gnumbers(xdrs, gp)
+	XDR *xdrs;
+	struct gnumbers *gp;
+{
+	if (xdr_long(xdrs, &(gp->g_assets)))
+		return(xdr_long(xdrs, &(gp->g_liabilities)));
+	return(FALSE);
+}
+.DE
+.LP
+Now assume that we wish to implement a linked list of such information.
+A data structure could be constructed as follows:
+.ie t .DS
+.el .DS L
+.ft CW
+struct gnumbers_node {
+	struct gnumbers gn_numbers;
+	struct gnumbers_node *gn_next;
+};
+.sp .5
+typedef struct gnumbers_node *gnumbers_list;
+.DE
+.LP
+The head of the linked list can be thought of as the data object;
+that is, the head is not merely a convenient shorthand for a
+structure.  Similarly the
+.I gn_next
+field is used to indicate whether or not the object has terminated.
+Unfortunately, if the object continues, the
+.I gn_next
+field is also the address of where it continues. The link addresses
+carry no useful information when the object is serialized.
+.LP
+The XDR data description of this linked list is described by the
+recursive declaration of
+.I gnumbers_list :
+.ie t .DS
+.el .DS L
+.ft CW
+struct gnumbers {
+	int g_assets;
+	int g_liabilities;
+};
+.sp .5
+struct gnumbers_node {
+	gnumbers gn_numbers;
+	gnumbers_node *gn_next;
+};
+.DE
+.LP
+In this description, the boolean indicates whether there is more data
+following it. If the boolean is
+.I FALSE ,
+then it is the last data field of the structure. If it is
+.I TRUE ,
+then it is followed by a gnumbers structure and (recursively) by a
+.I gnumbers_list .
+Note that the C declaration has no boolean explicitly declared in it
+(though the
+.I gn_next
+field implicitly carries the information), while the XDR data
+description has no pointer explicitly declared in it.
+.LP
+Hints for writing the XDR routines for a
+.I gnumbers_list
+follow easily from the XDR description above. Note how the primitive
+.I xdr_pointer()
+is used to implement the XDR union above.
+.ie t .DS
+.el .DS L
+.ft CW
+bool_t
+xdr_gnumbers_node(xdrs, gn)
+	XDR *xdrs;
+	gnumbers_node *gn;
+{
+	return(xdr_gnumbers(xdrs, &gn->gn_numbers) &&
+		xdr_gnumbers_list(xdrs, &gp->gn_next));
+}
+.sp .5
+bool_t
+xdr_gnumbers_list(xdrs, gnp)
+	XDR *xdrs;
+	gnumbers_list *gnp;
+{
+	return(xdr_pointer(xdrs, gnp,
+		sizeof(struct gnumbers_node),
+		xdr_gnumbers_node));
+}
+.DE
+.LP
+The unfortunate side effect of XDR'ing a list with these routines
+is that the C stack grows linearly with respect to the number of
+node in the list.  This is due to the recursion. The following
+routine collapses the above two mutually recursive into a single,
+non-recursive one.
+.ie t .DS
+.el .DS L
+.ft CW
+bool_t
+xdr_gnumbers_list(xdrs, gnp)
+	XDR *xdrs;
+	gnumbers_list *gnp;
+{
+	bool_t more_data;
+	gnumbers_list *nextp;
+.sp .5
+	for (;;) {
+		more_data = (*gnp != NULL);
+		if (!xdr_bool(xdrs, &more_data)) {
+			return(FALSE);
+		}
+		if (! more_data) {
+			break;
+		}
+		if (xdrs->x_op == XDR_FREE) {
+			nextp = &(*gnp)->gn_next;
+		}
+		if (!xdr_reference(xdrs, gnp,
+			sizeof(struct gnumbers_node), xdr_gnumbers)) {
+
+		return(FALSE);
+		}
+		gnp = (xdrs->x_op == XDR_FREE) ?
+			nextp : &(*gnp)->gn_next;
+	}
+	*gnp = NULL;
+	return(TRUE);
+}
+.DE
+.LP
+The first task is to find out whether there is more data or not,
+so that this boolean information can be serialized. Notice that
+this statement is unnecessary in the
+.I XDR_DECODE
+case, since the value of more_data is not known until we
+deserialize it in the next statement.
+.LP
+The next statement XDR's the more_data field of the XDR union.
+Then if there is truly no more data, we set this last pointer to
+.I NULL
+to indicate the end of the list, and return
+.I TRUE
+because we are done. Note that setting the pointer to
+.I NULL
+is only important in the
+.I XDR_DECODE
+case, since it is already
+.I NULL
+in the
+.I XDR_ENCODE
+and
+XDR_FREE
+cases.
+.LP
+Next, if the direction is
+.I XDR_FREE ,
+the value of
+.I nextp
+is set to indicate the location of the next pointer in the list.
+We do this now because we need to dereference gnp to find the
+location of the next item in the list, and after the next
+statement the storage pointed to by
+.I gnp
+will be freed up and no be longer valid.  We can't do this for all
+directions though, because in the
+.I XDR_DECODE
+direction the value of
+.I gnp
+won't be set until the next statement.
+.LP
+Next, we XDR the data in the node using the primitive
+.I xdr_reference ().
+.I xdr_reference()
+is like
+.I xdr_pointer()
+which we used before, but it does not
+send over the boolean indicating whether there is more data.
+We use it instead of
+.I xdr_pointer()
+because we have already XDR'd this information ourselves. Notice
+that the xdr routine passed is not the same type as an element
+in the list. The routine passed is
+.I xdr_gnumbers (),
+for XDR'ing gnumbers, but each element in the list is actually of
+type
+.I gnumbers_node .
+We don't pass
+.I xdr_gnumbers_node()
+because it is recursive, and instead use
+.I xdr_gnumbers()
+which XDR's all of the non-recursive part.  Note that this trick
+will work only if the
+.I gn_numbers
+field is the first item in each element, so that their addresses
+are identical when passed to
+.I xdr_reference ().
+.LP
+Finally, we update
+.I gnp
+to point to the next item in the list. If the direction is
+.I XDR_FREE ,
+we set it to the previously saved value, otherwise we can
+dereference
+.I gnp
+to get the proper value.  Though harder to understand than the
+recursive version, this non-recursive routine is far less likely
+to blow the C stack.  It will also run more efficiently since
+a lot of procedure call overhead has been removed. Most lists
+are small though (in the hundreds of items or less) and the
+recursive version should be sufficient for them.
+.EQ
+delim off
+.EN
diff --git a/share/doc/psd/25.xdrrfc/Makefile b/share/doc/psd/25.xdrrfc/Makefile
index 105135e..7045d45 100644
--- a/share/doc/psd/25.xdrrfc/Makefile
+++ b/share/doc/psd/25.xdrrfc/Makefile
@@ -4,6 +4,5 @@ VOLUME=		psd/25.xdrrfc
 SRCS=		stubs xdr.rfc.ms
 MACROS=		-ms
 USE_TBL=
-SRCDIR=		${.CURDIR}/../../../../lib/libc/rpc/PSD.doc
 
 .include <bsd.doc.mk>
diff --git a/share/doc/psd/25.xdrrfc/stubs b/share/doc/psd/25.xdrrfc/stubs
new file mode 100644
index 0000000..78b0a2c
--- /dev/null
+++ b/share/doc/psd/25.xdrrfc/stubs
@@ -0,0 +1,3 @@
+.\" $FreeBSD$
+.\"
+.if t .ftr L CR
diff --git a/share/doc/psd/25.xdrrfc/xdr.rfc.ms b/share/doc/psd/25.xdrrfc/xdr.rfc.ms
new file mode 100644
index 0000000..480a339
--- /dev/null
+++ b/share/doc/psd/25.xdrrfc/xdr.rfc.ms
@@ -0,0 +1,1060 @@
+.\"
+.\"  Must use -- tbl -- with this one
+.\"
+.\" @(#)xdr.rfc.ms	2.2 88/08/05 4.0 RPCSRC
+.\" $FreeBSD$
+.\"
+.de BT
+.if \\n%=1 .tl ''- % -''
+..
+.ND
+.\" prevent excess underlining in nroff
+.if n .fp 2 R
+.OH 'External Data Representation Standard''Page %'
+.EH 'Page %''External Data Representation Standard'
+.if \n%=1 .bp
+.SH
+\&External Data Representation Standard: Protocol Specification
+.IX "External Data Representation"
+.IX XDR RFC
+.IX XDR "protocol specification"
+.LP
+.NH 0
+\&Status of this Standard
+.nr OF 1
+.IX XDR "RFC status"
+.LP
+Note: This chapter specifies a protocol that Sun Microsystems, Inc., and 
+others are using.  It has been designated RFC1014 by the ARPA Network
+Information Center.
+.NH 1
+Introduction
+\&
+.LP
+XDR is a standard for the description and encoding of data.  It is
+useful for transferring data between different computer
+architectures, and has been used to communicate data between such
+diverse machines as the Sun Workstation, VAX, IBM-PC, and Cray.
+XDR fits into the ISO presentation layer, and is roughly analogous in
+purpose to X.409, ISO Abstract Syntax Notation.  The major difference
+between these two is that XDR uses implicit typing, while X.409 uses
+explicit typing.
+.LP
+XDR uses a language to describe data formats.  The language can only
+be used only to describe data; it is not a programming language.
+This language allows one to describe intricate data formats in a
+concise manner. The alternative of using graphical representations
+(itself an informal language) quickly becomes incomprehensible when
+faced with complexity.  The XDR language itself is similar to the C
+language [1], just as Courier [4] is similar to Mesa. Protocols such
+as Sun RPC (Remote Procedure Call) and the NFS (Network File System)
+use XDR to describe the format of their data.
+.LP
+The XDR standard makes the following assumption: that bytes (or
+octets) are portable, where a byte is defined to be 8 bits of data.
+A given hardware device should encode the bytes onto the various
+media in such a way that other hardware devices may decode the bytes
+without loss of meaning.  For example, the Ethernet standard
+suggests that bytes be encoded in "little-endian" style [2], or least
+significant bit first.
+.NH 2
+\&Basic Block Size
+.IX XDR "basic block size"
+.IX XDR "block size"
+.LP
+The representation of all items requires a multiple of four bytes (or
+32 bits) of data.  The bytes are numbered 0 through n-1.  The bytes
+are read or written to some byte stream such that byte m always
+precedes byte m+1.  If the n bytes needed to contain the data are not
+a multiple of four, then the n bytes are followed by enough (0 to 3)
+residual zero bytes, r, to make the total byte count a multiple of 4.
+.LP
+We include the familiar graphic box notation for illustration and
+comparison.  In most illustrations, each box (delimited by a plus
+sign at the 4 corners and vertical bars and dashes) depicts a byte.
+Ellipses (...) between boxes show zero or more additional bytes where
+required.
+.ie t .DS
+.el .DS L
+\fIA Block\fP
+
+\f(CW+--------+--------+...+--------+--------+...+--------+
+| byte 0 | byte 1 |...|byte n-1|    0   |...|    0   |
++--------+--------+...+--------+--------+...+--------+
+|<-----------n bytes---------->|<------r bytes------>|
+|<-----------n+r (where (n+r) mod 4 = 0)>----------->|\fP
+
+.DE
+.NH 1
+\&XDR Data Types
+.IX XDR "data types"
+.IX "XDR data types"
+.LP
+Each of the sections that follow describes a data type defined in the
+XDR standard, shows how it is declared in the language, and includes
+a graphic illustration of its encoding.
+.LP
+For each data type in the language we show a general paradigm
+declaration.  Note that angle brackets (< and >) denote
+variable length sequences of data and square brackets ([ and ]) denote
+fixed-length sequences of data.  "n", "m" and "r" denote integers.
+For the full language specification and more formal definitions of
+terms such as "identifier" and "declaration", refer to
+.I "The XDR Language Specification" ,
+below.
+.LP
+For some data types, more specific examples are included.  
+A more extensive example of a data description is in
+.I "An Example of an XDR Data Description"
+below.
+.NH 2
+\&Integer
+.IX XDR integer
+.LP
+An XDR signed integer is a 32-bit datum that encodes an integer in
+the range [-2147483648,2147483647].  The integer is represented in
+two's complement notation.  The most and least significant bytes are
+0 and 3, respectively.  Integers are declared as follows:
+.ie t .DS
+.el .DS L
+\fIInteger\fP
+
+\f(CW(MSB)                   (LSB)
++-------+-------+-------+-------+
+|byte 0 |byte 1 |byte 2 |byte 3 |
++-------+-------+-------+-------+
+<------------32 bits------------>\fP
+.DE
+.NH 2
+\&Unsigned Integer
+.IX XDR "unsigned integer"
+.IX XDR "integer, unsigned"
+.LP
+An XDR unsigned integer is a 32-bit datum that encodes a nonnegative
+integer in the range [0,4294967295].  It is represented by an
+unsigned binary number whose most and least significant bytes are 0
+and 3, respectively.  An unsigned integer is declared as follows:
+.ie t .DS
+.el .DS L
+\fIUnsigned Integer\fP
+
+\f(CW(MSB)                   (LSB)
++-------+-------+-------+-------+
+|byte 0 |byte 1 |byte 2 |byte 3 |
++-------+-------+-------+-------+
+<------------32 bits------------>\fP
+.DE
+.NH 2
+\&Enumeration
+.IX XDR enumeration
+.LP
+Enumerations have the same representation as signed integers.
+Enumerations are handy for describing subsets of the integers.
+Enumerated data is declared as follows:
+.ft CW
+.DS
+enum { name-identifier = constant, ... } identifier;
+.DE
+For example, the three colors red, yellow, and blue could be
+described by an enumerated type:
+.DS
+.ft CW
+enum { RED = 2, YELLOW = 3, BLUE = 5 } colors;
+.DE
+It is an error to encode as an enum any other integer than those that
+have been given assignments in the enum declaration.
+.NH 2
+\&Boolean
+.IX XDR boolean
+.LP
+Booleans are important enough and occur frequently enough to warrant
+their own explicit type in the standard.  Booleans are declared as
+follows:
+.DS
+.ft CW
+bool identifier;
+.DE
+This is equivalent to:
+.DS
+.ft CW
+enum { FALSE = 0, TRUE = 1 } identifier;
+.DE
+.NH 2
+\&Hyper Integer and Unsigned Hyper Integer
+.IX XDR "hyper integer"
+.IX XDR "integer, hyper"
+.LP
+The standard also defines 64-bit (8-byte) numbers called hyper
+integer and unsigned hyper integer.  Their representations are the
+obvious extensions of integer and unsigned integer defined above.
+They are represented in two's complement notation.  The most and
+least significant bytes are 0 and 7, respectively.  Their
+declarations:
+.ie t .DS
+.el .DS L
+\fIHyper Integer\fP
+\fIUnsigned Hyper Integer\fP
+
+\f(CW(MSB)                                                   (LSB)
++-------+-------+-------+-------+-------+-------+-------+-------+
+|byte 0 |byte 1 |byte 2 |byte 3 |byte 4 |byte 5 |byte 6 |byte 7 |
++-------+-------+-------+-------+-------+-------+-------+-------+
+<----------------------------64 bits---------------------------->\fP
+.DE
+.NH 2
+\&Floating-point
+.IX XDR "integer, floating point"
+.IX XDR "floating-point integer"
+.LP
+The standard defines the floating-point data type "float" (32 bits or
+4 bytes).  The encoding used is the IEEE standard for normalized
+single-precision floating-point numbers [3].  The following three
+fields describe the single-precision floating-point number:
+.RS
+.IP \fBS\fP:
+The sign of the number.  Values 0 and  1 represent  positive and
+negative, respectively.  One bit.
+.IP \fBE\fP:
+The exponent of the number, base 2.  8  bits are devoted to this
+field.  The exponent is biased by 127.
+.IP \fBF\fP:
+The fractional part of the number's mantissa,  base 2.   23 bits
+are devoted to this field.
+.RE
+.LP
+Therefore, the floating-point number is described by:
+.DS
+(-1)**S * 2**(E-Bias) * 1.F
+.DE
+It is declared as follows:
+.ie t .DS
+.el .DS L
+\fISingle-Precision Floating-Point\fP
+
+\f(CW+-------+-------+-------+-------+
+|byte 0 |byte 1 |byte 2 |byte 3 |
+S|   E   |           F          |
++-------+-------+-------+-------+
+1|<- 8 ->|<-------23 bits------>|
+<------------32 bits------------>\fP
+.DE
+Just as the most and least significant bytes of a number are 0 and 3,
+the most and least significant bits of a single-precision floating-
+point number are 0 and 31.  The beginning bit (and most significant
+bit) offsets of S, E, and F are 0, 1, and 9, respectively.  Note that
+these numbers refer to the mathematical positions of the bits, and
+NOT to their actual physical locations (which vary from medium to
+medium).
+.LP
+The IEEE specifications should be consulted concerning the encoding
+for signed zero, signed infinity (overflow), and denormalized numbers
+(underflow) [3].  According to IEEE specifications, the "NaN" (not a
+number) is system dependent and should not be used externally.
+.NH 2
+\&Double-precision Floating-point
+.IX XDR "integer, double-precision floating point"
+.IX XDR "double-precision floating-point integer"
+.LP
+The standard defines the encoding for the double-precision floating-
+point data type "double" (64 bits or 8 bytes).  The encoding used is
+the IEEE standard for normalized double-precision floating-point
+numbers [3].  The standard encodes the following three fields, which
+describe the double-precision floating-point number:
+.RS
+.IP \fBS\fP:
+The sign of the number.  Values  0 and 1  represent positive and
+negative, respectively.  One bit.
+.IP \fBE\fP:
+The exponent of the number, base 2.  11 bits are devoted to this
+field.  The exponent is biased by 1023.
+.IP \fBF\fP:
+The fractional part of the number's  mantissa, base 2.   52 bits
+are devoted to this field.
+.RE
+.LP
+Therefore, the floating-point number is described by:
+.DS
+(-1)**S * 2**(E-Bias) * 1.F
+.DE
+It is declared as follows:
+.ie t .DS
+.el .DS L
+\fIDouble-Precision Floating-Point\fP
+
+\f(CW+------+------+------+------+------+------+------+------+
+|byte 0|byte 1|byte 2|byte 3|byte 4|byte 5|byte 6|byte 7|
+S|    E   |                    F                        |
++------+------+------+------+------+------+------+------+
+1|<--11-->|<-----------------52 bits------------------->|
+<-----------------------64 bits------------------------->\fP
+.DE
+Just as the most and least significant bytes of a number are 0 and 3,
+the most and least significant bits of a double-precision floating-
+point number are 0 and 63.  The beginning bit (and most significant
+bit) offsets of S, E , and F are 0, 1, and 12, respectively.  Note
+that these numbers refer to the mathematical positions of the bits,
+and NOT to their actual physical locations (which vary from medium to
+medium).
+.LP
+The IEEE specifications should be consulted concerning the encoding
+for signed zero, signed infinity (overflow), and denormalized numbers
+(underflow) [3].  According to IEEE specifications, the "NaN" (not a
+number) is system dependent and should not be used externally.
+.NH 2
+\&Fixed-length Opaque Data
+.IX XDR "fixed-length opaque data"
+.IX XDR "opaque data, fixed length"
+.LP
+At times, fixed-length uninterpreted data needs to be passed among
+machines.  This data is called "opaque" and is declared as follows:
+.DS
+.ft CW
+opaque identifier[n];
+.DE
+where the constant n is the (static) number of bytes necessary to
+contain the opaque data.  If n is not a multiple of four, then the n
+bytes are followed by enough (0 to 3) residual zero bytes, r, to make
+the total byte count of the opaque object a multiple of four.
+.ie t .DS
+.el .DS L
+\fIFixed-Length Opaque\fP
+
+\f(CW0        1     ...
++--------+--------+...+--------+--------+...+--------+
+| byte 0 | byte 1 |...|byte n-1|    0   |...|    0   |
++--------+--------+...+--------+--------+...+--------+
+|<-----------n bytes---------->|<------r bytes------>|
+|<-----------n+r (where (n+r) mod 4 = 0)------------>|\fP
+.DE
+.NH 2
+\&Variable-length Opaque Data
+.IX XDR "variable-length opaque data"
+.IX XDR "opaque data, variable length"
+.LP
+The standard also provides for variable-length (counted) opaque data,
+defined as a sequence of n (numbered 0 through n-1) arbitrary bytes
+to be the number n encoded as an unsigned integer (as described
+below), and followed by the n bytes of the sequence.
+.LP
+Byte m of the sequence always precedes byte m+1 of the sequence, and
+byte 0 of the sequence always follows the sequence's length (count).
+enough (0 to 3) residual zero bytes, r, to make the total byte count
+a multiple of four.  Variable-length opaque data is declared in the
+following way:
+.DS
+.ft CW
+opaque identifier<m>;
+.DE
+or
+.DS
+.ft CW
+opaque identifier<>;
+.DE
+The constant m denotes an upper bound of the number of bytes that the
+sequence may contain.  If m is not specified, as in the second
+declaration, it is assumed to be (2**32) - 1, the maximum length.
+The constant m would normally be found in a protocol specification.
+For example, a filing protocol may state that the maximum data
+transfer size is 8192 bytes, as follows:
+.DS
+.ft CW
+opaque filedata<8192>;
+.DE
+This can be illustrated as follows:
+.ie t .DS
+.el .DS L
+\fIVariable-Length Opaque\fP
+
+\f(CW0     1     2     3     4     5   ...
++-----+-----+-----+-----+-----+-----+...+-----+-----+...+-----+
+|        length n       |byte0|byte1|...| n-1 |  0  |...|  0  |
++-----+-----+-----+-----+-----+-----+...+-----+-----+...+-----+
+|<-------4 bytes------->|<------n bytes------>|<---r bytes--->|
+|<----n+r (where (n+r) mod 4 = 0)---->|\fP
+.DE
+.LP
+It   is  an error  to  encode  a  length  greater  than the maximum
+described in the specification.
+.NH 2
+\&String
+.IX XDR string
+.LP
+The standard defines a string of n (numbered 0 through n-1) ASCII
+bytes to be the number n encoded as an unsigned integer (as described
+above), and followed by the n bytes of the string.  Byte m of the
+string always precedes byte m+1 of the string, and byte 0 of the
+string always follows the string's length.  If n is not a multiple of
+four, then the n bytes are followed by enough (0 to 3) residual zero
+bytes, r, to make the total byte count a multiple of four.  Counted
+byte strings are declared as follows:
+.DS
+.ft CW
+string object<m>;
+.DE
+or
+.DS
+.ft CW
+string object<>;
+.DE
+The constant m denotes an upper bound of the number of bytes that a
+string may contain.  If m is not specified, as in the second
+declaration, it is assumed to be (2**32) - 1, the maximum length.
+The constant m would normally be found in a protocol specification.
+For example, a filing protocol may state that a file name can be no
+longer than 255 bytes, as follows:
+.DS
+.ft CW
+string filename<255>;
+.DE
+Which can be illustrated as:
+.ie t .DS
+.el .DS L
+\fIA String\fP
+
+\f(CW0     1     2     3     4     5   ...
++-----+-----+-----+-----+-----+-----+...+-----+-----+...+-----+
+|        length n       |byte0|byte1|...| n-1 |  0  |...|  0  |
++-----+-----+-----+-----+-----+-----+...+-----+-----+...+-----+
+|<-------4 bytes------->|<------n bytes------>|<---r bytes--->|
+|<----n+r (where (n+r) mod 4 = 0)---->|\fP
+.DE
+.LP
+It   is an  error  to  encode  a length greater  than   the maximum
+described in the specification.
+.NH 2
+\&Fixed-length Array
+.IX XDR "fixed-length array"
+.IX XDR "array, fixed length"
+.LP
+Declarations for fixed-length arrays of homogeneous elements are in
+the following form:
+.DS
+.ft CW
+type-name identifier[n];
+.DE
+Fixed-length arrays of elements numbered 0 through n-1 are encoded by
+individually encoding the elements of the array in their natural
+order, 0 through n-1.  Each element's size is a multiple of four
+bytes. Though all elements are of the same type, the elements may
+have different sizes.  For example, in a fixed-length array of
+strings, all elements are of type "string", yet each element will
+vary in its length.
+.ie t .DS
+.el .DS L
+\fIFixed-Length Array\fP
+
+\f(CW+---+---+---+---+---+---+---+---+...+---+---+---+---+
+|   element 0   |   element 1   |...|  element n-1  |
++---+---+---+---+---+---+---+---+...+---+---+---+---+
+|<--------------------n elements------------------->|\fP
+.DE
+.NH 2
+\&Variable-length Array
+.IX XDR "variable-length array"
+.IX XDR "array, variable length"
+.LP
+Counted arrays provide the ability to encode variable-length arrays
+of homogeneous elements.  The array is encoded as the element count n
+(an unsigned integer) followed by the encoding of each of the array's
+elements, starting with element 0 and progressing through element n-
+1.  The declaration for variable-length arrays follows this form:
+.DS
+.ft CW
+type-name identifier<m>;
+.DE
+or
+.DS
+.ft CW
+type-name identifier<>;
+.DE
+The constant m specifies the maximum acceptable element count of an
+array; if  m is not specified, as  in the second declaration, it is
+assumed to be (2**32) - 1.
+.ie t .DS
+.el .DS L
+\fICounted Array\fP
+
+\f(CW0  1  2  3
++--+--+--+--+--+--+--+--+--+--+--+--+...+--+--+--+--+
+|     n     | element 0 | element 1 |...|element n-1|
++--+--+--+--+--+--+--+--+--+--+--+--+...+--+--+--+--+
+|<-4 bytes->|<--------------n elements------------->|\fP
+.DE
+It is  an error to  encode  a  value of n that  is greater than the
+maximum described in the specification.
+.NH 2
+\&Structure
+.IX XDR structure
+.LP
+Structures are declared as follows:
+.DS
+.ft CW
+struct {
+	component-declaration-A;
+	component-declaration-B;
+	\&...
+} identifier;
+.DE
+The components of the structure are encoded in the order of their
+declaration in the structure.  Each component's size is a multiple of
+four bytes, though the components may be different sizes.
+.ie t .DS
+.el .DS L
+\fIStructure\fP
+
+\f(CW+-------------+-------------+...
+| component A | component B |...
++-------------+-------------+...\fP
+.DE
+.NH 2
+\&Discriminated Union
+.IX XDR "discriminated union"
+.IX XDR union discriminated
+.LP
+A discriminated union is a type composed of a discriminant followed
+by a type selected from a set of prearranged types according to the
+value of the discriminant.  The type of discriminant is either "int",
+"unsigned int", or an enumerated type, such as "bool".  The component
+types are called "arms" of the union, and are preceded by the value
+of the discriminant which implies their encoding.  Discriminated
+unions are declared as follows:
+.DS
+.ft CW
+union switch (discriminant-declaration) {
+	case discriminant-value-A:
+	arm-declaration-A;
+	case discriminant-value-B:
+	arm-declaration-B;
+	\&...
+	default: default-declaration;
+} identifier;
+.DE
+Each "case" keyword is followed by a legal value of the discriminant.
+The default arm is optional.  If it is not specified, then a valid
+encoding of the union cannot take on unspecified discriminant values.
+The size of the implied arm is always a multiple of four bytes.
+.LP
+The discriminated union is encoded as its discriminant followed by
+the encoding of the implied arm.
+.ie t .DS
+.el .DS L
+\fIDiscriminated Union\fP
+
+\f(CW0   1   2   3
++---+---+---+---+---+---+---+---+
+|  discriminant |  implied arm  |
++---+---+---+---+---+---+---+---+
+|<---4 bytes--->|\fP
+.DE
+.NH 2
+\&Void
+.IX XDR void
+.LP
+An XDR void is a 0-byte quantity.  Voids are useful for describing
+operations that take no data as input or no data as output. They are
+also useful in unions, where some arms may contain data and others do
+not.  The declaration is simply as follows:
+.DS
+.ft CW
+void;
+.DE
+Voids are illustrated as follows:
+.ie t .DS
+.el .DS L
+\fIVoid\fP
+
+\f(CW  ++
+  ||
+  ++
+--><-- 0 bytes\fP
+.DE
+.NH 2
+\&Constant
+.IX XDR constant
+.LP
+The data declaration for a constant follows this form:
+.DS
+.ft CW
+const name-identifier = n;
+.DE
+"const" is used to define a symbolic name for a constant; it does not
+declare any data.  The symbolic constant may be used anywhere a
+regular constant may be used.  For example, the following defines a
+symbolic constant DOZEN, equal to 12.
+.DS
+.ft CW
+const DOZEN = 12;
+.DE
+.NH 2
+\&Typedef
+.IX XDR typedef
+.LP
+"typedef" does not declare any data either, but serves to define new
+identifiers for declaring data. The syntax is:
+.DS
+.ft CW
+typedef declaration;
+.DE
+The new type name is actually the variable name in the declaration
+part of the typedef.  For example, the following defines a new type
+called "eggbox" using an existing type called "egg":
+.DS
+.ft CW
+typedef egg eggbox[DOZEN];
+.DE
+Variables declared using the new type name have the same type as the
+new type name would have in the typedef, if it was considered a
+variable.  For example, the following two declarations are equivalent
+in declaring the variable "fresheggs":
+.DS
+.ft CW
+eggbox  fresheggs;
+egg     fresheggs[DOZEN];
+.DE
+When a typedef involves a struct, enum, or union definition, there is
+another (preferred) syntax that may be used to define the same type.
+In general, a typedef of the following form:
+.DS
+.ft CW
+typedef <<struct, union, or enum definition>> identifier;
+.DE
+may be converted to the alternative form by removing the "typedef"
+part and placing the identifier after the "struct", "union", or
+"enum" keyword, instead of at the end.  For example, here are the two
+ways to define the type "bool":
+.DS
+.ft CW
+typedef enum {    /* \fIusing typedef\fP */
+	FALSE = 0,
+	TRUE = 1
+	} bool;
+
+enum bool {       /* \fIpreferred alternative\fP */
+	FALSE = 0,
+	TRUE = 1
+	};
+.DE
+The reason this syntax is preferred is one does not have to wait
+until the end of a declaration to figure out the name of the new
+type.
+.NH 2
+\&Optional-data
+.IX XDR "optional data"
+.IX XDR "data, optional"
+.LP
+Optional-data is one kind of union that occurs so frequently that we
+give it a special syntax of its own for declaring it.  It is declared
+as follows:
+.DS
+.ft CW
+type-name *identifier;
+.DE
+This is equivalent to the following union:
+.DS
+.ft CW
+union switch (bool opted) {
+	case TRUE:
+	type-name element;
+	case FALSE:
+	void;
+} identifier;
+.DE
+It is also equivalent to the following variable-length array
+declaration, since the boolean "opted" can be interpreted as the
+length of the array:
+.DS
+.ft CW
+type-name identifier<1>;
+.DE
+Optional-data is not so interesting in itself, but it is very useful
+for describing recursive data-structures such as linked-lists and
+trees.  For example, the following defines a type "stringlist" that
+encodes lists of arbitrary length strings:
+.DS
+.ft CW
+struct *stringlist {
+	string item<>;
+	stringlist next;
+};
+.DE
+It could have been equivalently declared as the following union:
+.DS
+.ft CW
+union stringlist switch (bool opted) {
+	case TRUE:
+		struct {
+			string item<>;
+			stringlist next;
+		} element;
+	case FALSE:
+		void;
+};
+.DE
+or as a variable-length array:
+.DS
+.ft CW
+struct stringlist<1> {
+	string item<>;
+	stringlist next;
+};
+.DE
+Both of these declarations obscure the intention of the stringlist
+type, so the optional-data declaration is preferred over both of
+them.  The optional-data type also has a close correlation to how
+recursive data structures are represented in high-level languages
+such as Pascal or C by use of pointers. In fact, the syntax is the
+same as that of the C language for pointers.
+.NH 2
+\&Areas for Future Enhancement
+.IX XDR futures
+.LP
+The XDR standard lacks representations for bit fields and bitmaps,
+since the standard is based on bytes.  Also missing are packed (or
+binary-coded) decimals.
+.LP
+The intent of the XDR standard was not to describe every kind of data
+that people have ever sent or will ever want to send from machine to
+machine. Rather, it only describes the most commonly used data-types
+of high-level languages such as Pascal or C so that applications
+written in these languages will be able to communicate easily over
+some medium.
+.LP
+One could imagine extensions to XDR that would let it describe almost
+any existing protocol, such as TCP.  The minimum necessary for this
+are support for different block sizes and byte-orders.  The XDR
+discussed here could then be considered the 4-byte big-endian member
+of a larger XDR family.
+.NH 1
+\&Discussion
+.sp 2
+.NH 2
+\&Why a Language for Describing Data?
+.IX XDR language
+.LP
+There are many advantages in using a data-description language such
+as  XDR  versus using  diagrams.   Languages are  more  formal than
+diagrams   and   lead  to less  ambiguous   descriptions  of  data.
+Languages are also easier  to understand and allow  one to think of
+other   issues instead of  the   low-level details of bit-encoding.
+Also,  there is  a close analogy  between the  types  of XDR and  a
+high-level language   such  as C   or    Pascal.   This makes   the
+implementation of XDR encoding and decoding modules an easier task.
+Finally, the language specification itself  is an ASCII string that
+can be passed from  machine to machine  to perform  on-the-fly data
+interpretation.
+.NH 2
+\&Why Only one Byte-Order for an XDR Unit?
+.IX XDR "byte order"
+.LP
+Supporting two byte-orderings requires a higher level protocol for
+determining in which byte-order the data is encoded.  Since XDR is
+not a protocol, this can't be done.  The advantage of this, though,
+is that data in XDR format can be written to a magnetic tape, for
+example, and any machine will be able to interpret it, since no
+higher level protocol is necessary for determining the byte-order.
+.NH 2
+\&Why does XDR use Big-Endian Byte-Order?
+.LP
+Yes, it is unfair, but having only one byte-order means you have to
+be unfair to somebody.  Many architectures, such as the Motorola
+68000 and IBM 370, support the big-endian byte-order.
+.NH 2
+\&Why is the XDR Unit Four Bytes Wide?
+.LP
+There is a tradeoff in choosing the XDR unit size.  Choosing a small
+size such as two makes the encoded data small, but causes alignment
+problems for machines that aren't aligned on these boundaries.  A
+large size such as eight means the data will be aligned on virtually
+every machine, but causes the encoded data to grow too big.  We chose
+four as a compromise.  Four is big enough to support most
+architectures efficiently, except for rare machines such as the
+eight-byte aligned Cray.  Four is also small enough to keep the
+encoded data restricted to a reasonable size.
+.NH 2
+\&Why must Variable-Length Data be Padded with Zeros?
+.IX XDR "variable-length data"
+.LP
+It is desirable that the same data encode into the same thing on all
+machines, so that encoded data can be meaningfully compared or
+checksummed.  Forcing the padded bytes to be zero ensures this.
+.NH 2
+\&Why is there No Explicit Data-Typing?
+.LP
+Data-typing has a relatively high cost for what small advantages it
+may have.  One cost is the expansion of data due to the inserted type
+fields.  Another is the added cost of interpreting these type fields
+and acting accordingly.  And most protocols already know what type
+they expect, so data-typing supplies only redundant information.
+However, one can still get the benefits of data-typing using XDR. One
+way is to encode two things: first a string which is the XDR data
+description of the encoded data, and then the encoded data itself.
+Another way is to assign a value to all the types in XDR, and then
+define a universal type which takes this value as its discriminant
+and for each value, describes the corresponding data type.
+.NH 1
+\&The XDR Language Specification
+.IX XDR language
+.sp 1
+.NH 2
+\&Notational Conventions
+.IX "XDR language" notation
+.LP
+This specification  uses an extended Backus-Naur Form  notation for
+describing the XDR language.   Here is  a brief description  of the
+notation:
+.IP  1.
+The characters
+.I | ,
+.I ( ,
+.I ) ,
+.I [ ,
+.I ] ,
+.I " ,
+and
+.I * 
+are special.
+.IP  2.
+Terminal symbols are  strings of any  characters surrounded by
+double quotes.
+.IP  3.
+Non-terminal symbols are strings of non-special characters.
+.IP  4.
+Alternative items are separated by a vertical bar ("\fI|\fP").
+.IP  5.
+Optional items are enclosed in brackets.
+.IP  6.
+Items are grouped together by enclosing them in parentheses.
+.IP  7.
+A
+.I * 
+following an item means  0 or more  occurrences of that item.
+.LP
+For example,  consider  the  following pattern:
+.DS L
+"a " "very" (", " " very")* [" cold " "and"]  " rainy " ("day" | "night")
+.DE
+.LP
+An infinite  number of  strings match  this pattern. A few  of them
+are:
+.DS
+"a very rainy day"
+"a very, very rainy day"
+"a very cold and  rainy day"
+"a very, very, very cold and  rainy night"
+.DE
+.NH 2
+\&Lexical Notes
+.IP  1.
+Comments begin with '/*' and terminate with '*/'.
+.IP  2.
+White space serves to separate items and is otherwise ignored.
+.IP  3.
+An identifier is a letter followed by  an optional sequence of
+letters, digits or underbar ('_').  The case of identifiers is
+not ignored.
+.IP  4.
+A  constant is  a  sequence  of  one  or  more decimal digits,
+optionally preceded by a minus-sign ('-').
+.NH 2
+\&Syntax Information
+.IX "XDR language" syntax
+.DS
+.ft CW
+declaration:
+	type-specifier identifier
+	| type-specifier identifier "[" value "]"
+	| type-specifier identifier "<" [ value ] ">"
+	| "opaque" identifier "[" value "]"
+	| "opaque" identifier "<" [ value ] ">"
+	| "string" identifier "<" [ value ] ">"
+	| type-specifier "*" identifier
+	| "void"
+.DE
+.DS
+.ft CW
+value:
+	constant
+	| identifier
+
+type-specifier:
+	  [ "unsigned" ] "int"
+	| [ "unsigned" ] "hyper"
+	| "float"
+	| "double"
+	| "bool"
+	| enum-type-spec
+	| struct-type-spec
+	| union-type-spec
+	| identifier
+.DE
+.DS
+.ft CW
+enum-type-spec:
+	"enum" enum-body
+
+enum-body:
+	"{"
+	( identifier "=" value )
+	( "," identifier "=" value )*
+	"}"
+.DE
+.DS
+.ft CW
+struct-type-spec:
+	"struct" struct-body
+
+struct-body:
+	"{"
+	( declaration ";" )
+	( declaration ";" )*
+	"}"
+.DE
+.DS
+.ft CW
+union-type-spec:
+	"union" union-body
+
+union-body:
+	"switch" "(" declaration ")" "{"
+	( "case" value ":" declaration ";" )
+	( "case" value ":" declaration ";" )*
+	[ "default" ":" declaration ";" ]
+	"}"
+
+constant-def:
+	"const" identifier "=" constant ";"
+.DE
+.DS
+.ft CW
+type-def:
+	"typedef" declaration ";"
+	| "enum" identifier enum-body ";"
+	| "struct" identifier struct-body ";"
+	| "union" identifier union-body ";"
+
+definition:
+	type-def
+	| constant-def
+
+specification:
+	definition *
+.DE
+.NH 3
+\&Syntax Notes
+.IX "XDR language" syntax
+.LP
+.IP  1.
+The following are keywords and cannot be used as identifiers:
+"bool", "case", "const", "default", "double", "enum", "float",
+"hyper", "opaque", "string", "struct", "switch", "typedef", "union",
+"unsigned" and "void".
+.IP  2.
+Only unsigned constants may be used as size specifications for
+arrays.  If an identifier is used, it must have been declared
+previously as an unsigned constant in a "const" definition.
+.IP  3.
+Constant and type identifiers within the scope of a specification
+are in the same name space and must be declared uniquely within this
+scope.
+.IP  4.
+Similarly, variable names must  be unique within  the scope  of
+struct and union declarations. Nested struct and union declarations
+create new scopes.
+.IP  5.
+The discriminant of a union must be of a type that evaluates to
+an integer. That is, "int", "unsigned int", "bool", an enumerated
+type or any typedefed type that evaluates to one of these is legal.
+Also, the case values must be one of the legal values of the
+discriminant.  Finally, a case value may not be specified more than
+once within the scope of a union declaration.
+.NH 1
+\&An Example of an XDR Data Description
+.LP
+Here is a short XDR data description of a thing called a "file",
+which might be used to transfer files from one machine to another.
+.ie t .DS
+.el .DS L
+.ft CW
+
+const MAXUSERNAME = 32;     /*\fI max length of a user name \fP*/
+const MAXFILELEN = 65535;   /*\fI max length of a file      \fP*/
+const MAXNAMELEN = 255;     /*\fI max length of a file name \fP*/
+
+.ft I
+/*
+ * Types of files:
+ */
+.ft CW
+
+enum filekind {
+	TEXT = 0,       /*\fI ascii data \fP*/
+	DATA = 1,       /*\fI raw data   \fP*/
+	EXEC = 2        /*\fI executable \fP*/
+};
+
+.ft I
+/*
+ * File information, per kind of file:
+ */
+.ft CW
+
+union filetype switch (filekind kind) {
+	case TEXT:
+		void;                           /*\fI no extra information \fP*/
+	case DATA:
+		string creator<MAXNAMELEN>;     /*\fI data creator         \fP*/
+	case EXEC:
+		string interpretor<MAXNAMELEN>; /*\fI program interpretor  \fP*/
+};
+
+.ft I
+/*
+ * A complete file:
+ */
+.ft CW
+
+struct file {
+	string filename<MAXNAMELEN>; /*\fI name of file \fP*/
+	filetype type;               /*\fI info about file \fP*/
+	string owner<MAXUSERNAME>;   /*\fI owner of file   \fP*/
+	opaque data<MAXFILELEN>;     /*\fI file data       \fP*/
+};
+.DE
+.LP
+Suppose now that there is  a user named  "john" who wants to  store
+his lisp program "sillyprog" that contains just  the data "(quit)".
+His file would be encoded as follows:
+.TS
+box tab (&) ;
+lfI lfI lfI lfI
+rfL rfL rfL l .
+Offset&Hex Bytes&ASCII&Description
+_
+0&00 00 00 09&....&Length of filename = 9
+4&73 69 6c 6c&sill&Filename characters
+8&79 70 72 6f&ypro& ... and more characters ...
+12&67 00 00 00&g...& ... and 3 zero-bytes of fill
+16&00 00 00 02&....&Filekind is EXEC = 2
+20&00 00 00 04&....&Length of interpretor = 4
+24&6c 69 73 70&lisp&Interpretor characters
+28&00 00 00 04&....&Length of owner = 4
+32&6a 6f 68 6e&john&Owner characters
+36&00 00 00 06&....&Length of file data = 6
+40&28 71 75 69&(qui&File data bytes ...
+44&74 29 00 00&t)..& ... and 2 zero-bytes of fill
+.TE
+.NH 1
+\&References
+.LP
+[1]  Brian W. Kernighan & Dennis M. Ritchie, "The C Programming
+Language", Bell Laboratories, Murray Hill, New Jersey, 1978.
+.LP
+[2]  Danny Cohen, "On Holy Wars and a Plea for Peace", IEEE Computer,
+October 1981.
+.LP
+[3]  "IEEE Standard for Binary Floating-Point Arithmetic", ANSI/IEEE
+Standard 754-1985, Institute of Electrical and Electronics
+Engineers, August 1985.
+.LP
+[4]  "Courier: The Remote Procedure Call Protocol", XEROX
+Corporation, XSIS 038112, December 1981.
diff --git a/share/doc/psd/26.rpcrfc/Makefile b/share/doc/psd/26.rpcrfc/Makefile
index 79214f1..3ffdc27 100644
--- a/share/doc/psd/26.rpcrfc/Makefile
+++ b/share/doc/psd/26.rpcrfc/Makefile
@@ -4,6 +4,5 @@ VOLUME=		psd/26.rpcrfc
 SRCS=		stubs rpc.rfc.ms
 MACROS=		-ms
 USE_TBL=
-SRCDIR=		${.CURDIR}/../../../../lib/libc/rpc/PSD.doc
 
 .include <bsd.doc.mk>
diff --git a/share/doc/psd/26.rpcrfc/rpc.rfc.ms b/share/doc/psd/26.rpcrfc/rpc.rfc.ms
new file mode 100644
index 0000000..9a948bd
--- /dev/null
+++ b/share/doc/psd/26.rpcrfc/rpc.rfc.ms
@@ -0,0 +1,1304 @@
+.\"
+.\" Must use  --  tbl  --  with this one
+.\"
+.\" @(#)rpc.rfc.ms	2.2 88/08/05 4.0 RPCSRC
+.\" $FreeBSD$
+.\"
+.de BT
+.if \\n%=1 .tl ''- % -''
+..
+.ND
+.\" prevent excess underlining in nroff
+.if n .fp 2 R
+.OH 'Remote Procedure Calls: Protocol Specification''Page %'
+.EH 'Page %''Remote Procedure Calls: Protocol Specification'
+.if \n%=1 .bp
+.SH
+\&Remote Procedure Calls: Protocol Specification
+.LP
+.NH 0
+\&Status of this Memo
+.LP
+Note: This chapter specifies a protocol that Sun Microsystems, Inc.,
+and others are using.  
+It has been designated RFC1050 by the ARPA Network
+Information Center.
+.LP
+.NH 1
+\&Introduction
+.LP
+This chapter specifies  a  message protocol  used in implementing
+Sun's Remote Procedure Call (RPC) package.  (The message protocol is
+specified with the External Data Representation (XDR) language.
+See the
+.I "External Data Representation Standard: Protocol Specification"
+for the details.  Here, we assume that  the  reader is familiar  
+with XDR and do not attempt to justify it or its uses).  The paper
+by Birrell and Nelson [1]  is recommended as an  excellent background
+to  and justification of RPC.
+.NH 2
+\&Terminology
+.LP
+This chapter discusses servers, services, programs, procedures,
+clients, and versions.  A server is a piece of software where network
+services are implemented.  A network service is a collection of one
+or more remote programs.  A remote program implements one or more
+remote procedures; the procedures, their parameters, and results are
+documented in the specific program's protocol specification (see the
+\fIPort Mapper Program Protocol\fP\, below, for an example).  Network
+clients are pieces of software that initiate remote procedure calls
+to services.  A server may support more than one version of a remote
+program in order to be forward compatible with changing protocols.
+.LP
+For example, a network file service may be composed of two programs.
+One program may deal with high-level applications such as file system
+access control and locking.  The other may deal with low-level file
+IO and have procedures like "read" and "write".  A client machine of
+the network file service would call the procedures associated with
+the two programs of the service on behalf of some user on the client
+machine.
+.NH 2
+\&The RPC Model
+.LP
+The remote procedure call model is similar to the local procedure
+call model.  In the local case, the caller places arguments to a
+procedure in some well-specified location (such as a result
+register).  It then transfers control to the procedure, and
+eventually gains back control.  At that point, the results of the
+procedure are extracted from the well-specified location, and the
+caller continues execution.
+.LP
+The remote procedure call is similar, in that one thread of control
+logically winds through two processes\(emone is the caller's process,
+the other is a server's process.  That is, the caller process sends a
+call message to the server process and waits (blocks) for a reply
+message.  The call message contains the procedure's parameters, among
+other things.  The reply message contains the procedure's results,
+among other things.  Once the reply message is received, the results
+of the procedure are extracted, and caller's execution is resumed.
+.LP
+On the server side, a process is dormant awaiting the arrival of a
+call message.  When one arrives, the server process extracts the
+procedure's parameters, computes the results, sends a reply message,
+and then awaits the next call message.
+.LP
+Note that in this model, only one of the two processes is active at
+any given time.  However, this model is only given as an example.
+The RPC protocol makes no restrictions on the concurrency model
+implemented, and others are possible.  For example, an implementation
+may choose to have RPC calls be asynchronous, so that the client may
+do useful work while waiting for the reply from the server.  Another
+possibility is to have the server create a task to process an
+incoming request, so that the server can be free to receive other
+requests.
+.NH 2
+\&Transports and Semantics
+.LP
+The RPC protocol is independent of transport protocols.  That is, RPC
+does not care how a message is passed from one process to another.
+The protocol deals only with specification and interpretation of
+messages.
+.LP
+It is important to point out that RPC does not try to implement any
+kind of reliability and that the application must be aware of the
+type of transport protocol underneath RPC.  If it knows it is running
+on top of a reliable transport such as TCP/IP[6], then most of the
+work is already done for it.  On the other hand, if it is running on
+top of an unreliable transport such as UDP/IP[7], it must implement
+is own retransmission and time-out policy as the RPC layer does not
+provide this service.
+.LP
+Because of transport independence, the RPC protocol does not attach
+specific semantics to the remote procedures or their execution.
+Semantics can be inferred from (but should be explicitly specified
+by) the underlying transport protocol.  For example, consider RPC
+running on top of an unreliable transport such as UDP/IP.  If an
+application retransmits RPC messages after short time-outs, the only
+thing it can infer if it receives no reply is that the procedure was
+executed zero or more times.  If it does receive a reply, then it can
+infer that the procedure was executed at least once.
+.LP
+A server may wish to remember previously granted requests from a
+client and not regrant them in order to insure some degree of
+execute-at-most-once semantics.  A server can do this by taking
+advantage of the transaction ID that is packaged with every RPC
+request.  The main use of this transaction is by the client RPC layer
+in matching replies to requests.  However, a client application may
+choose to reuse its previous transaction ID when retransmitting a
+request.  The server application, knowing this fact, may choose to
+remember this ID after granting a request and not regrant requests
+with the same ID in order to achieve some degree of
+execute-at-most-once semantics.  The server is not allowed to examine
+this ID in any other way except as a test for equality.
+.LP
+On the other hand, if using a reliable transport such as TCP/IP, the
+application can infer from a reply message that the procedure was
+executed exactly once, but if it receives no reply message, it cannot
+assume the remote procedure was not executed.  Note that even if a
+connection-oriented protocol like TCP is used, an application still
+needs time-outs and reconnection to handle server crashes.
+.LP
+There are other possibilities for transports besides datagram- or
+connection-oriented protocols.  For example, a request-reply protocol
+such as VMTP[2] is perhaps the most natural transport for RPC.
+.SH
+.I
+NOTE:  At Sun, RPC is currently implemented on top of both TCP/IP
+and UDP/IP transports.
+.LP
+.NH 2
+\&Binding and Rendezvous Independence
+.LP
+The act of binding a client to a service is NOT part of the remote
+procedure call specification.  This important and necessary function
+is left up to some higher-level software.  (The software may use RPC
+itself\(emsee the \fIPort Mapper Program Protocol\fP\, below).
+.LP
+Implementors should think of the RPC protocol as the jump-subroutine
+instruction ("JSR") of a network; the loader (binder) makes JSR
+useful, and the loader itself uses JSR to accomplish its task.
+Likewise, the network makes RPC useful, using RPC to accomplish this
+task.
+.NH 2
+\&Authentication
+.LP
+The RPC protocol provides the fields necessary for a client to
+identify itself to a service and vice-versa.  Security and access
+control mechanisms can be built on top of the message authentication.
+Several different authentication protocols can be supported.  A field
+in the RPC header indicates which protocol is being used.  More
+information on specific authentication protocols can be found in the
+\fIAuthentication Protocols\fP\,
+below.
+.KS
+.NH 1
+\&RPC Protocol Requirements
+.LP
+The RPC protocol must provide for the following:
+.IP  1.
+Unique specification of a procedure to be called.
+.IP  2.
+Provisions for matching response messages to request messages.
+.KE
+.IP  3.
+Provisions for authenticating the caller to service and vice-versa.
+.LP
+Besides these requirements, features that detect the following are
+worth supporting because of protocol roll-over errors, implementation
+bugs, user error, and network administration:
+.IP  1.
+RPC protocol mismatches.
+.IP  2.
+Remote program protocol version mismatches.
+.IP  3.
+Protocol errors (such as misspecification of a procedure's parameters).
+.IP  4.
+Reasons why remote authentication failed.
+.IP  5.
+Any other reasons why the desired procedure was not called.
+.NH 2
+\&Programs and Procedures
+.LP
+The RPC call message has three unsigned fields:  remote program
+number, remote program version number, and remote procedure number.
+The three fields uniquely identify the procedure to be called.
+Program numbers are administered by some central authority (like
+Sun).  Once an implementor has a program number, he can implement his
+remote program; the first implementation would most likely have the
+version number of 1.  Because most new protocols evolve into better,
+stable, and mature protocols, a version field of the call message
+identifies which version of the protocol the caller is using.
+Version numbers make speaking old and new protocols through the same
+server process possible.
+.LP
+The procedure number identifies the procedure to be called.  These
+numbers are documented in the specific program's protocol
+specification.  For example, a file service's protocol specification
+may state that its procedure number 5 is "read" and procedure number
+12 is "write".
+.LP
+Just as remote program protocols may change over several versions,
+the actual RPC message protocol could also change.  Therefore, the
+call message also has in it the RPC version number, which is always
+equal to two for the version of RPC described here.
+.LP
+The reply message to a request  message  has enough  information to
+distinguish the following error conditions:
+.IP  1.
+The remote implementation of RPC does speak protocol version 2.
+The lowest and highest supported RPC version numbers are returned.
+.IP  2.
+The remote program is not available on the remote system.
+.IP  3.
+The remote program does not support the requested version number.
+The lowest and highest supported remote program version numbers are
+returned.
+.IP  4.
+The requested procedure number does not exist.  (This is usually a
+caller side protocol or programming error.)
+.IP  5.
+The parameters to the remote procedure appear to be garbage from the
+server's point of view.  (Again, this is usually caused by a
+disagreement about the protocol between client and service.)
+.NH 2
+\&Authentication
+.LP
+Provisions for authentication of caller to service and vice-versa are
+provided as a part of the RPC protocol.  The call message has two
+authentication fields, the credentials and verifier.  The reply
+message has one authentication field, the response verifier.  The RPC
+protocol specification defines all three fields to be the following
+opaque type:
+.DS
+.ft CW
+.vs 11
+enum auth_flavor {
+    AUTH_NULL        = 0,
+    AUTH_UNIX        = 1,
+    AUTH_SHORT       = 2,
+    AUTH_DES         = 3
+    /* \fIand more to be defined\fP */
+};
+
+struct opaque_auth {
+    auth_flavor flavor;
+    opaque body<400>;
+};
+.DE
+.LP
+In simple English, any
+.I opaque_auth 
+structure is an 
+.I auth_flavor 
+enumeration followed by bytes which are  opaque to the RPC protocol
+implementation.
+.LP
+The interpretation and semantics  of the data contained  within the
+authentication   fields  is specified  by  individual,  independent
+authentication  protocol specifications.   (See 
+\fIAuthentication Protocols\fP\,
+below, for definitions of the various authentication protocols.)
+.LP
+If authentication parameters were   rejected, the  response message
+contains information stating why they were rejected.
+.NH 2
+\&Program Number Assignment
+.LP
+Program numbers are given out in groups of
+.I 0x20000000 
+(decimal 536870912) according to the following chart:
+.TS
+box tab (&) ;
+lfI lfI
+rfL cfI .
+Program Numbers&Description
+_
+.sp .5
+0 - 1fffffff&Defined by Sun
+20000000 - 3fffffff&Defined by user
+40000000 - 5fffffff&Transient
+60000000 - 7fffffff&Reserved
+80000000 - 9fffffff&Reserved
+a0000000 - bfffffff&Reserved
+c0000000 - dfffffff&Reserved
+e0000000 - ffffffff&Reserved
+.TE
+.LP
+The first group is a range of numbers administered by Sun
+Microsystems and should be identical for all sites.  The second range
+is for applications peculiar to a particular site.  This range is
+intended primarily for debugging new programs.  When a site develops
+an application that might be of general interest, that application
+should be given an assigned number in the first range.  The third
+group is for applications that generate program numbers dynamically.
+The final groups are reserved for future use, and should not be used.
+.NH 2
+\&Other Uses of the RPC Protocol
+.LP
+The intended use of this protocol is for calling remote procedures.
+That is, each call message is matched with a response message.
+However, the protocol itself is a message-passing protocol with which
+other (non-RPC) protocols can be implemented.  Sun currently uses, or
+perhaps abuses, the RPC message protocol for the following two
+(non-RPC) protocols:  batching (or pipelining) and broadcast RPC.
+These two protocols are discussed but not defined below.
+.NH 3
+\&Batching
+.LP
+Batching allows a client to send an arbitrarily large sequence of
+call messages to a server; batching typically uses reliable byte
+stream protocols (like TCP/IP) for its transport.  In the case of
+batching, the client never waits for a reply from the server, and the
+server does not send replies to batch requests.  A sequence of batch
+calls is usually terminated by a legitimate RPC in order to flush the
+pipeline (with positive acknowledgement).
+.NH 3
+\&Broadcast RPC
+.LP
+In broadcast RPC-based protocols, the client sends a broadcast packet
+to the network and waits for numerous replies.  Broadcast RPC uses
+unreliable, packet-based protocols (like UDP/IP) as its transports.
+Servers that support broadcast protocols only respond when the
+request is successfully processed, and are silent in the face of
+errors.  Broadcast RPC uses the Port Mapper RPC service to achieve
+its semantics.  See the \fIPort Mapper Program Protocol\fP\, below,
+for more information.
+.KS
+.NH 1
+\&The RPC Message Protocol
+.LP
+This section defines the RPC message protocol in the XDR data
+description language.  The message is defined in a top-down style.
+.ie t .DS
+.el .DS L
+.ft CW
+enum msg_type {
+	CALL  = 0,
+	REPLY = 1
+};
+
+.ft I
+/*
+* A reply to a call message can take on two forms:
+* The message was either accepted or rejected.
+*/
+.ft CW
+enum reply_stat {
+	MSG_ACCEPTED = 0,
+	MSG_DENIED   = 1
+};
+
+.ft I
+/*
+* Given that a call message was accepted,  the following is the
+* status of an attempt to call a remote procedure.
+*/
+.ft CW
+enum accept_stat {
+	SUCCESS       = 0, /* \fIRPC executed successfully       \fP*/
+	PROG_UNAVAIL  = 1, /* \fIremote hasn't exported program  \fP*/
+	PROG_MISMATCH = 2, /* \fIremote can't support version #  \fP*/
+	PROC_UNAVAIL  = 3, /* \fIprogram can't support procedure \fP*/
+	GARBAGE_ARGS  = 4  /* \fIprocedure can't decode params   \fP*/
+};
+.DE
+.ie t .DS
+.el .DS L
+.ft I
+/*
+* Reasons why a call message was rejected:
+*/
+.ft CW
+enum reject_stat {
+	RPC_MISMATCH = 0, /* \fIRPC version number != 2          \fP*/
+	AUTH_ERROR = 1    /* \fIremote can't authenticate caller \fP*/
+};
+
+.ft I
+/*
+* Why authentication failed:
+*/
+.ft CW
+enum auth_stat {
+	AUTH_BADCRED      = 1,  /* \fIbad credentials \fP*/
+	AUTH_REJECTEDCRED = 2,  /* \fIclient must begin new session \fP*/
+	AUTH_BADVERF      = 3,  /* \fIbad verifier \fP*/
+	AUTH_REJECTEDVERF = 4,  /* \fIverifier expired or replayed  \fP*/
+	AUTH_TOOWEAK      = 5   /* \fIrejected for security reasons \fP*/
+};
+.DE
+.KE
+.ie t .DS
+.el .DS L
+.ft I
+/*
+* The  RPC  message: 
+* All   messages  start with   a transaction  identifier,  xid,
+* followed  by a  two-armed  discriminated union.   The union's
+* discriminant is a  msg_type which switches to  one of the two
+* types   of the message.   The xid  of a \fIREPLY\fP  message always
+* matches  that of the initiating \fICALL\fP   message.   NB: The xid
+* field is only  used for clients  matching reply messages with
+* call messages  or for servers detecting  retransmissions; the
+* service side  cannot treat this id  as any type   of sequence
+* number.
+*/
+.ft CW
+struct rpc_msg {
+	unsigned int xid;
+	union switch (msg_type mtype) {
+		case CALL:
+			call_body cbody;
+		case REPLY:  
+			reply_body rbody;
+	} body;
+};
+.DE
+.ie t .DS
+.el .DS L
+.ft I
+/*
+* Body of an RPC request call: 
+* In version 2 of the  RPC protocol specification, rpcvers must
+* be equal to 2.  The  fields prog,  vers, and proc specify the
+* remote program, its version number, and the  procedure within
+* the remote program to be called.  After these  fields are two
+* authentication  parameters: cred (authentication credentials)
+* and verf  (authentication verifier).  The  two authentication
+* parameters are   followed by  the  parameters  to  the remote
+* procedure,  which  are specified  by  the  specific   program
+* protocol.
+*/
+.ft CW
+struct call_body {
+	unsigned int rpcvers;  /* \fImust be equal to two (2) \fP*/
+	unsigned int prog;
+	unsigned int vers;
+	unsigned int proc;
+	opaque_auth cred;
+	opaque_auth verf;
+	/* \fIprocedure specific parameters start here \fP*/
+};
+.DE
+.ie t .DS
+.el .DS L
+.ft I
+/*
+* Body of a reply to an RPC request:
+* The call message was either accepted or rejected.
+*/
+.ft CW
+union reply_body switch (reply_stat stat) {
+	case MSG_ACCEPTED:  
+		accepted_reply areply;
+	case MSG_DENIED:  
+		rejected_reply rreply;
+} reply;
+.DE
+.ie t .DS
+.el .DS L
+.ft I
+/*
+* Reply to   an RPC request  that  was accepted  by the server:
+* there could be an error even though the request was accepted.
+* The first field is an authentication verifier that the server
+* generates in order to  validate itself  to the caller.  It is
+* followed by    a  union whose     discriminant  is   an  enum
+* accept_stat.  The  \fISUCCESS\fP  arm of    the union  is  protocol
+* specific.  The \fIPROG_UNAVAIL\fP, \fIPROC_UNAVAIL\fP, and \fIGARBAGE_ARGP\fP
+* arms of the union are void.   The \fIPROG_MISMATCH\fP arm specifies
+* the lowest and highest version numbers of the  remote program
+* supported by the server.
+*/
+.ft CW
+struct accepted_reply {
+	opaque_auth verf;
+	union switch (accept_stat stat) {
+		case SUCCESS:
+			opaque results[0];
+			/* \fIprocedure-specific results start here\fP */
+		case PROG_MISMATCH:
+			struct {
+				unsigned int low;
+				unsigned int high;
+			} mismatch_info;
+		default:
+.ft I
+			/*
+			* Void.  Cases include \fIPROG_UNAVAIL, PROC_UNAVAIL\fP,
+			* and \fIGARBAGE_ARGS\fP.
+			*/
+.ft CW
+			void;
+	} reply_data;
+};
+.DE
+.ie t .DS
+.el .DS L
+.ft I
+/*
+* Reply to an RPC request that was rejected by the server: 
+* The request  can   be rejected for   two reasons:  either the
+* server   is not  running a   compatible  version  of the  RPC
+* protocol    (\fIRPC_MISMATCH\fP), or    the  server   refuses    to
+* authenticate the  caller  (\fIAUTH_ERROR\fP).  In  case of  an  RPC
+* version mismatch,  the server returns the  lowest and highest
+* supported    RPC  version    numbers.  In   case   of refused
+* authentication, failure status is returned.
+*/
+.ft CW
+union rejected_reply switch (reject_stat stat) {
+	case RPC_MISMATCH:
+		struct {
+			unsigned int low;
+			unsigned int high;
+		} mismatch_info;
+	case AUTH_ERROR: 
+		auth_stat stat;
+};
+.DE
+.NH 1
+\&Authentication Protocols
+.LP
+As previously stated, authentication parameters are opaque, but
+open-ended to the rest of the RPC protocol.  This section defines
+some "flavors" of authentication implemented at (and supported by)
+Sun.  Other sites are free to invent new authentication types, with
+the same rules of flavor number assignment as there is for program
+number assignment.
+.NH 2
+\&Null Authentication
+.LP
+Often calls must be made where the caller does not know who he is or
+the server does not care who the caller is.  In this case, the flavor
+value (the discriminant of the \fIopaque_auth\fP's union) of the RPC
+message's credentials, verifier, and response verifier is
+.I AUTH_NULL .
+The  bytes of the opaque_auth's body  are undefined.
+It is recommended that the opaque length be zero.
+.NH 2
+\&UNIX Authentication
+.LP
+The caller of a remote procedure may wish to identify himself as he
+is identified on a UNIX system.  The  value of the credential's
+discriminant of an RPC call  message is  
+.I AUTH_UNIX .
+The bytes of
+the credential's opaque body encode the following structure:
+.DS
+.ft CW
+struct auth_unix {
+	unsigned int stamp;
+	string machinename<255>;
+	unsigned int uid;
+	unsigned int gid;
+	unsigned int gids<10>;
+};
+.DE
+The 
+.I stamp 
+is an  arbitrary    ID which the  caller machine   may
+generate.  The 
+.I machinename 
+is the  name of the  caller's machine (like  "krypton").  The 
+.I uid 
+is  the caller's effective user  ID.  The  
+.I gid 
+is  the caller's effective  group  ID.  The 
+.I gids 
+is  a
+counted array of groups which contain the caller as  a member.  The
+verifier accompanying the  credentials  should  be  of  
+.I AUTH_NULL
+(defined above).
+.LP
+The value of the discriminant of  the response verifier received in
+the  reply  message  from  the    server  may   be   
+.I AUTH_NULL 
+or
+.I AUTH_SHORT .
+In  the  case  of 
+.I AUTH_SHORT ,
+the bytes of the response verifier's string encode an opaque
+structure.  This new opaque structure may now be passed to the server
+instead of the original
+.I AUTH_UNIX
+flavor credentials.  The server keeps a cache which maps shorthand
+opaque structures (passed back by way of an
+.I AUTH_SHORT
+style response verifier) to the original credentials of the caller.
+The caller can save network bandwidth and server cpu cycles by using
+the new credentials.
+.LP
+The server may flush the shorthand opaque structure at any time.  If
+this happens, the remote procedure call message will be rejected due
+to an authentication error.  The reason for the failure will be
+.I AUTH_REJECTEDCRED .
+At this point, the caller may wish to try the original
+.I AUTH_UNIX
+style of credentials.
+.KS
+.NH 2
+\&DES Authentication
+.LP
+UNIX authentication suffers from two major problems:
+.IP  1.
+The naming is too UNIX-system oriented.
+.IP  2.
+There is no verifier, so credentials can easily be faked.
+.LP
+DES authentication attempts to fix these two problems.
+.KE
+.NH 3
+\&Naming
+.LP
+The first problem is handled by addressing the caller by a simple
+string of characters instead of by an operating system specific
+integer.  This string of characters is known as the "netname" or
+network name of the caller.  The server is not allowed to interpret
+the contents of the caller's name in any other way except to
+identify the caller.  Thus, netnames should be unique for every
+caller in the internet.
+.LP
+It is up to each operating system's implementation of DES
+authentication to generate netnames for its users that insure this
+uniqueness when they call upon remote servers.  Operating systems
+already know how to distinguish users local to their systems.  It is
+usually a simple matter to extend this mechanism to the network.
+For example, a UNIX user at Sun with a user ID of 515 might be
+assigned the following netname: "unix.515@sun.com".  This netname
+contains three items that serve to insure it is unique.  Going
+backwards, there is only one naming domain called "sun.com" in the
+internet.  Within this domain, there is only one UNIX user with
+user ID 515.  However, there may be another user on another
+operating system, for example VMS, within the same naming domain
+that, by coincidence, happens to have the same user ID.  To insure
+that these two users can be distinguished we add the operating
+system name.  So one user is "unix.515@sun.com" and the other is
+"vms.515@sun.com".
+.LP
+The first field is actually a naming method rather than an
+operating system name.  It just happens that today there is almost
+a one-to-one correspondence between naming methods and operating
+systems.  If the world could agree on a naming standard, the first
+field could be the name of that standard, instead of an operating
+system name.
+.LP
+.NH 3
+\&DES Authentication Verifiers
+.LP
+Unlike UNIX authentication, DES authentication does have a verifier
+so the server can validate the client's credential (and
+vice-versa).  The contents of this verifier is primarily an
+encrypted timestamp.  The server can decrypt this timestamp, and if
+it is close to what the real time is, then the client must have
+encrypted it correctly.  The only way the client could encrypt it
+correctly is to know the "conversation key" of the RPC session.  And
+if the client knows the conversation key, then it must be the real
+client.
+.LP
+The conversation key is a DES [5] key which the client generates
+and notifies the server of in its first RPC call.  The conversation
+key is encrypted using a public key scheme in this first
+transaction.  The particular public key scheme used in DES
+authentication is Diffie-Hellman [3] with 192-bit keys.  The
+details of this encryption method are described later.
+.LP
+The client and the server need the same notion of the current time
+in order for all of this to work.  If network time synchronization
+cannot be guaranteed, then client can synchronize with the server
+before beginning the conversation, perhaps by consulting the
+Internet Time Server (TIME[4]).
+.LP
+The way a server determines if a client timestamp is valid is
+somewhat complicated.  For any other transaction but the first, the
+server just checks for two things:
+.IP  1.
+the timestamp is greater than the one previously seen from the
+same client.
+.IP  2.
+the timestamp has not expired.
+.LP
+A timestamp is expired if the server's time is later than the sum
+of the client's timestamp plus what is known as the client's
+"window".  The "window" is a number the client passes (encrypted)
+to the server in its first transaction.  You can think of it as a
+lifetime for the credential.
+.LP
+This explains everything but the first transaction.  In the first
+transaction, the server checks only that the timestamp has not
+expired.  If this was all that was done though, then it would be
+quite easy for the client to send random data in place of the
+timestamp with a fairly good chance of succeeding.  As an added
+check, the client sends an encrypted item in the first transaction
+known as the "window verifier" which must be equal to the window
+minus 1, or the server will reject the credential.
+.LP
+The client too must check the verifier returned from the server to
+be sure it is legitimate.  The server sends back to the client the
+encrypted timestamp it received from the client, minus one second.
+If the client gets anything different than this, it will reject it.
+.LP
+.NH 3
+\&Nicknames and Clock Synchronization
+.LP
+After the first transaction, the server's DES authentication
+subsystem returns in its verifier to the client an integer
+"nickname" which the client may use in its further transactions
+instead of passing its netname, encrypted DES key and window every
+time.  The nickname is most likely an index into a table on the
+server which stores for each client its netname, decrypted DES key
+and window.
+.LP
+Though they originally were synchronized, the client's and server's
+clocks can get out of sync again.  When this happens the client RPC
+subsystem most likely will get back
+.I RPC_AUTHERROR 
+at which point it should resynchronize.
+.LP
+A client may still get the
+.I RPC_AUTHERROR 
+error even though it is
+synchronized with the server.  The reason is that the server's
+nickname table is a limited size, and it may flush entries whenever
+it wants.  A client should resend its original credential in this
+case and the server will give it a new nickname.  If a server
+crashes, the entire nickname table gets flushed, and all clients
+will have to resend their original credentials.
+.KS
+.NH 3
+\&DES Authentication Protocol (in XDR language)
+.ie t .DS
+.el .DS L
+.ft I
+/*
+* There are two kinds of credentials: one in which the client uses
+* its full network name, and one in which it uses its "nickname"
+* (just an unsigned integer) given to it by the server.  The
+* client must use its fullname in its first transaction with the
+* server, in which the server will return to the client its
+* nickname.  The client may use its nickname in all further
+* transactions with the server.  There is no requirement to use the
+* nickname, but it is wise to use it for performance reasons.
+*/
+.ft CW
+enum authdes_namekind {
+	ADN_FULLNAME = 0,
+	ADN_NICKNAME = 1
+};
+
+.ft I
+/*
+* A 64-bit block of encrypted DES data
+*/
+.ft CW
+typedef opaque des_block[8];
+
+.ft I
+/*
+* Maximum length of a network user's name
+*/
+.ft CW
+const MAXNETNAMELEN = 255;
+
+.ft I
+/*
+* A fullname contains the network name of the client, an encrypted
+* conversation key and the window.  The window is actually a
+* lifetime for the credential.  If the time indicated in the
+* verifier timestamp plus the window has past, then the server
+* should expire the request and not grant it.  To insure that
+* requests are not replayed, the server should insist that
+* timestamps are greater than the previous one seen, unless it is
+* the first transaction.  In the first transaction, the server
+* checks instead that the window verifier is one less than the
+* window.
+*/
+.ft CW
+struct authdes_fullname {
+string name<MAXNETNAMELEN>;  /* \fIname of client \f(CW*/
+des_block key;               /* \fIPK encrypted conversation key \f(CW*/
+unsigned int window;         /* \fIencrypted window \f(CW*/
+};
+
+.ft I
+/*
+* A credential is either a fullname or a nickname
+*/
+.ft CW
+union authdes_cred switch (authdes_namekind adc_namekind) {
+	case ADN_FULLNAME:
+		authdes_fullname adc_fullname;
+	case ADN_NICKNAME:
+		unsigned int adc_nickname;
+};
+
+.ft I
+/*
+* A timestamp encodes the time since midnight, January 1, 1970.
+*/
+.ft CW
+struct timestamp {
+	unsigned int seconds;    /* \fIseconds \fP*/
+	unsigned int useconds;   /* \fIand microseconds \fP*/
+};
+
+.ft I
+/*
+* Verifier: client variety
+* The window verifier is only used in the first transaction.  In
+* conjunction with a fullname credential, these items are packed
+* into the following structure before being encrypted:
+*
+* \f(CWstruct {\fP
+*     \f(CWadv_timestamp;            \fP-- one DES block
+*     \f(CWadc_fullname.window;      \fP-- one half DES block
+*     \f(CWadv_winverf;              \fP-- one half DES block
+* \f(CW}\fP
+* This structure is encrypted using CBC mode encryption with an
+* input vector of zero.  All other encryptions of timestamps use
+* ECB mode encryption.
+*/
+.ft CW
+struct authdes_verf_clnt {
+	timestamp adv_timestamp;    /* \fIencrypted timestamp       \fP*/
+	unsigned int adv_winverf;   /* \fIencrypted window verifier \fP*/
+};
+
+.ft I
+/*
+* Verifier: server variety
+* The server returns (encrypted) the same timestamp the client
+* gave it minus one second.  It also tells the client its nickname
+* to be used in future transactions (unencrypted).
+*/
+.ft CW
+struct authdes_verf_svr {
+timestamp adv_timeverf;     /* \fIencrypted verifier      \fP*/
+unsigned int adv_nickname;  /* \fInew nickname for client \fP*/
+};
+.DE
+.KE
+.NH 3
+\&Diffie-Hellman Encryption
+.LP
+In this scheme, there are two constants,
+.I BASE 
+and
+.I MODULUS .
+The
+particular values Sun has chosen for these for the DES
+authentication protocol are:
+.ie t .DS
+.el .DS L
+.ft CW
+const BASE = 3;
+const MODULUS = 
+        "d4a0ba0250b6fd2ec626e7efd637df76c716e22d0944b88b"; /* \fIhex \fP*/
+.DE
+.ft R
+The way this scheme works is best explained by an example.  Suppose
+there are two people "A" and "B" who want to send encrypted
+messages to each other.  So, A and B both generate "secret" keys at
+random which they do not reveal to anyone.  Let these keys be
+represented as SK(A) and SK(B).  They also publish in a public
+directory their "public" keys.  These keys are computed as follows:
+.ie t .DS
+.el .DS L
+.ft CW
+PK(A) = ( BASE ** SK(A) ) mod MODULUS
+PK(B) = ( BASE ** SK(B) ) mod MODULUS
+.DE
+.ft R
+The "**" notation is used here to represent exponentiation.  Now,
+both A and B can arrive at the "common" key between them,
+represented here as CK(A, B), without revealing their secret keys.
+.LP
+A computes:
+.ie t .DS
+.el .DS L
+.ft CW
+CK(A, B) = ( PK(B) ** SK(A)) mod MODULUS
+.DE
+.ft R
+while B computes:
+.ie t .DS
+.el .DS L
+.ft CW
+CK(A, B) = ( PK(A) ** SK(B)) mod MODULUS
+.DE
+.ft R
+These two can be shown to be equivalent:
+.ie t .DS
+.el .DS L
+.ft CW
+(PK(B) ** SK(A)) mod MODULUS = (PK(A) ** SK(B)) mod MODULUS
+.DE
+.ft R
+We drop the "mod MODULUS" parts and assume modulo arithmetic to
+simplify things:
+.ie t .DS
+.el .DS L
+.ft CW
+PK(B) ** SK(A) = PK(A) ** SK(B)
+.DE
+.ft R
+Then, replace PK(B) by what B computed earlier and likewise for
+PK(A).
+.ie t .DS
+.el .DS L
+.ft CW
+((BASE ** SK(B)) ** SK(A) = (BASE ** SK(A)) ** SK(B)
+.DE
+.ft R
+which leads to:
+.ie t .DS
+.el .DS L
+.ft CW
+BASE ** (SK(A) * SK(B)) = BASE ** (SK(A) * SK(B))
+.DE
+.ft R
+This common key CK(A, B) is not used to encrypt the timestamps used
+in the protocol.  Rather, it is used only to encrypt a conversation
+key which is then used to encrypt the timestamps.  The reason for
+doing this is to use the common key as little as possible, for fear
+that it could be broken.  Breaking the conversation key is a far
+less serious offense, since conversations are relatively
+short-lived.
+.LP
+The conversation key is encrypted using 56-bit DES keys, yet the
+common key is 192 bits.  To reduce the number of bits, 56 bits are
+selected from the common key as follows.  The middle-most 8-bytes
+are selected from the common key, and then parity is added to the
+lower order bit of each byte, producing a 56-bit key with 8 bits of
+parity.
+.KS
+.NH 1
+\&Record Marking Standard
+.LP
+When RPC messages are passed on top of a byte stream protocol (like
+TCP/IP), it is necessary, or at least desirable, to delimit one
+message from another in order to detect and possibly recover from
+user protocol errors.  This is called record marking (RM).  Sun uses
+this RM/TCP/IP transport for passing RPC messages on TCP streams.
+One RPC message fits into one RM record.
+.LP
+A record is composed of one or more record fragments.  A record
+fragment is a four-byte header followed by 0 to (2**31) - 1 bytes of
+fragment data.  The bytes encode an unsigned binary number; as with
+XDR integers, the byte order is from highest to lowest.  The number
+encodes two values\(ema boolean which indicates whether the fragment
+is the last fragment of the record (bit value 1 implies the fragment
+is the last fragment) and a 31-bit unsigned binary value which is the
+length in bytes of the fragment's data.  The boolean value is the
+highest-order bit of the header; the length is the 31 low-order bits.
+(Note that this record specification is NOT in XDR standard form!)
+.KE
+.KS
+.NH 1
+\&The RPC Language
+.LP
+Just as there was a need to describe the XDR data-types in a formal
+language, there is also need to describe the procedures that operate
+on these XDR data-types in a formal language as well.  We use the RPC
+Language for this purpose.  It is an extension to the XDR language.
+The following example is used to describe the essence of the
+language.
+.NH 2
+\&An Example Service Described in the RPC Language
+.LP
+Here is an example of the specification of a simple ping program.
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+* Simple ping program
+*/
+.ft CW
+program PING_PROG {
+	/* \fILatest and greatest version\fP */
+	version PING_VERS_PINGBACK {
+	void 
+	PINGPROC_NULL(void) = 0;
+
+.ft I
+	/*
+	* Ping the caller, return the round-trip time
+	* (in microseconds). Returns -1 if the operation
+	* timed out.
+	*/
+.ft CW
+	int
+	PINGPROC_PINGBACK(void) = 1;        
+} = 2;     
+
+.ft I
+/*
+* Original version
+*/
+.ft CW
+version PING_VERS_ORIG {
+	void 
+	PINGPROC_NULL(void) = 0;
+	} = 1;
+} = 1;
+
+const PING_VERS = 2;      /* \fIlatest version \fP*/
+.vs
+.DE
+.KE
+.LP
+The first version described is
+.I PING_VERS_PINGBACK
+with  two procedures,   
+.I PINGPROC_NULL 
+and 
+.I PINGPROC_PINGBACK .
+.I PINGPROC_NULL 
+takes no arguments and returns no results, but it is useful for
+computing round-trip times from the client to the server and back
+again.  By convention, procedure 0 of any RPC protocol should have
+the same semantics, and never require any kind of authentication.
+The second procedure is used for the client to have the server do a
+reverse ping operation back to the client, and it returns the amount
+of time (in microseconds) that the operation used.  The next version,
+.I PING_VERS_ORIG ,
+is the original version of the protocol
+and it does not contain
+.I PINGPROC_PINGBACK
+procedure. It  is useful
+for compatibility  with old client  programs,  and as  this program
+matures it may be dropped from the protocol entirely.
+.KS
+.NH 2
+\&The RPC Language Specification
+.LP
+The  RPC language is identical to  the XDR language, except for the
+added definition of a
+.I program-def 
+described below.
+.DS
+.ft CW
+program-def:
+	"program" identifier "{"
+		version-def 
+		version-def *
+	"}" "=" constant ";"
+
+version-def:
+	"version" identifier "{"
+		procedure-def
+		procedure-def *
+	"}" "=" constant ";"
+
+procedure-def:
+	type-specifier identifier "(" type-specifier ")"
+	"=" constant ";"
+.DE
+.KE
+.NH 2
+\&Syntax Notes
+.IP  1.
+The following keywords  are  added  and   cannot  be used   as
+identifiers: "program" and "version";
+.IP  2.
+A version name cannot occur more than once within the  scope of
+a program definition. Nor can a version number occur more than once
+within the scope of a program definition.
+.IP  3.
+A procedure name cannot occur  more than once within  the scope
+of a version definition. Nor can a procedure number occur more than
+once within the scope of version definition.
+.IP  4.
+Program identifiers are in the same name space as  constant and
+type identifiers.
+.IP  5.
+Only unsigned constants can  be assigned to programs, versions
+and procedures.
+.NH 1
+\&Port Mapper Program Protocol
+.LP
+The port mapper program maps RPC program and version numbers to
+transport-specific port numbers.  This program makes dynamic binding
+of remote programs possible.
+.LP
+This is desirable because the range of reserved port numbers is very
+small and the number of potential remote programs is very large.  By
+running only the port mapper on a reserved port, the port numbers of
+other remote programs can be ascertained by querying the port mapper.
+.LP
+The port mapper also aids in broadcast RPC.  A given RPC program will
+usually have different port number bindings on different machines, so
+there is no way to directly broadcast to all of these programs.  The
+port mapper, however, does have a fixed port number.  So, to
+broadcast to a given program, the client actually sends its message
+to the port mapper located at the broadcast address.  Each port
+mapper that picks up the broadcast then calls the local service
+specified by the client.  When the port mapper gets the reply from
+the local service, it sends the reply on back to the client.
+.KS
+.NH 2
+\&Port Mapper Protocol Specification (in RPC Language)
+.ie t .DS
+.el .DS L
+.ft CW
+.vs 11
+const PMAP_PORT = 111;      /* \fIportmapper port number \fP*/
+
+.ft I
+/*
+* A mapping of (program, version, protocol) to port number
+*/
+.ft CW
+struct mapping {
+	unsigned int prog;
+	unsigned int vers;
+	unsigned int prot;
+	unsigned int port;
+};
+
+.ft I
+/* 
+* Supported values for the "prot" field
+*/
+.ft CW
+const IPPROTO_TCP = 6;      /* \fIprotocol number for TCP/IP \fP*/
+const IPPROTO_UDP = 17;     /* \fIprotocol number for UDP/IP \fP*/
+
+.ft I
+/*
+* A list of mappings
+*/
+.ft CW
+struct *pmaplist {
+	mapping map;
+	pmaplist next;
+};
+.vs
+.DE
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+* Arguments to callit
+*/
+.ft CW
+struct call_args {
+	unsigned int prog;
+	unsigned int vers;
+	unsigned int proc;
+	opaque args<>;
+};  
+
+.ft I
+/*
+* Results of callit
+*/
+.ft CW
+struct call_result {
+	unsigned int port;
+	opaque res<>;
+};
+.vs
+.DE
+.KE
+.ie t .DS
+.el .DS L
+.vs 11
+.ft I
+/*
+* Port mapper procedures
+*/
+.ft CW
+program PMAP_PROG {
+	version PMAP_VERS {
+		void 
+		PMAPPROC_NULL(void)         = 0;
+
+		bool
+		PMAPPROC_SET(mapping)       = 1;
+
+		bool
+		PMAPPROC_UNSET(mapping)     = 2;
+
+		unsigned int
+		PMAPPROC_GETPORT(mapping)   = 3;
+
+		pmaplist
+		PMAPPROC_DUMP(void)         = 4;
+
+		call_result
+		PMAPPROC_CALLIT(call_args)  = 5;
+	} = 2;
+} = 100000;
+.vs
+.DE
+.NH 2
+\&Port Mapper Operation
+.LP
+The portmapper program currently supports two protocols (UDP/IP and
+TCP/IP).  The portmapper is contacted by talking to it on assigned
+port number 111 (SUNRPC [8]) on either of these protocols.  The
+following is a description of each of the portmapper procedures:
+.IP \fBPMAPPROC_NULL:\fP
+This procedure does no work.  By convention, procedure zero of any
+protocol takes no parameters and returns no results.
+.IP \fBPMAPPROC_SET:\fP
+When a program first becomes available on a machine, it registers
+itself with the port mapper program on the same machine.  The program
+passes its program number "prog", version number "vers", transport
+protocol number "prot", and the port "port" on which it awaits
+service request.  The procedure returns a boolean response whose
+value is
+.I TRUE
+if the procedure successfully established the mapping and 
+.I FALSE 
+otherwise.  The procedure refuses to establish
+a mapping if one already exists for the tuple "(prog, vers, prot)".
+.IP \fBPMAPPROC_UNSET:\fP
+When a program becomes unavailable, it should unregister itself with
+the port mapper program on the same machine.  The parameters and
+results have meanings identical to those of
+.I PMAPPROC_SET .
+The protocol and port number fields of the argument are ignored.
+.IP \fBPMAPPROC_GETPORT:\fP
+Given a program number "prog", version number "vers", and transport
+protocol number "prot", this procedure returns the port number on
+which the program is awaiting call requests.  A port value of zeros
+means the program has not been registered.  The "port" field of the
+argument is ignored.
+.IP \fBPMAPPROC_DUMP:\fP
+This procedure enumerates all entries in the port mapper's database.
+The procedure takes no parameters and returns a list of program,
+version, protocol, and port values.
+.IP \fBPMAPPROC_CALLIT:\fP
+This procedure allows a caller to call another remote procedure on
+the same machine without knowing the remote procedure's port number.
+It is intended for supporting broadcasts to arbitrary remote programs
+via the well-known port mapper's port.  The parameters "prog",
+"vers", "proc", and the bytes of "args" are the program number,
+version number, procedure number, and parameters of the remote
+procedure.
+.LP
+.B Note:
+.RS
+.IP  1.
+This procedure only sends a response if the procedure was
+successfully executed and is silent (no response) otherwise.
+.IP  2.
+The port mapper communicates with the remote program using UDP/IP
+only.
+.RE
+.LP
+The procedure returns the remote program's port number, and the bytes
+of results are the results of the remote procedure.
+.bp
+.NH 1
+\&References
+.LP
+[1]  Birrell, Andrew D. & Nelson, Bruce Jay; "Implementing Remote
+Procedure Calls"; XEROX CSL-83-7, October 1983.
+.LP
+[2]  Cheriton, D.; "VMTP:  Versatile Message Transaction Protocol",
+Preliminary Version 0.3; Stanford University, January 1987.
+.LP
+[3]  Diffie & Hellman; "New Directions in Cryptography"; IEEE
+Transactions on Information Theory IT-22, November 1976.
+.LP
+[4]  Harrenstien, K.; "Time Server", RFC 738; Information Sciences
+Institute, October 1977.
+.LP
+[5]  National Bureau of Standards; "Data Encryption Standard"; Federal
+Information Processing Standards Publication 46, January 1977.
+.LP
+[6]  Postel, J.; "Transmission Control Protocol - DARPA Internet
+Program Protocol Specification", RFC 793; Information Sciences
+Institute, September 1981.
+.LP
+[7]  Postel, J.; "User Datagram Protocol", RFC 768; Information Sciences
+Institute, August 1980.
+.LP
+[8]  Reynolds, J.  & Postel, J.; "Assigned Numbers", RFC 923; Information
+Sciences Institute, October 1984.
diff --git a/share/doc/psd/26.rpcrfc/stubs b/share/doc/psd/26.rpcrfc/stubs
new file mode 100644
index 0000000..78b0a2c
--- /dev/null
+++ b/share/doc/psd/26.rpcrfc/stubs
@@ -0,0 +1,3 @@
+.\" $FreeBSD$
+.\"
+.if t .ftr L CR
diff --git a/share/doc/psd/27.nfsrpc/Makefile b/share/doc/psd/27.nfsrpc/Makefile
index 5904787..c9d4f23 100644
--- a/share/doc/psd/27.nfsrpc/Makefile
+++ b/share/doc/psd/27.nfsrpc/Makefile
@@ -4,6 +4,5 @@ VOLUME=		psd/27.nfsrfc
 SRCS=		stubs nfs.rfc.ms
 MACROS=		-ms
 USE_TBL=
-SRCDIR=		${.CURDIR}/../../../../lib/libc/rpc/PSD.doc
 
 .include <bsd.doc.mk>
diff --git a/share/doc/psd/27.nfsrpc/nfs.rfc.ms b/share/doc/psd/27.nfsrpc/nfs.rfc.ms
new file mode 100644
index 0000000..13d7619
--- /dev/null
+++ b/share/doc/psd/27.nfsrpc/nfs.rfc.ms
@@ -0,0 +1,1374 @@
+.\"
+.\" Must use  --  tbl  --  with this one
+.\"
+.\" @(#)nfs.rfc.ms	2.2 88/08/05 4.0 RPCSRC
+.\" $FreeBSD$
+.\"
+.de BT
+.if \\n%=1 .tl ''- % -''
+..
+.ND
+.\" prevent excess underlining in nroff
+.if n .fp 2 R
+.OH 'Network File System: Version 2 Protocol Specification''Page %'
+.EH 'Page %''Network File System: Version 2 Protocol Specification'
+.if \n%=1 .bp
+.SH
+\&Network File System: Version 2 Protocol Specification
+.IX NFS "" "" "" PAGE MAJOR
+.IX "Network File System" "" "" "" PAGE MAJOR
+.IX NFS "version-2 protocol specification"
+.IX "Network File System" "version-2 protocol specification"
+.LP
+.NH 0
+\&Status of this Standard
+.LP
+Note: This document specifies a protocol that Sun Microsystems, Inc.,
+and others are using.  It specifies it in standard ARPA RFC form.
+.NH 1
+\&Introduction
+.IX NFS introduction
+.LP
+The Sun Network Filesystem (NFS) protocol provides transparent remote 
+access to shared filesystems over local area networks.  The NFS 
+protocol is designed to be machine, operating system, network architecture, 
+and transport protocol independent.  This independence is 
+achieved through the use of Remote Procedure Call (RPC) primitives 
+built on top of an External Data Representation (XDR).  Implementations
+exist for a variety of machines, from personal computers to
+supercomputers.
+.LP
+The supporting mount protocol allows the server to hand out remote
+access privileges to a restricted set of clients.  It performs the
+operating system-specific functions that allow, for example, to
+attach remote directory trees to some local file system.
+.NH 2
+\&Remote Procedure Call
+.IX "Remote Procedure Call"
+.LP
+Sun's remote procedure call specification provides a procedure-
+oriented interface to remote services.  Each server supplies a
+program that is a set of procedures.  NFS is one such "program".
+The combination of host address, program number, and procedure
+number specifies one remote service procedure.  RPC does not depend
+on services provided by specific protocols, so it can be used with
+any underlying transport protocol.  See the
+.I "Remote Procedure Calls: Protocol Specification"
+chapter of this manual.
+.NH 2
+\&External Data Representation
+.IX "External Data Representation"
+.LP
+The External Data Representation (XDR) standard provides a common
+way of representing a set of data types over a network.  
+The NFS
+Protocol Specification is written using the RPC data description
+language.  
+For more information, see the
+.I " External Data Representation Standard: Protocol Specification."  
+Sun provides implementations of XDR and
+RPC,  but NFS does not require their use.  Any software that
+provides equivalent functionality can be used, and if the encoding
+is exactly the same it can interoperate with other implementations
+of NFS.
+.NH 2
+\&Stateless Servers
+.IX "stateless servers"
+.IX servers stateless
+.LP
+The NFS protocol is stateless.  That is, a server does not need to
+maintain any extra state information about any of its clients in
+order to function correctly.  Stateless servers have a distinct
+advantage over stateful servers in the event of a failure.  With
+stateless servers, a client need only retry a request until the
+server responds; it does not even need to know that the server has
+crashed, or the network temporarily went down.  The client of a
+stateful server, on the other hand, needs to either detect a server
+crash and rebuild the server's state when it comes back up, or
+cause client operations to fail.
+.LP
+This may not sound like an important issue, but it affects the
+protocol in some unexpected ways.  We feel that it is worth a bit
+of extra complexity in the protocol to be able to write very simple
+servers that do not require fancy crash recovery.
+.LP
+On the other hand, NFS deals with objects such as files and
+directories that inherently have state -- what good would a file be
+if it did not keep its contents intact?  The goal is to not
+introduce any extra state in the protocol itself.  Another way to
+simplify recovery is by making operations "idempotent" whenever
+possible (so that they can potentially be repeated).
+.NH 1
+\&NFS Protocol Definition
+.IX NFS "protocol definition"
+.IX NFS protocol
+.LP
+Servers have been known to change over time, and so can the
+protocol that they use. So RPC provides a version number with each
+RPC request. This RFC describes version two of the NFS protocol.
+Even in the second version, there are various obsolete procedures
+and parameters, which will be removed in later versions. An RFC
+for version three of the NFS protocol is currently under
+preparation.
+.NH 2
+\&File System Model
+.IX filesystem model
+.LP
+NFS assumes a file system that is hierarchical, with directories as
+all but the bottom-level files.  Each entry in a directory (file,
+directory, device, etc.)  has a string name.  Different operating
+systems may have restrictions on the depth of the tree or the names
+used, as well as using different syntax to represent the "pathname",
+which is the concatenation of all the "components" (directory and
+file names) in the name.  A "file system" is a tree on a single
+server (usually a single disk or physical partition) with a specified
+"root".  Some operating systems provide a "mount" operation to make
+all file systems appear as a single tree, while others maintain a
+"forest" of file systems.  Files are unstructured streams of
+uninterpreted bytes.  Version 3 of NFS uses a slightly more general
+file system model.
+.LP
+NFS looks up one component of a pathname at a time.  It may not be
+obvious why it does not just take the whole pathname, traipse down
+the directories, and return a file handle when it is done.  There are
+several good reasons not to do this.  First, pathnames need
+separators between the directory components, and different operating
+systems use different separators.  We could define a Network Standard
+Pathname Representation, but then every pathname would have to be
+parsed and converted at each end.  Other issues are discussed in
+\fINFS Implementation Issues\fP below.
+.LP
+Although files and directories are similar objects in many ways,
+different procedures are used to read directories and files.  This
+provides a network standard format for representing directories.  The
+same argument as above could have been used to justify a procedure
+that returns only one directory entry per call.  The problem is
+efficiency.  Directories can contain many entries, and a remote call
+to return each would be just too slow.
+.NH 2
+\&RPC Information
+.IX NFS "RPC information"
+.IP \fIAuthentication\fP
+The   NFS  service uses 
+.I AUTH_UNIX ,
+.I AUTH_DES ,
+or 
+.I AUTH_SHORT 
+style
+authentication, except in  the  NULL procedure where   
+.I AUTH_NONE 
+is also allowed.
+.IP "\fITransport Protocols\fP"
+NFS currently is supported on UDP/IP only.  
+.IP "\fIPort Number\fP"
+The NFS protocol currently uses the UDP port number 2049.  This is
+not an officially assigned port, so  later versions of the protocol
+use the \*QPortmapping\*U facility of RPC.
+.NH 2
+\&Sizes of XDR Structures
+.IX "XDR structure sizes"
+.LP
+These are the sizes, given in decimal bytes, of various XDR
+structures used in the protocol:
+.DS
+/* \fIThe maximum number of bytes of data in a READ or WRITE request\fP  */
+const MAXDATA = 8192;
+
+/* \fIThe maximum number of bytes in a pathname argument\fP */
+const MAXPATHLEN = 1024;
+
+/* \fIThe maximum number of bytes in a file name argument\fP */
+const MAXNAMLEN = 255;
+
+/* \fIThe size in bytes of the opaque "cookie" passed by READDIR\fP */
+const COOKIESIZE  = 4;
+
+/* \fIThe size in bytes of the opaque file handle\fP */
+const FHSIZE = 32;
+.DE
+.NH 2
+\&Basic Data Types
+.IX "NFS data types"
+.IX NFS "basic data types"
+.LP
+The following XDR  definitions are basic  structures and types used
+in other structures described further on.
+.KS
+.NH 3
+\&stat
+.IX "NFS data types" stat "" \fIstat\fP
+.DS
+enum stat {
+	NFS_OK = 0,
+	NFSERR_PERM=1,
+	NFSERR_NOENT=2,
+	NFSERR_IO=5,
+	NFSERR_NXIO=6,
+	NFSERR_ACCES=13,
+	NFSERR_EXIST=17,
+	NFSERR_NODEV=19,
+	NFSERR_NOTDIR=20,
+	NFSERR_ISDIR=21,
+	NFSERR_FBIG=27,
+	NFSERR_NOSPC=28,
+	NFSERR_ROFS=30,
+	NFSERR_NAMETOOLONG=63,
+	NFSERR_NOTEMPTY=66,
+	NFSERR_DQUOT=69,
+	NFSERR_STALE=70,
+	NFSERR_WFLUSH=99
+};
+.DE
+.KE
+.LP
+The 
+.I stat 
+type  is returned with every  procedure's  results.   A
+value of 
+.I NFS_OK 
+indicates that the  call completed successfully and
+the  results are  valid.  The  other  values indicate  some kind of
+error  occurred on the  server  side  during the servicing   of the
+procedure.  The error values are derived from UNIX error numbers.
+.IP \fBNFSERR_PERM\fP:
+Not owner.  The caller does not have correct ownership
+to perform the requested operation.
+.IP \fBNFSERR_NOENT\fP:
+No such file or directory.    The file or directory
+specified does not exist.
+.IP \fBNFSERR_IO\fP:
+Some sort of hard  error occurred when the operation was
+in progress.  This could be a disk error, for example.
+.IP \fBNFSERR_NXIO\fP:
+No such device or address.
+.IP \fBNFSERR_ACCES\fP:
+Permission  denied.  The  caller does  not  have the
+correct permission to perform the requested operation.
+.IP \fBNFSERR_EXIST\fP:
+File exists.  The file specified already exists.
+.IP \fBNFSERR_NODEV\fP:
+No such device.
+.IP \fBNFSERR_NOTDIR\fP:
+Not   a  directory.    The  caller  specified   a
+non-directory in a directory operation.
+.IP \fBNFSERR_ISDIR\fP:
+Is a directory.  The caller specified  a directory in
+a non- directory operation.
+.IP \fBNFSERR_FBIG\fP:
+File too large.   The  operation caused a file to grow
+beyond the server's limit.
+.IP \fBNFSERR_NOSPC\fP:
+No space left on  device.   The operation caused the
+server's filesystem to reach its limit.
+.IP \fBNFSERR_ROFS\fP:
+Read-only filesystem.  Write attempted on a read-only filesystem.
+.IP \fBNFSERR_NAMETOOLONG\fP:
+File name   too   long.  The file  name  in  an operation was too long.
+.IP \fBNFSERR_NOTEMPTY\fP:
+Directory   not empty.  Attempted  to   remove  a
+directory that was not empty.
+.IP \fBNFSERR_DQUOT\fP:
+Disk quota exceeded.  The client's disk  quota on the
+server has been exceeded.
+.IP \fBNFSERR_STALE\fP:
+The  "fhandle" given in   the arguments was invalid.
+That is, the file referred to by that file handle no longer exists,
+or access to it has been revoked.
+.IP \fBNFSERR_WFLUSH\fP:
+The server's  write cache  used  in the
+.I WRITECACHE 
+call got flushed to disk.
+.LP
+.KS
+.NH 3
+\&ftype
+.IX "NFS data types" ftype "" \fIftype\fP
+.DS
+enum ftype {
+	NFNON = 0,
+	NFREG = 1,
+	NFDIR = 2,
+	NFBLK = 3,
+	NFCHR = 4,
+	NFLNK = 5
+};
+.DE
+.KE
+The enumeration
+.I ftype 
+gives the type of a file.  The type 
+.I NFNON 
+indicates a non-file,
+.I NFREG 
+is a regular file, 
+.I NFDIR 
+is a directory,
+.I NFBLK 
+is a block-special device, 
+.I NFCHR 
+is a character-special device, and
+.I NFLNK 
+is a symbolic link.
+.KS
+.NH 3
+\&fhandle
+.IX "NFS data types" fhandle "" \fIfhandle\fP
+.DS
+typedef opaque fhandle[FHSIZE];
+.DE
+.KE
+The
+.I fhandle 
+is the file handle passed between the server and the client.  
+All file operations are done using file handles to refer to a file or 
+directory.  The file handle can contain whatever information the server
+needs to distinguish an individual file.
+.KS
+.NH 3
+\&timeval
+.IX "NFS data types" timeval "" \fItimeval\fP
+.DS
+struct timeval {
+	unsigned int seconds;
+	unsigned int useconds;
+};
+.DE
+.KE
+The 
+.I timeval
+structure is the number of seconds and microseconds 
+since midnight January 1, 1970, Greenwich Mean Time.  It is used to 
+pass time and date information.
+.KS
+.NH 3
+\&fattr
+.IX "NFS data types" fattr "" \fIfattr\fP
+.DS
+struct fattr {
+	ftype        type;
+	unsigned int mode;
+	unsigned int nlink;
+	unsigned int uid;
+	unsigned int gid;
+	unsigned int size;
+	unsigned int blocksize;
+	unsigned int rdev;
+	unsigned int blocks;
+	unsigned int fsid;
+	unsigned int fileid;
+	timeval      atime;
+	timeval      mtime;
+	timeval      ctime;
+};
+.DE
+.KE
+The
+.I fattr 
+structure contains the attributes of a file; "type" is the type of
+the file; "nlink" is the number of hard links to the file (the number
+of different names for the same file); "uid" is the user
+identification number of the owner of the file; "gid" is the group
+identification number of the group of the file; "size" is the size in
+bytes of the file; "blocksize" is the size in bytes of a block of the
+file; "rdev" is the device number of the file if it is type
+.I NFCHR 
+or
+.I NFBLK ;
+"blocks" is the number of blocks the file takes up on disk; "fsid" is
+the file system identifier for the filesystem containing the file;
+"fileid" is a number that uniquely identifies the file within its
+filesystem; "atime" is the time when the file was last accessed for
+either read or write; "mtime" is the time when the file data was last
+modified (written); and "ctime" is the time when the status of the
+file was last changed.  Writing to the file also changes "ctime" if
+the size of the file changes.
+.LP
+"mode" is the access mode encoded as a set of bits.  Notice that the
+file type is specified both in the mode bits and in the file type.
+This is really a bug in the protocol and will be fixed in future
+versions.  The descriptions given below specify the bit positions
+using octal numbers.
+.TS
+box tab (&) ;
+cfI cfI
+lfL l .
+Bit&Description
+_
+0040000&This is a directory; "type" field should be NFDIR.
+0020000&This is a character special file; "type" field should be NFCHR. 
+0060000&This is a block special file; "type" field should be NFBLK. 
+0100000&This is a regular file; "type" field should be NFREG.
+0120000&This is a symbolic link file;  "type" field should be NFLNK. 
+0140000&This is a named socket; "type" field should be NFNON.
+0004000&Set user id on execution.
+0002000&Set group id on execution.
+0001000&Save swapped text even after use.
+0000400&Read permission for owner.
+0000200&Write permission for owner.
+0000100&Execute and search permission for owner.
+0000040&Read permission for group.
+0000020&Write permission for group.
+0000010&Execute and search permission for group.
+0000004&Read permission for others.
+0000002&Write permission for others.
+0000001&Execute and search permission for others.
+.TE
+.KS
+Notes:
+.IP 
+The bits are  the same as the mode   bits returned  by  the
+.I stat(2) 
+system call in the UNIX system.  The file  type is  specified  both in
+the mode  bits  and in  the file type.   This   is fixed  in future
+versions.
+.IP
+The "rdev" field in the attributes structure is an operating system
+specific device specifier.  It  will be  removed and generalized in
+the next revision of the protocol.
+.KE
+.LP
+.KS
+.NH 3
+\&sattr
+.IX "NFS data types" sattr "" \fIsattr\fP
+.DS
+struct sattr {
+	unsigned int mode;
+	unsigned int uid;
+	unsigned int gid;
+	unsigned int size;
+	timeval      atime;
+	timeval      mtime;
+};
+.DE
+.KE
+The 
+.I sattr
+structure contains the file attributes which can be set
+from the client.  The fields are the same as for  
+.I fattr 
+above.  A "size" of zero  means the file should be  truncated.
+A value of -1 indicates a field that should be ignored.
+.LP
+.KS
+.NH 3
+\&filename
+.IX "NFS data types" filename "" \fIfilename\fP
+.DS
+typedef string filename<MAXNAMLEN>;
+.DE
+.KE
+The type
+.I filename 
+is used for  passing file names  or  pathname components.
+.LP
+.KS
+.NH 3
+\&path
+.IX "NFS data types" path "" \fIpath\fP
+.DS
+typedef string path<MAXPATHLEN>;
+.DE
+.KE
+The type
+.I path 
+is a pathname.  The server considers it as a string
+with no internal structure,  but to the client  it is the name of a
+node in a filesystem tree.
+.LP
+.KS
+.NH 3
+\&attrstat
+.IX "NFS data types" attrstat "" \fIattrstat\fP
+.DS
+union attrstat switch (stat status) {
+	case NFS_OK:
+		fattr attributes;
+	default:
+		void;
+};
+.DE
+.KE
+The 
+.I attrstat 
+structure is a common procedure result.  It contains
+a  "status" and,  if  the call   succeeded,   it also contains  the
+attributes of the file on which the operation was done.
+.LP
+.KS
+.NH 3
+\&diropargs
+.IX "NFS data types" diropargs "" \fIdiropargs\fP
+.DS
+struct diropargs {
+	fhandle  dir;
+	filename name;
+};
+.DE
+.KE
+The  
+.I diropargs 
+structure is used  in  directory  operations.  The
+"fhandle" "dir" is the directory in  which to find the file "name".
+A directory operation is one in which the directory is affected.
+.LP
+.KS
+.NH 3
+\&diropres
+.IX "NFS data types" diropres "" \fIdiropres\fP
+.DS
+union diropres switch (stat status) {
+	case NFS_OK:
+		struct {
+			fhandle file;
+			fattr   attributes;
+		} diropok;
+	default:
+		void;
+};
+.DE
+.KE
+The results of a directory operation  are returned  in a 
+.I diropres 
+structure.  If the call succeeded, a new file handle "file" and the
+"attributes" associated with that file are  returned along with the
+"status".
+.NH 2
+\&Server Procedures
+.IX "NFS server procedures" "" "" "" PAGE MAJOR
+.LP
+The  protocol definition  is given as   a  set  of  procedures with
+arguments  and results defined using the   RPC  language.   A brief
+description of the function of each procedure should provide enough
+information to allow implementation.
+.LP
+All of  the procedures  in   the NFS  protocol  are assumed  to  be
+synchronous.   When a procedure  returns to the  client, the client
+can assume that the operation has completed and any data associated
+with the request is  now on stable storage.  For  example, a client
+.I WRITE 
+request   may  cause  the   server  to  update  data  blocks,
+filesystem information blocks (such as indirect  blocks),  and file
+attribute  information (size  and  modify  times).  When  the 
+.I WRITE 
+returns to the client, it can assume  that the write  is safe, even
+in case of  a server  crash, and  it can discard the  data written.
+This is a very important part  of the statelessness  of the server.
+If the server waited to flush data from remote requests, the client
+would have to  save those requests so that  it could resend them in
+case of a server crash.
+.ie t .DS
+.el .DS L
+
+.ft I
+/*
+* Remote file service routines
+*/
+.ft CW
+program NFS_PROGRAM {
+	version NFS_VERSION {
+		void        NFSPROC_NULL(void)              = 0;
+		attrstat    NFSPROC_GETATTR(fhandle)        = 1;
+		attrstat    NFSPROC_SETATTR(sattrargs)      = 2;
+		void        NFSPROC_ROOT(void)              = 3;
+		diropres    NFSPROC_LOOKUP(diropargs)       = 4;
+		readlinkres NFSPROC_READLINK(fhandle)       = 5;
+		readres     NFSPROC_READ(readargs)          = 6;
+		void        NFSPROC_WRITECACHE(void)        = 7;
+		attrstat    NFSPROC_WRITE(writeargs)        = 8;
+		diropres    NFSPROC_CREATE(createargs)      = 9;
+		stat        NFSPROC_REMOVE(diropargs)       = 10;
+		stat        NFSPROC_RENAME(renameargs)      = 11;
+		stat        NFSPROC_LINK(linkargs)          = 12;
+		stat        NFSPROC_SYMLINK(symlinkargs)    = 13;
+		diropres    NFSPROC_MKDIR(createargs)       = 14;
+		stat        NFSPROC_RMDIR(diropargs)        = 15;
+		readdirres  NFSPROC_READDIR(readdirargs)    = 16;
+		statfsres   NFSPROC_STATFS(fhandle)         = 17;
+	} = 2;
+} = 100003;
+.DE
+.KS
+.NH 3
+\&Do Nothing
+.IX "NFS server procedures" NFSPROC_NULL() "" \fINFSPROC_NULL()\fP
+.DS
+void 
+NFSPROC_NULL(void) = 0;
+.DE
+.KE
+This procedure does no work.   It is made available  in  all RPC
+services to allow server response testing and timing.
+.KS
+.NH 3
+\&Get File Attributes
+.IX "NFS server procedures" NFSPROC_GETATTR() "" \fINFSPROC_GETATTR()\fP
+.DS
+attrstat 
+NFSPROC_GETATTR (fhandle) = 1;
+.DE
+.KE
+If the reply  status is 
+.I NFS_OK ,
+then  the reply attributes contains
+the attributes for the file given by the input fhandle.
+.KS
+.NH 3
+\&Set File Attributes
+.IX "NFS server procedures" NFSPROC_SETATTR() "" \fINFSPROC_SETATTR()\fP
+.DS
+struct sattrargs {
+	fhandle file;
+	sattr attributes;
+	};
+
+attrstat
+NFSPROC_SETATTR (sattrargs) = 2;
+.DE
+.KE
+The  "attributes" argument  contains fields which are either  -1 or
+are  the  new value for  the  attributes of  "file".   If the reply
+status is 
+.I NFS_OK ,
+then the  reply attributes have the attributes of
+the file after the "SETATTR" operation has completed.
+.LP
+Note: The use of -1 to indicate an unused field in "attributes" is
+changed in the next version of the protocol.
+.KS
+.NH 3
+\&Get Filesystem Root
+.IX "NFS server procedures" NFSPROC_ROOT "" \fINFSPROC_ROOT\fP
+.DS
+void 
+NFSPROC_ROOT(void) = 3;
+.DE
+.KE
+Obsolete.  This procedure  is no longer used   because  finding the
+root file handle of a filesystem requires moving  pathnames between
+client  and server.  To  do  this right we would  have  to define a
+network standard representation of pathnames.  Instead, the
+function  of  looking up  the   root  file handle  is  done  by the
+.I MNTPROC_MNT() 
+procedure.    (See the
+.I "Mount Protocol Definition"
+later in this chapter for details).
+.KS
+.NH 3
+\&Look Up File Name
+.IX "NFS server procedures" NFSPROC_LOOKUP() "" \fINFSPROC_LOOKUP()\fP
+.DS
+diropres
+NFSPROC_LOOKUP(diropargs) = 4;
+.DE
+.KE
+If  the reply "status"  is 
+.I NFS_OK ,
+then the reply  "file" and reply
+"attributes" are the file handle and attributes for the file "name"
+in the directory given by "dir" in the argument.
+.KS
+.NH 3
+\&Read From Symbolic Link
+.IX "NFS server procedures" NFSPROC_READLINK() "" \fINFSPROC_READLINK()\fP
+.DS
+union readlinkres switch (stat status) {
+	case NFS_OK:
+		path data;
+	default:
+		void;
+};
+
+readlinkres
+NFSPROC_READLINK(fhandle) = 5;
+.DE
+.KE
+If "status" has the value 
+.I NFS_OK ,
+then the reply "data" is the data in 
+the symbolic link given by the file referred to by the fhandle argument.
+.LP
+Note:  since   NFS always  parses pathnames    on the  client, the
+pathname in  a symbolic  link may  mean something  different (or be
+meaningless) on a different client or on the server if  a different
+pathname syntax is used.
+.KS
+.NH 3
+\&Read From File
+.IX "NFS server procedures" NFSPROC_READ "" \fINFSPROC_READ\fP
+.DS
+struct readargs {
+	fhandle file;
+	unsigned offset;
+	unsigned count;
+	unsigned totalcount;
+};
+
+union readres switch (stat status) {
+	case NFS_OK:
+		fattr attributes;
+		opaque data<NFS_MAXDATA>;
+	default:
+		void;
+};
+
+readres
+NFSPROC_READ(readargs) = 6;
+.DE
+.KE
+Returns  up  to  "count" bytes of   "data" from  the file  given by
+"file", starting at "offset" bytes from  the beginning of the file.
+The first byte of the file is  at offset zero.  The file attributes
+after the read takes place are returned in "attributes".
+.LP
+Note: The  argument "totalcount" is  unused, and is removed in the
+next protocol revision.
+.KS
+.NH 3
+\&Write to Cache
+.IX "NFS server procedures" NFSPROC_WRITECACHE() "" \fINFSPROC_WRITECACHE()\fP
+.DS
+void
+NFSPROC_WRITECACHE(void) = 7;
+.DE
+.KE
+To be used in the next protocol revision.
+.KS
+.NH 3
+\&Write to File
+.IX "NFS server procedures" NFSPROC_WRITE() "" \fINFSPROC_WRITE()\fP
+.DS
+struct writeargs {
+	fhandle file;          
+	unsigned beginoffset;  
+	unsigned offset;       
+	unsigned totalcount;   
+	opaque data<NFS_MAXDATA>;
+};
+
+attrstat	
+NFSPROC_WRITE(writeargs) = 8;
+.DE
+.KE
+Writes   "data" beginning  "offset"  bytes  from the  beginning  of
+"file".  The first byte  of  the file is at  offset  zero.  If  the
+reply "status" is NFS_OK, then  the reply "attributes" contains the
+attributes  of the file after the  write has  completed.  The write
+operation is atomic.  Data from this  call to 
+.I WRITE 
+will not be mixed with data from another client's calls.
+.LP
+Note: The arguments "beginoffset" and "totalcount" are ignored and
+are removed in the next protocol revision.
+.KS
+.NH 3
+\&Create File
+.IX "NFS server procedures" NFSPROC_CREATE() "" \fINFSPROC_CREATE()\fP
+.DS
+struct createargs {
+	diropargs where;
+	sattr attributes;
+};
+
+diropres
+NFSPROC_CREATE(createargs) = 9;
+.DE
+.KE
+The file "name" is created  in the directory given  by "dir".   The
+initial  attributes of the  new file  are given by "attributes".  A
+reply "status"  of NFS_OK indicates that the  file was created, and
+reply "file"   and   reply "attributes"  are    its file handle and
+attributes.   Any  other reply  "status"  means that  the operation
+failed and no file was created.
+.LP
+Note: This  routine should pass  an exclusive create flag, meaning
+"create the file only if it is not already there".
+.KS
+.NH 3
+\&Remove File
+.IX "NFS server procedures" NFSPROC_REMOVE() "" \fINFSPROC_REMOVE()\fP
+.DS
+stat
+NFSPROC_REMOVE(diropargs) = 10;
+.DE
+.KE
+The file "name" is  removed from the directory  given by "dir".   A
+reply of NFS_OK means the directory entry was removed.
+.LP
+Note: possibly non-idempotent operation.
+.KS
+.NH 3
+\&Rename File
+.IX "NFS server procedures" NFSPROC_RENAME() "" \fINFSPROC_RENAME()\fP
+.DS
+struct renameargs {
+	diropargs from;	
+	diropargs to;
+};
+
+stat
+NFSPROC_RENAME(renameargs) = 11;
+.DE
+.KE
+The existing file "from.name" in  the directory given by "from.dir"
+is renamed to "to.name" in the directory given by "to.dir".  If the
+reply  is 
+.I NFS_OK ,
+the file was  renamed.  The  
+RENAME  
+operation is
+atomic on the server; it cannot be interrupted in the middle.
+.LP
+Note: possibly non-idempotent operation.
+.KS
+.NH 3
+\&Create Link to File
+.IX "NFS server procedures" NFSPROC_LINK() "" \fINFSPROC_LINK()\fP
+.DS
+struct linkargs {
+	fhandle from;
+	diropargs to;
+};
+
+stat
+NFSPROC_LINK(linkargs) = 12;
+.DE
+.KE
+Creates the  file "to.name"  in the directory  given   by "to.dir",
+which is a hard link to the existing file given  by "from".  If the
+return value is 
+.I NFS_OK ,
+a link was created.  Any other return value
+indicates an error, and the link was not created.
+.LP
+A hard link should have the property that changes  to either of the
+linked files are reflected in both files.  When a hard link is made
+to a  file, the attributes  for  the file should  have  a value for
+"nlink" that is one greater than the value before the link.
+.LP
+Note: possibly non-idempotent operation.
+.KS
+.NH 3
+\&Create Symbolic Link
+.IX "NFS server procedures" NFSPROC_SYMLINK() "" \fINFSPROC_SYMLINK()\fP
+.DS
+struct symlinkargs {
+	diropargs from;
+	path to;
+	sattr attributes;
+};
+
+stat
+NFSPROC_SYMLINK(symlinkargs) = 13;
+.DE
+.KE
+Creates the  file "from.name" with  ftype  
+.I NFLNK 
+in  the  directory
+given by "from.dir".   The new file contains  the pathname "to" and
+has initial attributes given by "attributes".  If  the return value
+is 
+.I NFS_OK ,
+a link was created.  Any other return value indicates an
+error, and the link was not created.
+.LP
+A symbolic  link is  a pointer to another file.   The name given in
+"to" is  not interpreted by  the server, only stored in  the  newly
+created file.  When the client references a file that is a symbolic
+link, the contents of the symbolic  link are normally transparently
+reinterpreted  as a pathname  to substitute.   A 
+.I READLINK 
+operation returns the data to the client for interpretation.
+.LP
+Note:  On UNIX servers the attributes are never used, since
+symbolic links always have mode 0777.
+.KS
+.NH 3
+\&Create Directory
+.IX "NFS server procedures" NFSPROC_MKDIR() "" \fINFSPROC_MKDIR()\fP
+.DS
+diropres
+NFSPROC_MKDIR (createargs) = 14;
+.DE
+.KE
+The new directory "where.name" is created in the directory given by
+"where.dir".  The initial attributes of the new directory are given
+by "attributes".  A reply "status" of NFS_OK indicates that the new
+directory was created, and reply "file" and  reply "attributes" are
+its file  handle and attributes.  Any  other  reply "status"  means
+that the operation failed and no directory was created.
+.LP
+Note: possibly non-idempotent operation.
+.KS
+.NH 3
+\&Remove Directory
+.IX "NFS server procedures" NFSPROC_RMDIR() "" \fINFSPROC_RMDIR()\fP
+.DS
+stat
+NFSPROC_RMDIR(diropargs) = 15;
+.DE
+.KE
+The existing empty directory "name" in the directory given by "dir"
+is removed.  If the reply is 
+.I NFS_OK ,
+the directory was removed.
+.LP
+Note: possibly non-idempotent operation.
+.KS
+.NH 3
+\&Read From Directory
+.IX "NFS server procedures" NFSPROC_READDIR() "" \fINFSPROC_READDIR()\fP
+.DS
+struct readdirargs {
+	fhandle dir;            
+	nfscookie cookie;
+	unsigned count;         
+};
+
+struct entry {
+	unsigned fileid;
+	filename name;
+	nfscookie cookie;
+	entry *nextentry;
+};
+
+union readdirres switch (stat status) {
+	case NFS_OK:
+		struct {
+			entry *entries;
+			bool eof;
+		} readdirok;
+	default:
+		void;
+};
+
+readdirres
+NFSPROC_READDIR (readdirargs) = 16;
+.DE
+.KE
+Returns a variable number of  directory entries,  with a total size
+of up to "count" bytes, from the directory given  by "dir".  If the
+returned  value of "status"  is 
+.I NFS_OK ,
+then  it  is followed  by a
+variable  number  of "entry"s.    Each "entry" contains  a "fileid"
+which consists of a  unique number  to identify the  file within  a
+filesystem,  the  "name" of the  file, and a "cookie" which   is an
+opaque pointer to the next entry in  the  directory.  The cookie is
+used  in the next  
+.I READDIR 
+call to get more  entries  starting at a
+given point in  the directory.  The  special cookie zero (all  bits
+zero) can be used to get the entries starting  at the  beginning of
+the directory.  The "fileid" field should be the same number as the
+"fileid" in the the  attributes of the  file.  (See the
+.I "Basic Data Types"
+section.) 
+The "eof" flag has a value of
+.I TRUE 
+if there are no more entries in the directory.
+.KS
+.NH 3
+\&Get Filesystem Attributes
+.IX "NFS server procedures" NFSPROC_STATFS() "" \fINFSPROC_STATFS()\fP
+.DS
+union statfsres (stat status) {
+	case NFS_OK:
+		struct {
+			unsigned tsize; 
+			unsigned bsize; 
+			unsigned blocks;
+			unsigned bfree; 
+			unsigned bavail;
+		} info;
+	default:
+		void;
+};
+
+statfsres
+NFSPROC_STATFS(fhandle) = 17;
+.DE
+.KE
+If the  reply "status"  is 
+.I NFS_OK ,
+then the  reply "info" gives the
+attributes for the filesystem that contains file referred to by the
+input fhandle.  The attribute fields contain the following values:
+.IP tsize:   
+The optimum transfer size of the server in bytes.  This is
+the number  of bytes the server  would like to have in the
+data part of READ and WRITE requests.
+.IP bsize:   
+The block size in bytes of the filesystem.
+.IP blocks:  
+The total number of "bsize" blocks on the filesystem.
+.IP bfree:   
+The number of free "bsize" blocks on the filesystem.
+.IP bavail:  
+The number of  "bsize" blocks  available to non-privileged users.
+.LP
+Note: This call does not  work well if a  filesystem has  variable
+size blocks.
+.NH 1
+\&NFS Implementation Issues
+.IX NFS implementation
+.LP
+The NFS protocol is designed to be operating system independent, but
+since this version was designed in a UNIX environment, many
+operations have semantics similar to the operations of the UNIX file
+system.  This section discusses some of the implementation-specific
+semantic issues.
+.NH 2
+\&Server/Client Relationship
+.IX NFS "server/client relationship"
+.LP
+The NFS protocol is designed to allow servers to be as simple and
+general as possible.  Sometimes the simplicity of the server can be a
+problem, if the client wants to implement complicated filesystem
+semantics.
+.LP
+For example, some operating systems allow removal of open files.  A
+process can open a file and, while it is open, remove it from the
+directory.  The file can be read and written as long as the process
+keeps it open, even though the file has no name in the filesystem.
+It is impossible for a stateless server to implement these semantics.
+The client can do some tricks such as renaming the file on remove,
+and only removing it on close.  We believe that the server provides
+enough functionality to implement most file system semantics on the
+client.
+.LP
+Every NFS client can also potentially be a server, and remote and
+local mounted filesystems can be freely intermixed.  This leads to
+some interesting problems when a client travels down the directory
+tree of a remote filesystem and reaches the mount point on the server
+for another remote filesystem.  Allowing the server to follow the
+second remote mount would require loop detection, server lookup, and
+user revalidation.  Instead, we decided not to let clients cross a
+server's mount point.  When a client does a LOOKUP on a directory on
+which the server has mounted a filesystem, the client sees the
+underlying directory instead of the mounted directory.  A client can
+do remote mounts that match the server's mount points to maintain the
+server's view.
+.LP
+.NH 2
+\&Pathname Interpretation
+.IX NFS "pathname interpretation"
+.LP
+There are a few complications to the rule that pathnames are always
+parsed on the client.  For example, symbolic links could have
+different interpretations on different clients.  Another common
+problem for non-UNIX implementations is the special interpretation of
+the pathname ".."  to mean the parent of a given directory.  The next
+revision of the protocol uses an explicit flag to indicate the parent
+instead.
+.NH 2
+\&Permission Issues
+.IX NFS "permission issues"
+.LP
+The NFS protocol, strictly speaking, does not define the permission
+checking used  by servers.  However,  it is  expected that a server
+will do normal operating system permission checking using 
+.I AUTH_UNIX 
+style authentication as the basis of its protection mechanism.  The
+server gets the client's effective "uid", effective "gid", and groups
+on each call and uses them to check permission.  There are various
+problems with this method that can been resolved in interesting ways.
+.LP
+Using "uid" and "gid" implies that the client and server share the
+same "uid" list.  Every server and client pair must have the same
+mapping from user to "uid" and from group to "gid".  Since every
+client can also be a server, this tends to imply that the whole
+network shares the same "uid/gid" space.
+.I AUTH_DES 
+(and the  next
+revision of the NFS protocol) uses string names instead of numbers,
+but there are still complex problems to be solved.
+.LP
+Another problem arises due to the usually stateful open operation.
+Most operating systems check permission at open time, and then check
+that the file is open on each read and write request.  With stateless
+servers, the server has no idea that the file is open and must do
+permission checking on each read and write call.  On a local
+filesystem, a user can open a file and then change the permissions so
+that no one is allowed to touch it, but will still be able to write
+to the file because it is open.  On a remote filesystem, by contrast,
+the write would fail.  To get around this problem, the server's
+permission checking algorithm should allow the owner of a file to
+access it regardless of the permission setting.
+.LP
+A similar problem has to do with paging in from a file over the
+network.  The operating system usually checks for execute permission
+before opening a file for demand paging, and then reads blocks from
+the open file.  The file may not have read permission, but after it
+is opened it doesn't matter.  An NFS server can not tell the
+difference between a normal file read and a demand page-in read.  To
+make this work, the server allows reading of files if the "uid" given
+in the call has execute or read permission on the file.
+.LP
+In most operating systems, a particular user (on the user ID zero)
+has access to all files no matter what permission and ownership they
+have.  This "super-user" permission may not be allowed on the server,
+since anyone who can become super-user on their workstation could
+gain access to all remote files.  The UNIX server by default maps
+user id 0 to -2 before doing its access checking.  This works except
+for NFS root filesystems, where super-user access cannot be avoided.
+.NH 2
+\&Setting RPC Parameters
+.IX NFS "setting RPC parameters"
+.LP
+Various file system parameters and options should be set at mount
+time.  The mount protocol is described in the appendix below.  For
+example, "Soft" mounts as well as "Hard" mounts are usually both
+provided.  Soft mounted file systems return errors when RPC
+operations fail (after a given number of optional retransmissions),
+while hard mounted file systems continue to retransmit forever.
+Clients and servers may need to keep caches of recent operations to
+help avoid problems with non-idempotent operations.
+.NH 1
+\&Mount Protocol Definition
+.IX "mount protocol" "" "" "" PAGE MAJOR
+.sp 1
+.NH 2
+\&Introduction
+.IX "mount protocol" introduction
+.LP
+The mount protocol is separate from, but related to, the NFS
+protocol.  It provides operating system specific services to get the
+NFS off the ground -- looking up server path names, validating user
+identity, and checking access permissions.  Clients use the mount
+protocol to get the first file handle, which allows them entry into a
+remote filesystem.
+.LP
+The mount protocol is kept separate from the NFS protocol to make it
+easy to plug in new access checking and validation methods without
+changing the NFS server protocol.
+.LP
+Notice that the protocol definition implies stateful servers because
+the server maintains a list of client's mount requests.  The mount
+list information is not critical for the correct functioning of
+either the client or the server.  It is intended for advisory use
+only, for example, to warn possible clients when a server is going
+down.
+.LP
+Version one of the mount protocol is used with version two of the NFS
+protocol.  The only connecting point is the
+.I fhandle 
+structure, which is the same for both protocols.
+.NH 2
+\&RPC Information
+.IX "mount protocol"  "RPC information"
+.IP \fIAuthentication\fP
+The mount service uses 
+.I AUTH_UNIX 
+and 
+.I AUTH_DES 
+style authentication only.
+.IP "\fITransport Protocols\fP"
+The mount service is currently supported on UDP/IP only.
+.IP "\fIPort Number\fP"
+Consult the server's portmapper, described in the chapter
+.I "Remote Procedure Calls: Protocol Specification",
+to  find  the  port number on which the mount service is registered.
+.NH 2
+\&Sizes of XDR Structures
+.IX "mount protocol" "XDR structure sizes"
+.LP
+These  are  the sizes,   given  in  decimal   bytes, of various XDR
+structures used in the protocol:
+.DS
+/* \fIThe maximum number of bytes in a pathname argument\fP */
+const MNTPATHLEN = 1024;
+
+/* \fIThe maximum number of bytes in a name argument\fP */
+const MNTNAMLEN = 255;
+
+/* \fIThe size in bytes of the opaque file handle\fP */
+const FHSIZE = 32;
+.DE
+.NH 2
+\&Basic Data Types
+.IX "mount protocol" "basic data types"
+.IX "mount data types"
+.LP
+This section presents the data  types used by  the  mount protocol.
+In many cases they are similar to the types used in NFS.
+.KS
+.NH 3
+\&fhandle
+.IX "mount data types" fhandle "" \fIfhandle\fP
+.DS
+typedef opaque fhandle[FHSIZE];
+.DE
+.KE
+The type 
+.I fhandle 
+is the file handle that the server passes to the
+client.  All file operations are done  using file handles  to refer
+to a  file  or directory.   The  file handle  can  contain whatever
+information the server needs to distinguish an individual file.
+.LP
+This  is the  same as the "fhandle" XDR definition in version 2 of
+the NFS protocol;  see 
+.I "Basic Data Types"
+in the definition of the NFS protocol, above.
+.KS
+.NH 3
+\&fhstatus
+.IX "mount data types" fhstatus "" \fIfhstatus\fP
+.DS
+union fhstatus switch (unsigned status) {
+	case 0:
+		fhandle directory;
+	default:
+		void;
+};
+.DE
+.KE
+The type 
+.I fhstatus 
+is a union.  If a "status" of zero is returned,
+the  call completed   successfully, and  a  file handle   for   the
+"directory"  follows.  A  non-zero  status indicates  some  sort of
+error.  In this case the status is a UNIX error number.
+.KS
+.NH 3
+\&dirpath
+.IX "mount data types" dirpath "" \fIdirpath\fP
+.DS
+typedef string dirpath<MNTPATHLEN>;
+.DE
+.KE
+The type 
+.I dirpath 
+is a server pathname of a directory.
+.KS
+.NH 3
+\&name
+.IX "mount data types" name "" \fIname\fP
+.DS
+typedef string name<MNTNAMLEN>;
+.DE
+.KE
+The type 
+.I name 
+is an arbitrary string used for various names.
+.NH 2
+\&Server Procedures
+.IX "mount server procedures"
+.LP
+The following sections define the RPC procedures  supplied by a
+mount server.
+.ie t .DS
+.el .DS L
+.ft I
+/*
+* Protocol description for the mount program
+*/
+.ft CW
+
+program MOUNTPROG {
+.ft I
+/*
+* Version 1 of the mount protocol used with
+* version 2 of the NFS protocol.
+*/
+.ft CW
+	version MOUNTVERS {
+		void        MOUNTPROC_NULL(void)    = 0;
+		fhstatus    MOUNTPROC_MNT(dirpath)  = 1;
+		mountlist   MOUNTPROC_DUMP(void)    = 2;
+		void        MOUNTPROC_UMNT(dirpath) = 3;
+		void        MOUNTPROC_UMNTALL(void) = 4;
+		exportlist  MOUNTPROC_EXPORT(void)  = 5;
+	} = 1;
+} = 100005;
+.DE
+.KS
+.NH 3
+\&Do Nothing
+.IX "mount server procedures" MNTPROC_NULL() "" \fIMNTPROC_NULL()\fP
+.DS
+void 
+MNTPROC_NULL(void) = 0;
+.DE
+.KE
+This  procedure does no work.  It   is  made  available in all  RPC
+services to allow server response testing and timing.
+.KS
+.NH 3
+\&Add Mount Entry
+.IX "mount server procedures" MNTPROC_MNT() "" \fIMNTPROC_MNT()\fP
+.DS
+fhstatus
+MNTPROC_MNT(dirpath) = 1;
+.DE
+.KE
+If the reply "status" is 0, then the reply "directory" contains the
+file handle for the directory "dirname".  This file handle may be
+used in the NFS protocol.  This procedure also adds a new entry to
+the mount list for this client mounting "dirname".
+.KS
+.NH 3
+\&Return Mount Entries
+.IX "mount server procedures" MNTPROC_DUMP() "" \fIMNTPROC_DUMP()\fP
+.DS
+struct *mountlist {
+	name      hostname;
+	dirpath   directory;
+	mountlist nextentry;
+};
+
+mountlist
+MNTPROC_DUMP(void) = 2;
+.DE
+.KE
+Returns  the list of  remote mounted filesystems.   The "mountlist"
+contains one entry for each "hostname" and "directory" pair.
+.KS
+.NH 3
+\&Remove Mount Entry
+.IX "mount server procedures" MNTPROC_UMNT() "" \fIMNTPROC_UMNT()\fP
+.DS
+void
+MNTPROC_UMNT(dirpath) = 3;
+.DE
+.KE
+Removes the mount list entry for the input "dirpath".
+.KS
+.NH 3
+\&Remove All Mount Entries
+.IX "mount server procedures" MNTPROC_UMNTALL() "" \fIMNTPROC_UMNTALL()\fP
+.DS
+void
+MNTPROC_UMNTALL(void) = 4;
+.DE
+.KE
+Removes all of the mount list entries for this client.
+.KS
+.NH 3
+\&Return Export List
+.IX "mount server procedures" MNTPROC_EXPORT() "" \fIMNTPROC_EXPORT()\fP
+.DS
+struct *groups {
+	name grname;
+	groups grnext;
+};
+
+struct *exportlist {
+	dirpath filesys;
+	groups groups;
+	exportlist next;
+};
+
+exportlist
+MNTPROC_EXPORT(void) = 5;
+.DE
+.KE
+Returns a variable number of export list entries.  Each entry
+contains a filesystem name and a list of groups that are allowed to
+import it.  The filesystem name is in "filesys", and the group name
+is in the list "groups".
+.LP
+Note:  The exportlist should contain
+more information about the status of the filesystem, such as a
+read-only flag.
diff --git a/share/doc/psd/27.nfsrpc/stubs b/share/doc/psd/27.nfsrpc/stubs
new file mode 100644
index 0000000..78b0a2c
--- /dev/null
+++ b/share/doc/psd/27.nfsrpc/stubs
@@ -0,0 +1,3 @@
+.\" $FreeBSD$
+.\"
+.if t .ftr L CR