Update nvi-1.79 to 2.1.1-4334a8297f

This is the gsoc-2011 project to clean up and backport multibyte support
from other nvi forks in a form we can use.

USE_WIDECHAR is on unless building for the rescue crunchgen. This should
allow editing in the native locale encoding.

USE_ICONV depends on make.conf having 'WITH_ICONV=YES' for now.  This
adds the ability to do things like edit a KOI8-R file while having $LANG
set to (say) en_US.UTF-8.  iconv is used to transcode the characters for
display.

Other points:
* It uses gencat and catopen/etc instead of homegrown msg catalog stuff.
* A lot of stuff has been trimmed out, eg: the perl and tcl bindings which
  we could never use in base anyway.
* It uses ncursesw when in widechar mode.  This could be interesting.

GSoC info: http://www.google-melange.com/gsoc/proposal/review/google/gsoc2011/zy/1
Repo at: https://github.com/lichray/nvi2

Obtained from:  Zhihao Yuan <lichray@gmail.com>

14 files changed, 4809 insertions, 0 deletions

diff --git a/contrib/nvi/regex/COPYRIGHT b/contrib/nvi/regex/COPYRIGHT
new file mode 100644
index 0000000..574f6bc
--- /dev/null
+++ b/contrib/nvi/regex/COPYRIGHT
@@ -0,0 +1,56 @@
+Copyright 1992, 1993, 1994 Henry Spencer.  All rights reserved.
+This software is not subject to any license of the American Telephone
+and Telegraph Company or of the Regents of the University of California.
+
+Permission is granted to anyone to use this software for any purpose on
+any computer system, and to alter it and redistribute it, subject
+to the following restrictions:
+
+1. The author is not responsible for the consequences of use of this
+   software, no matter how awful, even if they arise from flaws in it.
+
+2. The origin of this software must not be misrepresented, either by
+   explicit claim or by omission.  Since few users ever read sources,
+   credits must appear in the documentation.
+
+3. Altered versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.  Since few users
+   ever read sources, credits must appear in the documentation.
+
+4. This notice may not be removed or altered.
+
+=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
+/*-
+ * Copyright (c) 1994
+ *	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.
+ *
+ *	@(#)COPYRIGHT	8.1 (Berkeley) 3/16/94
+ */
diff --git a/contrib/nvi/regex/WHATSNEW b/contrib/nvi/regex/WHATSNEW
new file mode 100644
index 0000000..f4301d3
--- /dev/null
+++ b/contrib/nvi/regex/WHATSNEW
@@ -0,0 +1,94 @@
+# @(#)WHATSNEW	8.3 (Berkeley) 3/18/94
+
+New in alpha3.4:  The complex bug alluded to below has been fixed (in a
+slightly kludgey temporary way that may hurt efficiency a bit; this is
+another "get it out the door for 4.4" release).  The tests at the end of
+the tests file have accordingly been uncommented.  The primary sign of
+the bug was that something like a?b matching ab matched b rather than ab.
+(The bug was essentially specific to this exact situation, else it would
+have shown up earlier.)
+
+New in alpha3.3:  The definition of word boundaries has been altered
+slightly, to more closely match the usual programming notion that "_"
+is an alphabetic.  Stuff used for pre-ANSI systems is now in a subdir,
+and the makefile no longer alludes to it in mysterious ways.  The
+makefile has generally been cleaned up some.  Fixes have been made
+(again!) so that the regression test will run without -DREDEBUG, at
+the cost of weaker checking.  A workaround for a bug in some folks'
+<assert.h> has been added.  And some more things have been added to
+tests, including a couple right at the end which are commented out
+because the code currently flunks them (complex bug; fix coming).
+Plus the usual minor cleanup.
+
+New in alpha3.2:  Assorted bits of cleanup and portability improvement
+(the development base is now a BSDI system using GCC instead of an ancient
+Sun system, and the newer compiler exposed some glitches).  Fix for a
+serious bug that affected REs using many [] (including REG_ICASE REs
+because of the way they are implemented), *sometimes*, depending on
+memory-allocation patterns.  The header-file prototypes no longer name
+the parameters, avoiding possible name conflicts.  The possibility that
+some clot has defined CHAR_MIN as (say) `-128' instead of `(-128)' is
+now handled gracefully.  "uchar" is no longer used as an internal type
+name (too many people have the same idea).  Still the same old lousy
+performance, alas.
+
+New in alpha3.1:  Basically nothing, this release is just a bookkeeping
+convenience.  Stay tuned.
+
+New in alpha3.0:  Performance is no better, alas, but some fixes have been
+made and some functionality has been added.  (This is basically the "get
+it out the door in time for 4.4" release.)  One bug fix:  regfree() didn't
+free the main internal structure (how embarrassing).  It is now possible
+to put NULs in either the RE or the target string, using (resp.) a new
+REG_PEND flag and the old REG_STARTEND flag.  The REG_NOSPEC flag to
+regcomp() makes all characters ordinary, so you can match a literal
+string easily (this will become more useful when performance improves!).
+There are now primitives to match beginnings and ends of words, although
+the syntax is disgusting and so is the implementation.  The REG_ATOI
+debugging interface has changed a bit.  And there has been considerable
+internal cleanup of various kinds.
+
+New in alpha2.3:  Split change list out of README, and moved flags notes
+into Makefile.  Macro-ized the name of regex(7) in regex(3), since it has
+to change for 4.4BSD.  Cleanup work in engine.c, and some new regression
+tests to catch tricky cases thereof.
+
+New in alpha2.2:  Out-of-date manpages updated.  Regerror() acquires two
+small extensions -- REG_ITOA and REG_ATOI -- which avoid debugging kludges
+in my own test program and might be useful to others for similar purposes.
+The regression test will now compile (and run) without REDEBUG.  The
+BRE \$ bug is fixed.  Most uses of "uchar" are gone; it's all chars now.
+Char/uchar parameters are now written int/unsigned, to avoid possible
+portability problems with unpromoted parameters.  Some unsigned casts have
+been introduced to minimize portability problems with shifting into sign
+bits.
+
+New in alpha2.1:  Lots of little stuff, cleanup and fixes.  The one big
+thing is that regex.h is now generated, using mkh, rather than being
+supplied in the distribution; due to circularities in dependencies,
+you have to build regex.h explicitly by "make h".  The two known bugs
+have been fixed (and the regression test now checks for them), as has a
+problem with assertions not being suppressed in the absence of REDEBUG.
+No performance work yet.
+
+New in alpha2:  Backslash-anything is an ordinary character, not an
+error (except, of course, for the handful of backslashed metacharacters
+in BREs), which should reduce script breakage.  The regression test
+checks *where* null strings are supposed to match, and has generally
+been tightened up somewhat.  Small bug fixes in parameter passing (not
+harmful, but technically errors) and some other areas.  Debugging
+invoked by defining REDEBUG rather than not defining NDEBUG.
+
+New in alpha+3:  full prototyping for internal routines, using a little
+helper program, mkh, which extracts prototypes given in stylized comments.
+More minor cleanup.  Buglet fix:  it's CHAR_BIT, not CHAR_BITS.  Simple
+pre-screening of input when a literal string is known to be part of the
+RE; this does wonders for performance.
+
+New in alpha+2:  minor bits of cleanup.  Notably, the number "32" for the
+word width isn't hardwired into regexec.c any more, the public header
+file prototypes the functions if __STDC__ is defined, and some small typos
+in the manpages have been fixed.
+
+New in alpha+1:  improvements to the manual pages, and an important
+extension, the REG_STARTEND option to regexec().
diff --git a/contrib/nvi/regex/cclass.h b/contrib/nvi/regex/cclass.h
new file mode 100644
index 0000000..f28bccd
--- /dev/null
+++ b/contrib/nvi/regex/cclass.h
@@ -0,0 +1,85 @@
+/*	$NetBSD: cclass.h,v 1.2 2008/12/05 22:51:42 christos Exp $ */
+
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)cclass.h	8.2 (Berkeley) 3/16/94
+ */
+
+RCHAR_T ALNUM[] = {'a','l','n','u','m',0};
+RCHAR_T ALPHA[] = {'a','l','p','h','a',0};
+RCHAR_T BLANK[] = {'b','l','a','n','k',0};
+RCHAR_T CNTRL[] = {'c','n','t','r','l',0};
+RCHAR_T DIGIT[] = {'d','i','g','i','t',0};
+RCHAR_T GRAPH[] = {'g','r','a','p','h',0};
+RCHAR_T LOWER[] = {'l','o','w','e','r',0};
+RCHAR_T PRINT[] = {'p','r','i','n','t',0};
+RCHAR_T PUNCT[] = {'p','u','n','c','t',0};
+RCHAR_T SPACE[] = {'s','p','a','c','e',0};
+RCHAR_T UPPER[] = {'u','p','p','e','r',0};
+RCHAR_T XDIGIT[] = {'x','d','i','g','i','t',0};
+
+/* character-class table */
+static struct cclass {
+	RCHAR_T *name;
+	const char *chars;
+	const char *multis;
+} cclasses[] = {
+	{ ALNUM,	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\
+0123456789",				"" },
+	{ ALPHA,	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",
+					"" },
+	{ BLANK,	" \t",		"" },
+	{ CNTRL,	"\007\b\t\n\v\f\r\1\2\3\4\5\6\16\17\20\21\22\23\24\
+\25\26\27\30\31\32\33\34\35\36\37\177",	"" },
+	{ DIGIT,	"0123456789",	"" },
+	{ GRAPH,	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\
+0123456789!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
+					"" },
+	{ LOWER,	"abcdefghijklmnopqrstuvwxyz",
+					"" },
+	{ PRINT,	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\
+0123456789!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~ ",
+					"" },
+	{ PUNCT,	"!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
+					"" },
+	{ SPACE,	"\t\n\v\f\r ",	"" },
+	{ UPPER,	"ABCDEFGHIJKLMNOPQRSTUVWXYZ",
+					"" },
+	{ XDIGIT,	"0123456789ABCDEFabcdef",
+					"" },
+	{ NULL,		0,		"" },
+};
diff --git a/contrib/nvi/regex/cname.h b/contrib/nvi/regex/cname.h
new file mode 100644
index 0000000..da69843
--- /dev/null
+++ b/contrib/nvi/regex/cname.h
@@ -0,0 +1,143 @@
+/*	$NetBSD: cname.h,v 1.2 2008/12/05 22:51:42 christos Exp $ */
+
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)cname.h	8.2 (Berkeley) 3/16/94
+ */
+
+/* character-name table */
+static struct cname {
+	const RCHAR_T *name;
+	char code;
+} cnames[] = {
+	{ L("NUL"),		'\0' },
+	{ L("SOH"),		'\001' },
+	{ L("STX"),		'\002' },
+	{ L("ETX"),		'\003' },
+	{ L("EOT"),		'\004' },
+	{ L("ENQ"),		'\005' },
+	{ L("ACK"),		'\006' },
+	{ L("BEL"),		'\007' },
+	{ L("alert"),		'\007' },
+	{ L("BS"),		'\010' },
+	{ L("backspace"),	'\b' },
+	{ L("HT"),		'\011' },
+	{ L("tab"),		'\t' },
+	{ L("LF"),		'\012' },
+	{ L("newline"),		'\n' },
+	{ L("VT"),		'\013' },
+	{ L("vertical-tab"),	'\v' },
+	{ L("FF"),		'\014' },
+	{ L("form-feed"),	'\f' },
+	{ L("CR"),		'\015' },
+	{ L("carriage-return"),	'\r' },
+	{ L("SO"),		'\016' },
+	{ L("SI"),		'\017' },
+	{ L("DLE"),		'\020' },
+	{ L("DC1"),		'\021' },
+	{ L("DC2"),		'\022' },
+	{ L("DC3"),		'\023' },
+	{ L("DC4"),		'\024' },
+	{ L("NAK"),		'\025' },
+	{ L("SYN"),		'\026' },
+	{ L("ETB"),		'\027' },
+	{ L("CAN"),		'\030' },
+	{ L("EM"),		'\031' },
+	{ L("SUB"),		'\032' },
+	{ L("ESC"),		'\033' },
+	{ L("IS4"),		'\034' },
+	{ L("FS"),		'\034' },
+	{ L("IS3"),		'\035' },
+	{ L("GS"),		'\035' },
+	{ L("IS2"),		'\036' },
+	{ L("RS"),		'\036' },
+	{ L("IS1"),		'\037' },
+	{ L("US"),		'\037' },
+	{ L("space"),		' ' },
+	{ L("exclamation-mark"),'!' },
+	{ L("quotation-mark"),	'"' },
+	{ L("number-sign"),	'#' },
+	{ L("dollar-sign"),	'$' },
+	{ L("percent-sign"),	'%' },
+	{ L("ampersand"),	'&' },
+	{ L("apostrophe"),	'\'' },
+	{ L("left-parenthesis"),'(' },
+	{ L("right-parenthesis"),')' },
+	{ L("asterisk"),	'*' },
+	{ L("plus-sign"),	'+' },
+	{ L("comma"),		',' },
+	{ L("hyphen"),		'-' },
+	{ L("hyphen-minus"),	'-' },
+	{ L("period"),		'.' },
+	{ L("full-stop"),	'.' },
+	{ L("slash"),		'/' },
+	{ L("solidus"),		'/' },
+	{ L("zero"),		'0' },
+	{ L("one"),		'1' },
+	{ L("two"),		'2' },
+	{ L("three"),		'3' },
+	{ L("four"),		'4' },
+	{ L("five"),		'5' },
+	{ L("six"),		'6' },
+	{ L("seven"),		'7' },
+	{ L("eight"),		'8' },
+	{ L("nine"),		'9' },
+	{ L("colon"),		':' },
+	{ L("semicolon"),	';' },
+	{ L("less-than-sign"),	'<' },
+	{ L("equals-sign"),	'=' },
+	{ L("greater-than-sign"),'>' },
+	{ L("question-mark"),	'?' },
+	{ L("commercial-at"),	'@' },
+	{ L("left-square-bracket"),'[' },
+	{ L("backslash"),	'\\' },
+	{ L("reverse-solidus"),	'\\' },
+	{ L("right-square-bracket"),']' },
+	{ L("circumflex"),	'^' },
+	{ L("circumflex-accent"),'^' },
+	{ L("underscore"),	'_' },
+	{ L("low-line"),	'_' },
+	{ L("grave-accent"),	'`' },
+	{ L("left-brace"),	'{' },
+	{ L("left-curly-bracket"),'{' },
+	{ L("vertical-line"),	'|' },
+	{ L("right-brace"),	'}' },
+	{ L("right-curly-bracket"),'}' },
+	{ L("tilde"),		'~' },
+	{ L("DEL"),		'\177' },
+	{ NULL,			0 },
+};
diff --git a/contrib/nvi/regex/engine.c b/contrib/nvi/regex/engine.c
new file mode 100644
index 0000000..ad1c501
--- /dev/null
+++ b/contrib/nvi/regex/engine.c
@@ -0,0 +1,1102 @@
+/*	$NetBSD: engine.c,v 1.7 2011/11/19 17:45:11 tnozaki Exp $ */
+
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)engine.c	8.4 (Berkeley) 3/19/94
+ */
+
+/*
+ * The matching engine and friends.  This file is #included by regexec.c
+ * after suitable #defines of a variety of macros used herein, so that
+ * different state representations can be used without duplicating masses
+ * of code.
+ */
+
+#ifdef SNAMES
+#define	matcher	smatcher
+#define	fast	sfast
+#define	slow	sslow
+#define	dissect	sdissect
+#define	backref	sbackref
+#define	step	sstep
+#define	print	sprint
+#define	at	sat
+#define	match	smat
+#endif
+#ifdef LNAMES
+#define	matcher	lmatcher
+#define	fast	lfast
+#define	slow	lslow
+#define	dissect	ldissect
+#define	backref	lbackref
+#define	step	lstep
+#define	print	lprint
+#define	at	lat
+#define	match	lmat
+#endif
+
+/* another structure passed up and down to avoid zillions of parameters */
+struct match {
+	struct re_guts *g;
+	int eflags;
+	regmatch_t *pmatch;	/* [nsub+1] (0 element unused) */
+	const RCHAR_T *offp;		/* offsets work from here */
+	const RCHAR_T *beginp;		/* start of string -- virtual NUL precedes */
+	const RCHAR_T *endp;		/* end of string -- virtual NUL here */
+	const RCHAR_T *coldp;		/* can be no match starting before here */
+	const RCHAR_T **lastpos;	/* [nplus+1] */
+	STATEVARS;
+	states st;		/* current states */
+	states fresh;		/* states for a fresh start */
+	states tmp;		/* temporary */
+	states empty;		/* empty set of states */
+};
+
+/* ========= begin header generated by ./mkh ========= */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* === engine.c === */
+static int matcher __P((struct re_guts *g, const RCHAR_T *string, size_t nmatch, regmatch_t pmatch[], int eflags));
+static const RCHAR_T *dissect __P((struct match *m, const RCHAR_T *start, const RCHAR_T *stop, sopno startst, sopno stopst));
+static const RCHAR_T *backref __P((struct match *m, const RCHAR_T *start, const RCHAR_T *stop, sopno startst, sopno stopst, sopno lev));
+static const RCHAR_T *fast __P((struct match *m, const RCHAR_T *start, const RCHAR_T *stop, sopno startst, sopno stopst));
+static const RCHAR_T *slow __P((struct match *m, const RCHAR_T *start, const RCHAR_T *stop, sopno startst, sopno stopst));
+static states step __P((struct re_guts *g, sopno start, sopno stop, states bef, int flag, RCHAR_T ch, states aft));
+#define	BOL	(1)
+#define	EOL	(BOL+1)
+#define	BOLEOL	(BOL+2)
+#define	NOTHING	(BOL+3)
+#define	BOW	(BOL+4)
+#define	EOW	(BOL+5)
+#ifdef REDEBUG
+static void print __P((struct match *m, char *caption, states st, int ch, FILE *d));
+#endif
+#ifdef REDEBUG
+static void at __P((struct match *m, char *title, char *start, char *stop, sopno startst, sopno stopst));
+#endif
+#ifdef REDEBUG
+static char *pchar __P((int ch));
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+/* ========= end header generated by ./mkh ========= */
+
+#ifdef REDEBUG
+#define	SP(t, s, c)	print(m, t, s, c, stdout)
+#define	AT(t, p1, p2, s1, s2)	at(m, t, p1, p2, s1, s2)
+#define	NOTE(str)	{ if (m->eflags&REG_TRACE) printf("=%s\n", (str)); }
+#else
+#define	SP(t, s, c)	/* nothing */
+#define	AT(t, p1, p2, s1, s2)	/* nothing */
+#define	NOTE(s)	/* nothing */
+#endif
+
+/*
+ - matcher - the actual matching engine
+ == static int matcher(register struct re_guts *g, const RCHAR_T *string, \
+ ==	size_t nmatch, regmatch_t pmatch[], int eflags);
+ */
+static int			/* 0 success, REG_NOMATCH failure */
+matcher(g, string, nmatch, pmatch, eflags)
+register struct re_guts *g;
+const RCHAR_T *string;
+size_t nmatch;
+regmatch_t pmatch[];
+int eflags;
+{
+	register const RCHAR_T *endp;
+	register size_t i;
+	struct match mv;
+	register struct match *m = &mv;
+	register const RCHAR_T *dp;
+	register const sopno gf = g->firststate+1;	/* +1 for OEND */
+	register const sopno gl = g->laststate;
+	const RCHAR_T *start;
+	const RCHAR_T *stop;
+
+	/* simplify the situation where possible */
+	if (g->cflags&REG_NOSUB)
+		nmatch = 0;
+	if (eflags&REG_STARTEND) {
+		start = string + pmatch[0].rm_so;
+		stop = string + pmatch[0].rm_eo;
+	} else {
+		start = string;
+		stop = start + STRLEN(start);
+	}
+	if (stop < start)
+		return(REG_INVARG);
+
+	/* prescreening; this does wonders for this rather slow code */
+	if (g->must != NULL) {
+		for (dp = start; dp < stop; dp++)
+			if (*dp == g->must[0] && (size_t)(stop - dp) >= g->mlen &&
+				MEMCMP(dp, g->must, g->mlen) == 0)
+				break;
+		if (dp == stop)		/* we didn't find g->must */
+			return(REG_NOMATCH);
+	}
+
+	/* match struct setup */
+	m->g = g;
+	m->eflags = eflags;
+	m->pmatch = NULL;
+	m->lastpos = NULL;
+	m->offp = string;
+	m->beginp = start;
+	m->endp = stop;
+	STATESETUP(m, 4);
+	SETUP(m->st);
+	SETUP(m->fresh);
+	SETUP(m->tmp);
+	SETUP(m->empty);
+	CLEAR(m->empty);
+
+	/* this loop does only one repetition except for backrefs */
+	for (;;) {
+		endp = fast(m, start, stop, gf, gl);
+		if (endp == NULL) {		/* a miss */
+			STATETEARDOWN(m);
+			return(REG_NOMATCH);
+		}
+		if (nmatch == 0 && !g->backrefs)
+			break;		/* no further info needed */
+
+		/* where? */
+		assert(m->coldp != NULL);
+		for (;;) {
+			NOTE("finding start");
+			endp = slow(m, m->coldp, stop, gf, gl);
+			if (endp != NULL)
+				break;
+			assert(m->coldp < m->endp);
+			m->coldp++;
+		}
+		if (nmatch == 1 && !g->backrefs)
+			break;		/* no further info needed */
+
+		/* oh my, he wants the subexpressions... */
+		if (m->pmatch == NULL)
+			m->pmatch = (regmatch_t *)malloc((m->g->nsub + 1) *
+							sizeof(regmatch_t));
+		if (m->pmatch == NULL) {
+			STATETEARDOWN(m);
+			return(REG_ESPACE);
+		}
+		for (i = 1; i <= m->g->nsub; i++)
+			m->pmatch[i].rm_so = m->pmatch[i].rm_eo = -1;
+		if (!g->backrefs && !(m->eflags&REG_BACKR)) {
+			NOTE("dissecting");
+			dp = dissect(m, m->coldp, endp, gf, gl);
+		} else {
+			if (g->nplus > 0 && m->lastpos == NULL)
+				m->lastpos = (const RCHAR_T **)malloc((g->nplus+1) *
+							sizeof(const RCHAR_T *));
+			if (g->nplus > 0 && m->lastpos == NULL) {
+				free(m->pmatch);
+				STATETEARDOWN(m);
+				return(REG_ESPACE);
+			}
+			NOTE("backref dissect");
+			dp = backref(m, m->coldp, endp, gf, gl, (sopno)0);
+		}
+		if (dp != NULL)
+			break;
+
+		/* uh-oh... we couldn't find a subexpression-level match */
+		assert(g->backrefs);	/* must be back references doing it */
+		assert(g->nplus == 0 || m->lastpos != NULL);
+		for (;;) {
+			if (dp != NULL || endp <= m->coldp)
+				break;		/* defeat */
+			NOTE("backoff");
+			endp = slow(m, m->coldp, endp-1, gf, gl);
+			if (endp == NULL)
+				break;		/* defeat */
+			/* try it on a shorter possibility */
+#ifndef NDEBUG
+			for (i = 1; i <= m->g->nsub; i++) {
+				assert(m->pmatch[i].rm_so == -1);
+				assert(m->pmatch[i].rm_eo == -1);
+			}
+#endif
+			NOTE("backoff dissect");
+			dp = backref(m, m->coldp, endp, gf, gl, (sopno)0);
+		}
+		assert(dp == NULL || dp == endp);
+		if (dp != NULL)		/* found a shorter one */
+			break;
+
+		/* despite initial appearances, there is no match here */
+		NOTE("false alarm");
+		start = m->coldp + 1;	/* recycle starting later */
+		assert(start <= stop);
+	}
+
+	/* fill in the details if requested */
+	if (nmatch > 0) {
+		pmatch[0].rm_so = m->coldp - m->offp;
+		pmatch[0].rm_eo = endp - m->offp;
+	}
+	if (nmatch > 1) {
+		assert(m->pmatch != NULL);
+		for (i = 1; i < nmatch; i++)
+			if (i <= m->g->nsub)
+				pmatch[i] = m->pmatch[i];
+			else {
+				pmatch[i].rm_so = -1;
+				pmatch[i].rm_eo = -1;
+			}
+	}
+
+	if (m->pmatch != NULL)
+		free((char *)m->pmatch);
+	if (m->lastpos != NULL)
+		free((char *)m->lastpos);
+	STATETEARDOWN(m);
+	return(0);
+}
+
+/*
+ - dissect - figure out what matched what, no back references
+ == static const RCHAR_T *dissect(register struct match *m, const RCHAR_T *start, \
+ ==	const RCHAR_T *stop, sopno startst, sopno stopst);
+ */
+static const RCHAR_T *			/* == stop (success) always */
+dissect(m, start, stop, startst, stopst)
+register struct match *m;
+const RCHAR_T *start;
+const RCHAR_T *stop;
+sopno startst;
+sopno stopst;
+{
+	register int i;
+	register sopno ss;	/* start sop of current subRE */
+	register sopno es;	/* end sop of current subRE */
+	register const RCHAR_T *sp;	/* start of string matched by it */
+	register const RCHAR_T *stp;	/* string matched by it cannot pass here */
+	register const RCHAR_T *rest;	/* start of rest of string */
+	register const RCHAR_T *tail;	/* string unmatched by rest of RE */
+	register sopno ssub;	/* start sop of subsubRE */
+	register sopno esub;	/* end sop of subsubRE */
+	register const RCHAR_T *ssp;	/* start of string matched by subsubRE */
+	register const RCHAR_T *sep;	/* end of string matched by subsubRE */
+	register const RCHAR_T *oldssp;	/* previous ssp */
+	register const RCHAR_T *dp;
+
+	AT("diss", start, stop, startst, stopst);
+	sp = start;
+	for (ss = startst; ss < stopst; ss = es) {
+		/* identify end of subRE */
+		es = ss;
+		switch (m->g->strip[es]) {
+		case OPLUS_:
+		case OQUEST_:
+			es += m->g->stripdata[es];
+			break;
+		case OCH_:
+			while (m->g->strip[es] != O_CH)
+				es += m->g->stripdata[es];
+			break;
+		}
+		es++;
+
+		/* figure out what it matched */
+		switch (m->g->strip[ss]) {
+		case OEND:
+			assert(nope);
+			break;
+		case OCHAR:
+			sp++;
+			break;
+		case OBOL:
+		case OEOL:
+		case OBOW:
+		case OEOW:
+			break;
+		case OANY:
+		case OANYOF:
+			sp++;
+			break;
+		case OBACK_:
+		case O_BACK:
+			assert(nope);
+			break;
+		/* cases where length of match is hard to find */
+		case OQUEST_:
+			stp = stop;
+			for (;;) {
+				/* how long could this one be? */
+				rest = slow(m, sp, stp, ss, es);
+				assert(rest != NULL);	/* it did match */
+				/* could the rest match the rest? */
+				tail = slow(m, rest, stop, es, stopst);
+				if (tail == stop)
+					break;		/* yes! */
+				/* no -- try a shorter match for this one */
+				stp = rest - 1;
+				assert(stp >= sp);	/* it did work */
+			}
+			ssub = ss + 1;
+			esub = es - 1;
+			/* did innards match? */
+			if (slow(m, sp, rest, ssub, esub) != NULL) {
+				dp = dissect(m, sp, rest, ssub, esub);
+				assert(dp == rest);
+			} else		/* no */
+				assert(sp == rest);
+			sp = rest;
+			break;
+		case OPLUS_:
+			stp = stop;
+			for (;;) {
+				/* how long could this one be? */
+				rest = slow(m, sp, stp, ss, es);
+				assert(rest != NULL);	/* it did match */
+				/* could the rest match the rest? */
+				tail = slow(m, rest, stop, es, stopst);
+				if (tail == stop)
+					break;		/* yes! */
+				/* no -- try a shorter match for this one */
+				stp = rest - 1;
+				assert(stp >= sp);	/* it did work */
+			}
+			ssub = ss + 1;
+			esub = es - 1;
+			ssp = sp;
+			oldssp = ssp;
+			for (;;) {	/* find last match of innards */
+				sep = slow(m, ssp, rest, ssub, esub);
+				if (sep == NULL || sep == ssp)
+					break;	/* failed or matched null */
+				oldssp = ssp;	/* on to next try */
+				ssp = sep;
+			}
+			if (sep == NULL) {
+				/* last successful match */
+				sep = ssp;
+				ssp = oldssp;
+			}
+			assert(sep == rest);	/* must exhaust substring */
+			assert(slow(m, ssp, sep, ssub, esub) == rest);
+			dp = dissect(m, ssp, sep, ssub, esub);
+			assert(dp == sep);
+			sp = rest;
+			break;
+		case OCH_:
+			stp = stop;
+			for (;;) {
+				/* how long could this one be? */
+				rest = slow(m, sp, stp, ss, es);
+				assert(rest != NULL);	/* it did match */
+				/* could the rest match the rest? */
+				tail = slow(m, rest, stop, es, stopst);
+				if (tail == stop)
+					break;		/* yes! */
+				/* no -- try a shorter match for this one */
+				stp = rest - 1;
+				assert(stp >= sp);	/* it did work */
+			}
+			ssub = ss + 1;
+			esub = ss + m->g->stripdata[ss] - 1;
+			assert(m->g->strip[esub] == OOR1);
+			for (;;) {	/* find first matching branch */
+				if (slow(m, sp, rest, ssub, esub) == rest)
+					break;	/* it matched all of it */
+				/* that one missed, try next one */
+				assert(m->g->strip[esub] == OOR1);
+				esub++;
+				assert(m->g->strip[esub] == OOR2);
+				ssub = esub + 1;
+				esub += m->g->stripdata[esub];
+				if (m->g->strip[esub] == OOR2)
+					esub--;
+				else
+					assert(m->g->strip[esub] == O_CH);
+			}
+			dp = dissect(m, sp, rest, ssub, esub);
+			assert(dp == rest);
+			sp = rest;
+			break;
+		case O_PLUS:
+		case O_QUEST:
+		case OOR1:
+		case OOR2:
+		case O_CH:
+			assert(nope);
+			break;
+		case OLPAREN:
+			i = m->g->stripdata[ss];
+			assert(0 < i && i <= m->g->nsub);
+			m->pmatch[i].rm_so = sp - m->offp;
+			break;
+		case ORPAREN:
+			i = m->g->stripdata[ss];
+			assert(0 < i && i <= m->g->nsub);
+			m->pmatch[i].rm_eo = sp - m->offp;
+			break;
+		default:		/* uh oh */
+			assert(nope);
+			break;
+		}
+	}
+
+	assert(sp == stop);
+	return(sp);
+}
+
+/*
+ - backref - figure out what matched what, figuring in back references
+ == static const RCHAR_T *backref(register struct match *m, const RCHAR_T *start, \
+ ==	const RCHAR_T *stop, sopno startst, sopno stopst, sopno lev);
+ */
+static const RCHAR_T *			/* == stop (success) or NULL (failure) */
+backref(m, start, stop, startst, stopst, lev)
+register struct match *m;
+const RCHAR_T *start;
+const RCHAR_T *stop;
+sopno startst;
+sopno stopst;
+sopno lev;			/* PLUS nesting level */
+{
+	register int i;
+	register sopno ss;	/* start sop of current subRE */
+	register const RCHAR_T *sp;	/* start of string matched by it */
+	register sopno ssub;	/* start sop of subsubRE */
+	register sopno esub;	/* end sop of subsubRE */
+	register const RCHAR_T *ssp;	/* start of string matched by subsubRE */
+	register const RCHAR_T *dp;
+	register size_t len;
+	register int hard;
+	register sop s;
+	register RCHAR_T d;
+	register regoff_t offsave;
+	register cset *cs;
+
+	AT("back", start, stop, startst, stopst);
+	sp = start;
+
+	/* get as far as we can with easy stuff */
+	hard = 0;
+	for (ss = startst; !hard && ss < stopst; ss++) {
+		s = m->g->strip[ss];
+		d = m->g->stripdata[ss];
+		switch (s) {
+		case OCHAR:
+			if (sp == stop || *sp++ != d)
+				return(NULL);
+			break;
+		case OANY:
+			if (sp == stop)
+				return(NULL);
+			sp++;
+			break;
+		case OANYOF:
+			cs = &m->g->sets[d];
+			if (sp == stop || !CHIN(cs, *sp++))
+				return(NULL);
+			break;
+		case OBOL:
+			if ( (sp == m->beginp && !(m->eflags&REG_NOTBOL)) ||
+					(sp < m->endp && *(sp-1) == '\n' &&
+						(m->g->cflags&REG_NEWLINE)) )
+				{ /* yes */ }
+			else
+				return(NULL);
+			break;
+		case OEOL:
+			if ( (sp == m->endp && !(m->eflags&REG_NOTEOL)) ||
+					(sp < m->endp && *sp == '\n' &&
+						(m->g->cflags&REG_NEWLINE)) )
+				{ /* yes */ }
+			else
+				return(NULL);
+			break;
+		case OBOW:
+			if (( (sp == m->beginp && !(m->eflags&REG_NOTBOL)) ||
+					(sp < m->endp && *(sp-1) == '\n' &&
+						(m->g->cflags&REG_NEWLINE)) ||
+					(sp > m->beginp &&
+							!ISWORD(*(sp-1))) ) &&
+					(sp < m->endp && ISWORD(*sp)) )
+				{ /* yes */ }
+			else
+				return(NULL);
+			break;
+		case OEOW:
+			if (( (sp == m->endp && !(m->eflags&REG_NOTEOL)) ||
+					(sp < m->endp && *sp == '\n' &&
+						(m->g->cflags&REG_NEWLINE)) ||
+					(sp < m->endp && !ISWORD(*sp)) ) &&
+					(sp > m->beginp && ISWORD(*(sp-1))) )
+				{ /* yes */ }
+			else
+				return(NULL);
+			break;
+		case O_QUEST:
+			break;
+		case OOR1:	/* matches null but needs to skip */
+			ss++;
+			s = m->g->strip[ss];
+			d = m->g->stripdata[ss];
+			do {
+				assert(s == OOR2);
+				ss += d;
+				s = m->g->strip[ss];
+				d = m->g->stripdata[ss];
+			} while (s != O_CH);
+			/* note that the ss++ gets us past the O_CH */
+			break;
+		default:	/* have to make a choice */
+			hard = 1;
+			break;
+		}
+	}
+	if (!hard) {		/* that was it! */
+		if (sp != stop)
+			return(NULL);
+		return(sp);
+	}
+	ss--;			/* adjust for the for's final increment */
+
+	/* the hard stuff */
+	AT("hard", sp, stop, ss, stopst);
+	s = m->g->strip[ss];
+	d = m->g->stripdata[ss];
+	switch (s) {
+	case OBACK_:		/* the vilest depths */
+		i = d;
+		assert(0 < i && i <= m->g->nsub);
+		if (m->pmatch[i].rm_eo == -1)
+			return(NULL);
+		assert(m->pmatch[i].rm_so != -1);
+		len = m->pmatch[i].rm_eo - m->pmatch[i].rm_so;
+		assert(stop - m->beginp >= len);
+		if (sp > stop - len)
+			return(NULL);	/* not enough left to match */
+		ssp = m->offp + m->pmatch[i].rm_so;
+		if (memcmp(sp, ssp, len) != 0)
+			return(NULL);
+		while (m->g->strip[ss] != O_BACK || m->g->stripdata[ss] != i)
+			ss++;
+		return(backref(m, sp+len, stop, ss+1, stopst, lev));
+		break;
+	case OQUEST_:		/* to null or not */
+		dp = backref(m, sp, stop, ss+1, stopst, lev);
+		if (dp != NULL)
+			return(dp);	/* not */
+		return(backref(m, sp, stop, ss+d+1, stopst, lev));
+		break;
+	case OPLUS_:
+		assert(m->lastpos != NULL);
+		assert(lev+1 <= m->g->nplus);
+		m->lastpos[lev+1] = sp;
+		return(backref(m, sp, stop, ss+1, stopst, lev+1));
+		break;
+	case O_PLUS:
+		if (sp == m->lastpos[lev])	/* last pass matched null */
+			return(backref(m, sp, stop, ss+1, stopst, lev-1));
+		/* try another pass */
+		m->lastpos[lev] = sp;
+		dp = backref(m, sp, stop, ss-d+1, stopst, lev);
+		if (dp == NULL)
+			return(backref(m, sp, stop, ss+1, stopst, lev-1));
+		else
+			return(dp);
+		break;
+	case OCH_:		/* find the right one, if any */
+		ssub = ss + 1;
+		esub = ss + d - 1;
+		assert(m->g->strip[esub] == OOR1);
+		for (;;) {	/* find first matching branch */
+			dp = backref(m, sp, stop, ssub, esub, lev);
+			if (dp != NULL)
+				return(dp);
+			/* that one missed, try next one */
+			if (m->g->strip[esub] == O_CH)
+				return(NULL);	/* there is none */
+			esub++;
+			assert(m->g->strip[esub] == OOR2);
+			ssub = esub + 1;
+			esub += m->g->stripdata[esub];
+			if (m->g->strip[esub] == OOR2)
+				esub--;
+			else
+				assert(m->g->strip[esub] == O_CH);
+		}
+		break;
+	case OLPAREN:		/* must undo assignment if rest fails */
+		i = d;
+		assert(0 < i && i <= m->g->nsub);
+		offsave = m->pmatch[i].rm_so;
+		m->pmatch[i].rm_so = sp - m->offp;
+		dp = backref(m, sp, stop, ss+1, stopst, lev);
+		if (dp != NULL)
+			return(dp);
+		m->pmatch[i].rm_so = offsave;
+		return(NULL);
+		break;
+	case ORPAREN:		/* must undo assignment if rest fails */
+		i = d;
+		assert(0 < i && i <= m->g->nsub);
+		offsave = m->pmatch[i].rm_eo;
+		m->pmatch[i].rm_eo = sp - m->offp;
+		dp = backref(m, sp, stop, ss+1, stopst, lev);
+		if (dp != NULL)
+			return(dp);
+		m->pmatch[i].rm_eo = offsave;
+		return(NULL);
+		break;
+	default:		/* uh oh */
+		assert(nope);
+		break;
+	}
+
+	/* "can't happen" */
+	assert(nope);
+	/* NOTREACHED */
+	return NULL;
+}
+
+/*
+ - fast - step through the string at top speed
+ == static const RCHAR_T *fast(register struct match *m, const RCHAR_T *start, \
+ ==	const RCHAR_T *stop, sopno startst, sopno stopst);
+ */
+static const RCHAR_T *			/* where tentative match ended, or NULL */
+fast(m, start, stop, startst, stopst)
+register struct match *m;
+const RCHAR_T *start;
+const RCHAR_T *stop;
+sopno startst;
+sopno stopst;
+{
+	register states st = m->st;
+	register states fresh = m->fresh;
+	register states tmp = m->tmp;
+	register const RCHAR_T *p = start;
+	register RCHAR_T c = (start == m->beginp) ? OUT : *(start-1);
+	register RCHAR_T lastc;	/* previous c */
+	register int flag;
+	register int i;
+	register const RCHAR_T *coldp;	/* last p after which no match was underway */
+
+	CLEAR(st);
+	SET1(st, startst);
+	st = step(m->g, startst, stopst, st, NOTHING, OUT, st);
+	ASSIGN(fresh, st);
+	SP("start", st, *p);
+	coldp = NULL;
+	for (;;) {
+		/* next character */
+		lastc = c;
+		c = (p == m->endp) ? OUT : *p;
+		if (EQ(st, fresh))
+			coldp = p;
+
+		/* is there an EOL and/or BOL between lastc and c? */
+		flag = 0;
+		i = 0;
+		if ( (lastc == '\n' && m->g->cflags&REG_NEWLINE) ||
+				(lastc == OUT && !(m->eflags&REG_NOTBOL)) ) {
+			flag = BOL;
+			i = m->g->nbol;
+		}
+		if ( (c == '\n' && m->g->cflags&REG_NEWLINE) ||
+				(c == OUT && !(m->eflags&REG_NOTEOL)) ) {
+			flag = (flag == BOL) ? BOLEOL : EOL;
+			i += m->g->neol;
+		}
+		if (i != 0) {
+			for (; i > 0; i--)
+				st = step(m->g, startst, stopst, st, flag, OUT, st);
+			SP("boleol", st, c);
+		}
+
+		/* how about a word boundary? */
+		if ( (flag == BOL || (lastc != OUT && !ISWORD(lastc))) &&
+					(c != OUT && ISWORD(c)) ) {
+			flag = BOW;
+		}
+		if ( (lastc != OUT && ISWORD(lastc)) &&
+				(flag == EOL || (c != OUT && !ISWORD(c))) ) {
+			flag = EOW;
+		}
+		if (flag == BOW || flag == EOW) {
+			st = step(m->g, startst, stopst, st, flag, OUT, st);
+			SP("boweow", st, c);
+		}
+
+		/* are we done? */
+		if (ISSET(st, stopst) || p == stop)
+			break;		/* NOTE BREAK OUT */
+
+		/* no, we must deal with this character */
+		ASSIGN(tmp, st);
+		ASSIGN(st, fresh);
+		assert(c != OUT);
+		st = step(m->g, startst, stopst, tmp, 0, c, st);
+		SP("aft", st, c);
+		assert(EQ(step(m->g, startst, stopst, st, NOTHING, OUT, st), st));
+		p++;
+	}
+
+	assert(coldp != NULL);
+	m->coldp = coldp;
+	if (ISSET(st, stopst))
+		return(p+1);
+	else
+		return(NULL);
+}
+
+/*
+ - slow - step through the string more deliberately
+ == static const RCHAR_T *slow(register struct match *m, const RCHAR_T *start, \
+ ==	const RCHAR_T *stop, sopno startst, sopno stopst);
+ */
+static const RCHAR_T *			/* where it ended */
+slow(m, start, stop, startst, stopst)
+register struct match *m;
+const RCHAR_T *start;
+const RCHAR_T *stop;
+sopno startst;
+sopno stopst;
+{
+	register states st = m->st;
+	register states empty = m->empty;
+	register states tmp = m->tmp;
+	register const RCHAR_T *p = start;
+	register RCHAR_T c = (start == m->beginp) ? OUT : *(start-1);
+	register RCHAR_T lastc;	/* previous c */
+	register int flag;
+	register int i;
+	register const RCHAR_T *matchp;	/* last p at which a match ended */
+
+	AT("slow", start, stop, startst, stopst);
+	CLEAR(st);
+	SET1(st, startst);
+	SP("sstart", st, *p);
+	st = step(m->g, startst, stopst, st, NOTHING, OUT, st);
+	matchp = NULL;
+	for (;;) {
+		/* next character */
+		lastc = c;
+		c = (p == m->endp) ? OUT : *p;
+
+		/* is there an EOL and/or BOL between lastc and c? */
+		flag = 0;
+		i = 0;
+		if ( (lastc == '\n' && m->g->cflags&REG_NEWLINE) ||
+				(lastc == OUT && !(m->eflags&REG_NOTBOL)) ) {
+			flag = BOL;
+			i = m->g->nbol;
+		}
+		if ( (c == '\n' && m->g->cflags&REG_NEWLINE) ||
+				(c == OUT && !(m->eflags&REG_NOTEOL)) ) {
+			flag = (flag == BOL) ? BOLEOL : EOL;
+			i += m->g->neol;
+		}
+		if (i != 0) {
+			for (; i > 0; i--)
+				st = step(m->g, startst, stopst, st, flag, OUT, st);
+			SP("sboleol", st, c);
+		}
+
+		/* how about a word boundary? */
+		if ( (flag == BOL || (lastc != OUT && !ISWORD(lastc))) &&
+					(c != OUT && ISWORD(c)) ) {
+			flag = BOW;
+		}
+		if ( (lastc != OUT && ISWORD(lastc)) &&
+				(flag == EOL || (c != OUT && !ISWORD(c))) ) {
+			flag = EOW;
+		}
+		if (flag == BOW || flag == EOW) {
+			st = step(m->g, startst, stopst, st, flag, OUT, st);
+			SP("sboweow", st, c);
+		}
+
+		/* are we done? */
+		if (ISSET(st, stopst))
+			matchp = p;
+		if (EQ(st, empty) || p == stop)
+			break;		/* NOTE BREAK OUT */
+
+		/* no, we must deal with this character */
+		ASSIGN(tmp, st);
+		ASSIGN(st, empty);
+		assert(c != OUT);
+		st = step(m->g, startst, stopst, tmp, 0, c, st);
+		SP("saft", st, c);
+		assert(EQ(step(m->g, startst, stopst, st, NOTHING, OUT, st), st));
+		p++;
+	}
+
+	return(matchp);
+}
+
+
+/*
+ - step - map set of states reachable before char to set reachable after
+ == static states step(register struct re_guts *g, sopno start, sopno stop, \
+ ==	register states bef, int flag, RCHAR_T ch, register states aft);
+ == #define	BOL	(1)
+ == #define	EOL	(BOL+1)
+ == #define	BOLEOL	(BOL+2)
+ == #define	NOTHING	(BOL+3)
+ == #define	BOW	(BOL+4)
+ == #define	EOW	(BOL+5)
+ */
+static states
+step(g, start, stop, bef, flag, ch, aft)
+register struct re_guts *g;
+sopno start;			/* start state within strip */
+sopno stop;			/* state after stop state within strip */
+register states bef;		/* states reachable before */
+int flag;			/* NONCHAR flag */
+RCHAR_T ch;			/* character code */
+register states aft;		/* states already known reachable after */
+{
+	register cset *cs;
+	register sop s;
+	register RCHAR_T d;
+	register sopno pc;
+	register onestate here;		/* note, macros know this name */
+	register sopno look;
+	register int i;
+
+	for (pc = start, INIT(here, pc); pc != stop; pc++, INC(here)) {
+		s = g->strip[pc];
+		d = g->stripdata[pc];
+		switch (s) {
+		case OEND:
+			assert(pc == stop-1);
+			break;
+		case OCHAR:
+			/* only characters can match */
+			assert(!flag || ch != d);
+			if (ch == d)
+				FWD(aft, bef, 1);
+			break;
+		case OBOL:
+			if (flag == BOL || flag == BOLEOL)
+				FWD(aft, bef, 1);
+			break;
+		case OEOL:
+			if (flag == EOL || flag == BOLEOL)
+				FWD(aft, bef, 1);
+			break;
+		case OBOW:
+			if (flag == BOW)
+				FWD(aft, bef, 1);
+			break;
+		case OEOW:
+			if (flag == EOW)
+				FWD(aft, bef, 1);
+			break;
+		case OANY:
+			if (!flag)
+				FWD(aft, bef, 1);
+			break;
+		case OANYOF:
+			cs = &g->sets[d];
+			if (!flag && CHIN(cs, ch))
+				FWD(aft, bef, 1);
+			break;
+		case OBACK_:		/* ignored here */
+		case O_BACK:
+			FWD(aft, aft, 1);
+			break;
+		case OPLUS_:		/* forward, this is just an empty */
+			FWD(aft, aft, 1);
+			break;
+		case O_PLUS:		/* both forward and back */
+			FWD(aft, aft, 1);
+			i = ISSETBACK(aft, d);
+			BACK(aft, aft, d);
+			if (!i && ISSETBACK(aft, d)) {
+				/* oho, must reconsider loop body */
+				pc -= d + 1;
+				INIT(here, pc);
+			}
+			break;
+		case OQUEST_:		/* two branches, both forward */
+			FWD(aft, aft, 1);
+			FWD(aft, aft, d);
+			break;
+		case O_QUEST:		/* just an empty */
+			FWD(aft, aft, 1);
+			break;
+		case OLPAREN:		/* not significant here */
+		case ORPAREN:
+			FWD(aft, aft, 1);
+			break;
+		case OCH_:		/* mark the first two branches */
+			FWD(aft, aft, 1);
+			assert(OP(g->strip[pc+d]) == OOR2);
+			FWD(aft, aft, d);
+			break;
+		case OOR1:		/* done a branch, find the O_CH */
+			if (ISSTATEIN(aft, here)) {
+				for (look = 1; /**/; look += d) {
+					s = g->strip[pc+look];
+					d = g->stripdata[pc+look];
+					if (s == O_CH)
+						break;
+					assert(s == OOR2);
+				}
+				FWD(aft, aft, look);
+			}
+			break;
+		case OOR2:		/* propagate OCH_'s marking */
+			FWD(aft, aft, 1);
+			if (g->strip[pc+d] != O_CH) {
+				assert(g->strip[pc+d] == OOR2);
+				FWD(aft, aft, d);
+			}
+			break;
+		case O_CH:		/* just empty */
+			FWD(aft, aft, 1);
+			break;
+		default:		/* ooooops... */
+			assert(nope);
+			break;
+		}
+	}
+
+	return(aft);
+}
+
+#ifdef REDEBUG
+/*
+ - print - print a set of states
+ == #ifdef REDEBUG
+ == static void print(struct match *m, char *caption, states st, \
+ ==	int ch, FILE *d);
+ == #endif
+ */
+static void
+print(m, caption, st, ch, d)
+struct match *m;
+char *caption;
+states st;
+int ch;
+FILE *d;
+{
+	register struct re_guts *g = m->g;
+	register int i;
+	register int first = 1;
+
+	if (!(m->eflags&REG_TRACE))
+		return;
+
+	fprintf(d, "%s", caption);
+	if (ch != '\0')
+		fprintf(d, " %s", pchar(ch));
+	for (i = 0; i < g->nstates; i++)
+		if (ISSET(st, i)) {
+			fprintf(d, "%s%d", (first) ? "\t" : ", ", i);
+			first = 0;
+		}
+	fprintf(d, "\n");
+}
+
+/* 
+ - at - print current situation
+ == #ifdef REDEBUG
+ == static void at(struct match *m, char *title, char *start, char *stop, \
+ ==						sopno startst, sopno stopst);
+ == #endif
+ */
+static void
+at(m, title, start, stop, startst, stopst)
+struct match *m;
+char *title;
+char *start;
+char *stop;
+sopno startst;
+sopno stopst;
+{
+	if (!(m->eflags&REG_TRACE))
+		return;
+
+	printf("%s %s-", title, pchar(*start));
+	printf("%s ", pchar(*stop));
+	printf("%ld-%ld\n", (long)startst, (long)stopst);
+}
+
+#ifndef PCHARDONE
+#define	PCHARDONE	/* never again */
+/*
+ - pchar - make a character printable
+ == #ifdef REDEBUG
+ == static char *pchar(int ch);
+ == #endif
+ *
+ * Is this identical to regchar() over in debug.c?  Well, yes.  But a
+ * duplicate here avoids having a debugging-capable regexec.o tied to
+ * a matching debug.o, and this is convenient.  It all disappears in
+ * the non-debug compilation anyway, so it doesn't matter much.
+ */
+static char *			/* -> representation */
+pchar(ch)
+int ch;
+{
+	static char pbuf[10];
+
+	if (isprint(ch) || ch == ' ')
+		snprintf(pbuf, sizeof(pbuf), "%c", ch);
+	else
+		snprintf(pbuf, sizeof(pbuf), "\\%o", ch);
+	return(pbuf);
+}
+#endif
+#endif
+
+#undef	matcher
+#undef	fast
+#undef	slow
+#undef	dissect
+#undef	backref
+#undef	step
+#undef	print
+#undef	at
+#undef	match
diff --git a/contrib/nvi/regex/re_format.7 b/contrib/nvi/regex/re_format.7
new file mode 100644
index 0000000..61d1aea
--- /dev/null
+++ b/contrib/nvi/regex/re_format.7
@@ -0,0 +1,271 @@
+.\"	$NetBSD: re_format.7,v 1.1.1.2 2008/05/18 14:31:37 aymeric Exp $
+.\"
+.\" Copyright (c) 1992, 1993, 1994 Henry Spencer.
+.\" Copyright (c) 1992, 1993, 1994
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" Henry Spencer of the University of Toronto.
+.\"
+.\" 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.
+.\"
+.\"	@(#)re_format.7	8.2 (Berkeley) 3/16/94
+.\"
+.TH RE_FORMAT 7 "March 16, 1994"
+.SH NAME
+re_format \- POSIX 1003.2 regular expressions
+.SH DESCRIPTION
+Regular expressions (``RE''s),
+as defined in POSIX 1003.2, come in two forms:
+modern REs (roughly those of
+.IR egrep ;
+1003.2 calls these ``extended'' REs)
+and obsolete REs (roughly those of
+.IR ed ;
+1003.2 ``basic'' REs).
+Obsolete REs mostly exist for backward compatibility in some old programs;
+they will be discussed at the end.
+1003.2 leaves some aspects of RE syntax and semantics open;
+`\(dg' marks decisions on these aspects that
+may not be fully portable to other 1003.2 implementations.
+.PP
+A (modern) RE is one\(dg or more non-empty\(dg \fIbranches\fR,
+separated by `|'.
+It matches anything that matches one of the branches.
+.PP
+A branch is one\(dg or more \fIpieces\fR, concatenated.
+It matches a match for the first, followed by a match for the second, etc.
+.PP
+A piece is an \fIatom\fR possibly followed
+by a single\(dg `*', `+', `?', or \fIbound\fR.
+An atom followed by `*' matches a sequence of 0 or more matches of the atom.
+An atom followed by `+' matches a sequence of 1 or more matches of the atom.
+An atom followed by `?' matches a sequence of 0 or 1 matches of the atom.
+.PP
+A \fIbound\fR is `{' followed by an unsigned decimal integer,
+possibly followed by `,'
+possibly followed by another unsigned decimal integer,
+always followed by `}'.
+The integers must lie between 0 and RE_DUP_MAX (255\(dg) inclusive,
+and if there are two of them, the first may not exceed the second.
+An atom followed by a bound containing one integer \fIi\fR
+and no comma matches
+a sequence of exactly \fIi\fR matches of the atom.
+An atom followed by a bound
+containing one integer \fIi\fR and a comma matches
+a sequence of \fIi\fR or more matches of the atom.
+An atom followed by a bound
+containing two integers \fIi\fR and \fIj\fR matches
+a sequence of \fIi\fR through \fIj\fR (inclusive) matches of the atom.
+.PP
+An atom is a regular expression enclosed in `()' (matching a match for the
+regular expression),
+an empty set of `()' (matching the null string)\(dg,
+a \fIbracket expression\fR (see below), `.'
+(matching any single character), `^' (matching the null string at the
+beginning of a line), `$' (matching the null string at the
+end of a line), a `\e' followed by one of the characters
+`^.[$()|*+?{\e'
+(matching that character taken as an ordinary character),
+a `\e' followed by any other character\(dg
+(matching that character taken as an ordinary character,
+as if the `\e' had not been present\(dg),
+or a single character with no other significance (matching that character).
+A `{' followed by a character other than a digit is an ordinary
+character, not the beginning of a bound\(dg.
+It is illegal to end an RE with `\e'.
+.PP
+A \fIbracket expression\fR is a list of characters enclosed in `[]'.
+It normally matches any single character from the list (but see below).
+If the list begins with `^',
+it matches any single character
+(but see below) \fInot\fR from the rest of the list.
+If two characters in the list are separated by `\-', this is shorthand
+for the full \fIrange\fR of characters between those two (inclusive) in the
+collating sequence,
+e.g. `[0-9]' in ASCII matches any decimal digit.
+It is illegal\(dg for two ranges to share an
+endpoint, e.g. `a-c-e'.
+Ranges are very collating-sequence-dependent,
+and portable programs should avoid relying on them.
+.PP
+To include a literal `]' in the list, make it the first character
+(following a possible `^').
+To include a literal `\-', make it the first or last character,
+or the second endpoint of a range.
+To use a literal `\-' as the first endpoint of a range,
+enclose it in `[.' and `.]' to make it a collating element (see below).
+With the exception of these and some combinations using `[' (see next
+paragraphs), all other special characters, including `\e', lose their
+special significance within a bracket expression.
+.PP
+Within a bracket expression, a collating element (a character,
+a multi-character sequence that collates as if it were a single character,
+or a collating-sequence name for either)
+enclosed in `[.' and `.]' stands for the
+sequence of characters of that collating element.
+The sequence is a single element of the bracket expression's list.
+A bracket expression containing a multi-character collating element 
+can thus match more than one character,
+e.g. if the collating sequence includes a `ch' collating element,
+then the RE `[[.ch.]]*c' matches the first five characters
+of `chchcc'.
+.PP
+Within a bracket expression, a collating element enclosed in `[=' and
+`=]' is an equivalence class, standing for the sequences of characters
+of all collating elements equivalent to that one, including itself.
+(If there are no other equivalent collating elements,
+the treatment is as if the enclosing delimiters were `[.' and `.]'.)
+For example, if o and \o'o^' are the members of an equivalence class,
+then `[[=o=]]', `[[=\o'o^'=]]', and `[o\o'o^']' are all synonymous.
+An equivalence class may not\(dg be an endpoint
+of a range.
+.PP
+Within a bracket expression, the name of a \fIcharacter class\fR enclosed
+in `[:' and `:]' stands for the list of all characters belonging to that
+class.
+Standard character class names are:
+.PP
+.RS
+.nf
+.ta 3c 6c 9c
+alnum	digit	punct
+alpha	graph	space
+blank	lower	upper
+cntrl	print	xdigit
+.fi
+.RE
+.PP
+These stand for the character classes defined in
+.IR ctype (3).
+A locale may provide others.
+A character class may not be used as an endpoint of a range.
+.PP
+There are two special cases\(dg of bracket expressions:
+the bracket expressions `[[:<:]]' and `[[:>:]]' match the null string at
+the beginning and end of a word respectively.
+A word is defined as a sequence of
+word characters
+which is neither preceded nor followed by
+word characters.
+A word character is an
+.I alnum
+character (as defined by
+.IR ctype (3))
+or an underscore.
+This is an extension,
+compatible with but not specified by POSIX 1003.2,
+and should be used with
+caution in software intended to be portable to other systems.
+.PP
+In the event that an RE could match more than one substring of a given
+string,
+the RE matches the one starting earliest in the string.
+If the RE could match more than one substring starting at that point,
+it matches the longest.
+Subexpressions also match the longest possible substrings, subject to
+the constraint that the whole match be as long as possible,
+with subexpressions starting earlier in the RE taking priority over
+ones starting later.
+Note that higher-level subexpressions thus take priority over
+their lower-level component subexpressions.
+.PP
+Match lengths are measured in characters, not collating elements.
+A null string is considered longer than no match at all.
+For example,
+`bb*' matches the three middle characters of `abbbc',
+`(wee|week)(knights|nights)' matches all ten characters of `weeknights',
+when `(.*).*' is matched against `abc' the parenthesized subexpression
+matches all three characters, and
+when `(a*)*' is matched against `bc' both the whole RE and the parenthesized
+subexpression match the null string.
+.PP
+If case-independent matching is specified,
+the effect is much as if all case distinctions had vanished from the
+alphabet.
+When an alphabetic that exists in multiple cases appears as an
+ordinary character outside a bracket expression, it is effectively
+transformed into a bracket expression containing both cases,
+e.g. `x' becomes `[xX]'.
+When it appears inside a bracket expression, all case counterparts
+of it are added to the bracket expression, so that (e.g.) `[x]'
+becomes `[xX]' and `[^x]' becomes `[^xX]'.
+.PP
+No particular limit is imposed on the length of REs\(dg.
+Programs intended to be portable should not employ REs longer
+than 256 bytes,
+as an implementation can refuse to accept such REs and remain
+POSIX-compliant.
+.PP
+Obsolete (``basic'') regular expressions differ in several respects.
+`|', `+', and `?' are ordinary characters and there is no equivalent
+for their functionality.
+The delimiters for bounds are `\e{' and `\e}',
+with `{' and `}' by themselves ordinary characters.
+The parentheses for nested subexpressions are `\e(' and `\e)',
+with `(' and `)' by themselves ordinary characters.
+`^' is an ordinary character except at the beginning of the
+RE or\(dg the beginning of a parenthesized subexpression,
+`$' is an ordinary character except at the end of the
+RE or\(dg the end of a parenthesized subexpression,
+and `*' is an ordinary character if it appears at the beginning of the
+RE or the beginning of a parenthesized subexpression
+(after a possible leading `^').
+Finally, there is one new type of atom, a \fIback reference\fR:
+`\e' followed by a non-zero decimal digit \fId\fR
+matches the same sequence of characters
+matched by the \fId\fRth parenthesized subexpression
+(numbering subexpressions by the positions of their opening parentheses,
+left to right),
+so that (e.g.) `\e([bc]\e)\e1' matches `bb' or `cc' but not `bc'.
+.SH SEE ALSO
+regex(3)
+.PP
+POSIX 1003.2, section 2.8 (Regular Expression Notation).
+.SH BUGS
+Having two kinds of REs is a botch.
+.PP
+The current 1003.2 spec says that `)' is an ordinary character in
+the absence of an unmatched `(';
+this was an unintentional result of a wording error,
+and change is likely.
+Avoid relying on it.
+.PP
+Back references are a dreadful botch,
+posing major problems for efficient implementations.
+They are also somewhat vaguely defined
+(does
+`a\e(\e(b\e)*\e2\e)*d' match `abbbd'?).
+Avoid using them.
+.PP
+1003.2's specification of case-independent matching is vague.
+The ``one case implies all cases'' definition given above
+is current consensus among implementors as to the right interpretation.
+.PP
+The syntax for word boundaries is incredibly ugly.
diff --git a/contrib/nvi/regex/regcomp.c b/contrib/nvi/regex/regcomp.c
new file mode 100644
index 0000000..8f7438f
--- /dev/null
+++ b/contrib/nvi/regex/regcomp.c
@@ -0,0 +1,1737 @@
+/*	$NetBSD: regcomp.c,v 1.7 2011/11/19 17:45:11 tnozaki Exp $ */
+
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)regcomp.c	8.4 (Berkeley) 3/19/94
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)regcomp.c	8.4 (Berkeley) 3/19/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <regex.h>
+
+#include "utils.h"
+#include "regex2.h"
+
+#include "cclass.h"
+#include "cname.h"
+
+/*
+ * parse structure, passed up and down to avoid global variables and
+ * other clumsinesses
+ */
+struct parse {
+	RCHAR_T *next;		/* next character in RE */
+	RCHAR_T *end;		/* end of string (-> NUL normally) */
+	int error;		/* has an error been seen? */
+	sop *strip;		/* malloced strip */
+	RCHAR_T *stripdata;	/* malloced stripdata */
+	sopno ssize;		/* malloced strip size (allocated) */
+	sopno slen;		/* malloced strip length (used) */
+	int ncsalloc;		/* number of csets allocated */
+	struct re_guts *g;
+#	define	NPAREN	10	/* we need to remember () 1-9 for back refs */
+	sopno pbegin[NPAREN];	/* -> ( ([0] unused) */
+	sopno pend[NPAREN];	/* -> ) ([0] unused) */
+};
+
+/* ========= begin header generated by ./mkh ========= */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* === regcomp.c === */
+static void p_ere __P((struct parse *p, int stop, size_t reclimit));
+static void p_ere_exp __P((struct parse *p, size_t reclimit));
+static void p_str __P((struct parse *p));
+static void p_bre __P((struct parse *p, int end1, int end2, size_t reclimit));
+static int p_simp_re __P((struct parse *p, int starordinary, size_t reclimit));
+static int p_count __P((struct parse *p));
+static void p_bracket __P((struct parse *p));
+static void p_b_term __P((struct parse *p, cset *cs));
+static void p_b_cclass __P((struct parse *p, cset *cs));
+static void p_b_eclass __P((struct parse *p, cset *cs));
+static char p_b_symbol __P((struct parse *p));
+static char p_b_coll_elem __P((struct parse *p, int endc));
+static char othercase __P((int ch));
+static void bothcases __P((struct parse *p, int ch));
+static void ordinary __P((struct parse *p, int ch));
+static void nonnewline __P((struct parse *p));
+static void repeat __P((struct parse *p, sopno start, int from, int to, size_t reclimit));
+static int seterr __P((struct parse *p, int e));
+static cset *allocset __P((struct parse *p));
+static void freeset __P((struct parse *p, cset *cs));
+static int freezeset __P((struct parse *p, cset *cs));
+static int firstch __P((struct parse *p, cset *cs));
+static int nch __P((struct parse *p, cset *cs));
+static void mcadd __P((struct parse *p, cset *cs, const char *cp));
+#ifdef notdef
+static void mcsub __P((cset *cs, char *cp));
+static int mcin __P((cset *cs, char *cp));
+static char *mcfind __P((cset *cs, char *cp));
+#endif
+static void mcinvert __P((struct parse *p, cset *cs));
+static void mccase __P((struct parse *p, cset *cs));
+#ifdef notdef
+static int isinsets __P((struct re_guts *g, int c));
+static int samesets __P((struct re_guts *g, int c1, int c2));
+#endif
+static void categorize __P((struct parse *p, struct re_guts *g));
+static sopno dupl __P((struct parse *p, sopno start, sopno finish));
+static void doemit __P((struct parse *p, sop op, size_t opnd));
+static void doinsert __P((struct parse *p, sop op, size_t opnd, sopno pos));
+static void dofwd __P((struct parse *p, sopno pos, sop value));
+static int enlarge __P((struct parse *p, sopno size));
+static void stripsnug __P((struct parse *p, struct re_guts *g));
+static void findmust __P((struct parse *p, struct re_guts *g));
+static sopno pluscount __P((struct parse *p, struct re_guts *g));
+
+#ifdef __cplusplus
+}
+#endif
+/* ========= end header generated by ./mkh ========= */
+
+static RCHAR_T nuls[10];		/* place to point scanner in event of error */
+
+/*
+ * macros for use with parse structure
+ * BEWARE:  these know that the parse structure is named `p' !!!
+ */
+#define	PEEK()	(*p->next)
+#define	PEEK2()	(*(p->next+1))
+#define	MORE()	(p->next < p->end)
+#define	MORE2()	(p->next+1 < p->end)
+#define	SEE(c)	(MORE() && PEEK() == (c))
+#define	SEETWO(a, b)	(MORE() && MORE2() && PEEK() == (a) && PEEK2() == (b))
+#define	EAT(c)	((SEE(c)) ? (NEXT(), 1) : 0)
+#define	EATTWO(a, b)	((SEETWO(a, b)) ? (NEXT2(), 1) : 0)
+#define	NEXT()	(p->next++)
+#define	NEXT2()	(p->next += 2)
+#define	NEXTn(n)	(p->next += (n))
+#define	GETNEXT()	(*p->next++)
+#define	SETERROR(e)	seterr(p, (e))
+#define	REQUIRE(co, e)	((co) || SETERROR(e))
+#define	MUSTSEE(c, e)	(REQUIRE(MORE() && PEEK() == (c), e))
+#define	MUSTEAT(c, e)	(REQUIRE(MORE() && GETNEXT() == (c), e))
+#define	MUSTNOTSEE(c, e)	(REQUIRE(!MORE() || PEEK() != (c), e))
+#define	EMIT(op, sopnd)	doemit(p, (sop)(op), (size_t)(sopnd))
+#define	INSERT(op, pos)	doinsert(p, (sop)(op), HERE()-(pos)+1, pos)
+#define	AHEAD(pos)		dofwd(p, pos, HERE()-(pos))
+#define	ASTERN(sop, pos)	EMIT(sop, HERE()-pos)
+#define	HERE()		(p->slen)
+#define	THERE()		(p->slen - 1)
+#define	THERETHERE()	(p->slen - 2)
+#define	DROP(n)	(p->slen -= (n))
+
+#ifndef NDEBUG
+static int never = 0;		/* for use in asserts; shuts lint up */
+#else
+#define	never	0		/* some <assert.h>s have bugs too */
+#endif
+
+#define	MEMLIMIT	0x8000000
+#define MEMSIZE(p) \
+	((p)->ncsalloc / CHAR_BIT * (p)->g->csetsize + \
+	(p)->ncsalloc * sizeof(cset) + \
+	(p)->ssize * sizeof(sop))
+#define	RECLIMIT	256
+
+/*
+ - regcomp - interface for parser and compilation
+ = extern int regcomp(regex_t *, const RCHAR_T *, int);
+ = #define	REG_BASIC	0000
+ = #define	REG_EXTENDED	0001
+ = #define	REG_ICASE	0002
+ = #define	REG_NOSUB	0004
+ = #define	REG_NEWLINE	0010
+ = #define	REG_NOSPEC	0020
+ = #define	REG_PEND	0040
+ = #define	REG_DUMP	0200
+ */
+int				/* 0 success, otherwise REG_something */
+regcomp(regex_t *preg, const RCHAR_T *pattern, int cflags)
+{
+	struct parse pa;
+	register struct re_guts *g;
+	register struct parse *p = &pa;
+	register int i;
+	register size_t len;
+#ifdef REDEBUG
+#	define	GOODFLAGS(f)	(f)
+#else
+#	define	GOODFLAGS(f)	((f)&~REG_DUMP)
+#endif
+
+	cflags = GOODFLAGS(cflags);
+	if ((cflags&REG_EXTENDED) && (cflags&REG_NOSPEC))
+		return(REG_INVARG);
+
+	if (cflags&REG_PEND) {
+		if (preg->re_endp < pattern)
+			return(REG_INVARG);
+		len = preg->re_endp - pattern;
+	} else
+		len = STRLEN(pattern);
+
+	/* do the mallocs early so failure handling is easy */
+	g = (struct re_guts *)malloc(sizeof(struct re_guts) +
+							(NC-1)*sizeof(cat_t));
+	if (g == NULL)
+		return(REG_ESPACE);
+	p->ssize = len/(size_t)2*(size_t)3 + (size_t)1;	/* ugh */
+	p->strip = (sop *)malloc(p->ssize * sizeof(sop));
+	if (p->strip == NULL) {
+		free((char *)g);
+		return(REG_ESPACE);
+	}
+	p->stripdata = (RCHAR_T *)malloc(p->ssize * sizeof(RCHAR_T));
+	if (p->stripdata == NULL) {
+		free((char *)p->strip);
+		free((char *)g);
+		return(REG_ESPACE);
+	}
+	p->slen = 0;
+
+	/* set things up */
+	p->g = g;
+	p->next = (RCHAR_T *)pattern;	/* convenience; we do not modify it */
+	p->end = p->next + len;
+	p->error = 0;
+	p->ncsalloc = 0;
+	for (i = 0; i < NPAREN; i++) {
+		p->pbegin[i] = 0;
+		p->pend[i] = 0;
+	}
+	g->csetsize = NC;
+	g->sets = NULL;
+	g->setbits = NULL;
+	g->ncsets = 0;
+	g->cflags = cflags;
+	g->iflags = 0;
+	g->nbol = 0;
+	g->neol = 0;
+	g->must = NULL;
+	g->mlen = 0;
+	g->nsub = 0;
+#if 0
+	g->ncategories = 1;	/* category 0 is "everything else" */
+	g->categories = &g->catspace[-(CHAR_MIN)];
+	(void) memset((char *)g->catspace, 0, NC*sizeof(cat_t));
+#endif
+	g->backrefs = 0;
+
+	/* do it */
+	EMIT(OEND, 0);
+	g->firststate = THERE();
+	if (cflags&REG_EXTENDED)
+		p_ere(p, OUT, 0);
+	else if (cflags&REG_NOSPEC)
+		p_str(p);
+	else
+		p_bre(p, OUT, OUT, 0);
+	EMIT(OEND, 0);
+	g->laststate = THERE();
+
+	/* tidy up loose ends and fill things in */
+	categorize(p, g);
+	stripsnug(p, g);
+	findmust(p, g);
+	g->nplus = pluscount(p, g);
+	g->magic = MAGIC2;
+	preg->re_nsub = g->nsub;
+	preg->re_g = g;
+	preg->re_magic = MAGIC1;
+#ifndef REDEBUG
+	/* not debugging, so can't rely on the assert() in regexec() */
+	if (g->iflags&BAD)
+		SETERROR(REG_ASSERT);
+#endif
+
+	/* win or lose, we're done */
+	if (p->error != 0)	/* lose */
+		regfree(preg);
+	return(p->error);
+}
+
+/*
+ - p_ere - ERE parser top level, concatenation and alternation
+ == static void p_ere(register struct parse *p, int stop, size_t reclimit);
+ */
+static void
+p_ere(register struct parse *p, int stop, size_t reclimit)
+                         
+         			/* character this ERE should end at */
+{
+	register char c;
+	register sopno prevback = 0;
+	register sopno prevfwd = 0;
+	register sopno conc;
+	register int first = 1;		/* is this the first alternative? */
+
+	if (reclimit++ > RECLIMIT || p->error == REG_ESPACE) {
+		p->error = REG_ESPACE;
+		return;
+	}
+
+	for (;;) {
+		/* do a bunch of concatenated expressions */
+		conc = HERE();
+		while (MORE() && (c = PEEK()) != '|' && c != stop)
+			p_ere_exp(p, reclimit);
+		(void)REQUIRE(HERE() != conc, REG_EMPTY);	/* require nonempty */
+
+		if (!EAT('|'))
+			break;		/* NOTE BREAK OUT */
+
+		if (first) {
+			INSERT(OCH_, conc);	/* offset is wrong */
+			prevfwd = conc;
+			prevback = conc;
+			first = 0;
+		}
+		ASTERN(OOR1, prevback);
+		prevback = THERE();
+		AHEAD(prevfwd);			/* fix previous offset */
+		prevfwd = HERE();
+		EMIT(OOR2, 0);			/* offset is very wrong */
+	}
+
+	if (!first) {		/* tail-end fixups */
+		AHEAD(prevfwd);
+		ASTERN(O_CH, prevback);
+	}
+
+	assert(!MORE() || SEE(stop));
+}
+
+/*
+ - p_ere_exp - parse one subERE, an atom possibly followed by a repetition op
+ == static void p_ere_exp(register struct parse *p);
+ */
+static void
+p_ere_exp(register struct parse *p, size_t reclimit)
+{
+	register char c;
+	register sopno pos;
+	register int count;
+	register int count2;
+	register sopno subno;
+	int wascaret = 0;
+
+	assert(MORE());		/* caller should have ensured this */
+	c = GETNEXT();
+
+	pos = HERE();
+	switch (c) {
+	case '(':
+		(void)REQUIRE(MORE(), REG_EPAREN);
+		p->g->nsub++;
+		subno = p->g->nsub;
+		if (subno < NPAREN)
+			p->pbegin[subno] = HERE();
+		EMIT(OLPAREN, subno);
+		if (!SEE(')'))
+			p_ere(p, ')', reclimit);
+		if (subno < NPAREN) {
+			p->pend[subno] = HERE();
+			assert(p->pend[subno] != 0);
+		}
+		EMIT(ORPAREN, subno);
+		(void)MUSTEAT(')', REG_EPAREN);
+		break;
+#ifndef POSIX_MISTAKE
+	case ')':		/* happens only if no current unmatched ( */
+		/*
+		 * You may ask, why the ifndef?  Because I didn't notice
+		 * this until slightly too late for 1003.2, and none of the
+		 * other 1003.2 regular-expression reviewers noticed it at
+		 * all.  So an unmatched ) is legal POSIX, at least until
+		 * we can get it fixed.
+		 */
+		SETERROR(REG_EPAREN);
+		break;
+#endif
+	case '^':
+		EMIT(OBOL, 0);
+		p->g->iflags |= USEBOL;
+		p->g->nbol++;
+		wascaret = 1;
+		break;
+	case '$':
+		EMIT(OEOL, 0);
+		p->g->iflags |= USEEOL;
+		p->g->neol++;
+		break;
+	case '|':
+		SETERROR(REG_EMPTY);
+		break;
+	case '*':
+	case '+':
+	case '?':
+		SETERROR(REG_BADRPT);
+		break;
+	case '.':
+		if (p->g->cflags&REG_NEWLINE)
+			nonnewline(p);
+		else
+			EMIT(OANY, 0);
+		break;
+	case '[':
+		p_bracket(p);
+		break;
+	case '\\':
+		(void)REQUIRE(MORE(), REG_EESCAPE);
+		c = GETNEXT();
+		ordinary(p, c);
+		break;
+	case '{':		/* okay as ordinary except if digit follows */
+		(void)REQUIRE(!MORE() || !ISDIGIT((UCHAR_T)PEEK()), REG_BADRPT);
+		/* FALLTHROUGH */
+	default:
+		ordinary(p, c);
+		break;
+	}
+
+	if (!MORE())
+		return;
+	c = PEEK();
+	/* we call { a repetition if followed by a digit */
+	if (!( c == '*' || c == '+' || c == '?' ||
+				(c == '{' && MORE2() && ISDIGIT((UCHAR_T)PEEK2())) ))
+		return;		/* no repetition, we're done */
+	NEXT();
+
+	(void)REQUIRE(!wascaret, REG_BADRPT);
+	switch (c) {
+	case '*':	/* implemented as +? */
+		/* this case does not require the (y|) trick, noKLUDGE */
+		INSERT(OPLUS_, pos);
+		ASTERN(O_PLUS, pos);
+		INSERT(OQUEST_, pos);
+		ASTERN(O_QUEST, pos);
+		break;
+	case '+':
+		INSERT(OPLUS_, pos);
+		ASTERN(O_PLUS, pos);
+		break;
+	case '?':
+		/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
+		INSERT(OCH_, pos);		/* offset slightly wrong */
+		ASTERN(OOR1, pos);		/* this one's right */
+		AHEAD(pos);			/* fix the OCH_ */
+		EMIT(OOR2, 0);			/* offset very wrong... */
+		AHEAD(THERE());			/* ...so fix it */
+		ASTERN(O_CH, THERETHERE());
+		break;
+	case '{':
+		count = p_count(p);
+		if (EAT(',')) {
+			if (ISDIGIT((UCHAR_T)PEEK())) {
+				count2 = p_count(p);
+				(void)REQUIRE(count <= count2, REG_BADBR);
+			} else		/* single number with comma */
+				count2 = INFINITY;
+		} else		/* just a single number */
+			count2 = count;
+		repeat(p, pos, count, count2, 0);
+		if (!EAT('}')) {	/* error heuristics */
+			while (MORE() && PEEK() != '}')
+				NEXT();
+			(void)REQUIRE(MORE(), REG_EBRACE);
+			SETERROR(REG_BADBR);
+		}
+		break;
+	}
+
+	if (!MORE())
+		return;
+	c = PEEK();
+	if (!( c == '*' || c == '+' || c == '?' ||
+				(c == '{' && MORE2() && ISDIGIT((UCHAR_T)PEEK2())) ) )
+		return;
+	SETERROR(REG_BADRPT);
+}
+
+/*
+ - p_str - string (no metacharacters) "parser"
+ == static void p_str(register struct parse *p);
+ */
+static void
+p_str(register struct parse *p)
+{
+	(void)REQUIRE(MORE(), REG_EMPTY);
+	while (MORE())
+		ordinary(p, GETNEXT());
+}
+
+/*
+ - p_bre - BRE parser top level, anchoring and concatenation
+ == static void p_bre(register struct parse *p, register int end1, \
+ ==	register int end2, size_t reclimit);
+ * Giving end1 as OUT essentially eliminates the end1/end2 check.
+ *
+ * This implementation is a bit of a kludge, in that a trailing $ is first
+ * taken as an ordinary character and then revised to be an anchor.  The
+ * only undesirable side effect is that '$' gets included as a character
+ * category in such cases.  This is fairly harmless; not worth fixing.
+ * The amount of lookahead needed to avoid this kludge is excessive.
+ */
+static void
+p_bre(register struct parse *p, register int end1, register int end2, size_t reclimit)
+                         
+                  		/* first terminating character */
+                  		/* second terminating character */
+{
+	register sopno start;
+	register int first = 1;			/* first subexpression? */
+	register int wasdollar = 0;
+
+	if (reclimit++ > RECLIMIT || p->error == REG_ESPACE) {
+		p->error = REG_ESPACE;
+		return;
+	}
+
+	start = HERE();
+
+	if (EAT('^')) {
+		EMIT(OBOL, 0);
+		p->g->iflags |= USEBOL;
+		p->g->nbol++;
+	}
+	while (MORE() && !SEETWO(end1, end2)) {
+		wasdollar = p_simp_re(p, first, reclimit);
+		first = 0;
+	}
+	if (wasdollar) {	/* oops, that was a trailing anchor */
+		DROP(1);
+		EMIT(OEOL, 0);
+		p->g->iflags |= USEEOL;
+		p->g->neol++;
+	}
+
+	(void)REQUIRE(HERE() != start, REG_EMPTY);	/* require nonempty */
+}
+
+/*
+ - p_simp_re - parse a simple RE, an atom possibly followed by a repetition
+ == static int p_simp_re(register struct parse *p, int starordinary, size_t reclimit);
+ */
+static int			/* was the simple RE an unbackslashed $? */
+p_simp_re(register struct parse *p, int starordinary, size_t reclimit)
+                         
+                 		/* is a leading * an ordinary character? */
+{
+	register int c;
+	register int count;
+	register int count2;
+	register sopno pos;
+	register int i;
+	register sopno subno;
+	int backsl;
+
+	pos = HERE();		/* repetion op, if any, covers from here */
+
+	assert(MORE());		/* caller should have ensured this */
+	c = GETNEXT();
+	backsl = c == '\\';
+	if (backsl) {
+		(void)REQUIRE(MORE(), REG_EESCAPE);
+		c = (unsigned char)GETNEXT();
+		switch (c) {
+		case '{':
+			SETERROR(REG_BADRPT);
+			break;
+		case '(':
+			p->g->nsub++;
+			subno = p->g->nsub;
+			if (subno < NPAREN)
+				p->pbegin[subno] = HERE();
+			EMIT(OLPAREN, subno);
+			/* the MORE here is an error heuristic */
+			if (MORE() && !SEETWO('\\', ')'))
+				p_bre(p, '\\', ')', reclimit);
+			if (subno < NPAREN) {
+				p->pend[subno] = HERE();
+				assert(p->pend[subno] != 0);
+			}
+			EMIT(ORPAREN, subno);
+			(void)REQUIRE(EATTWO('\\', ')'), REG_EPAREN);
+			break;
+		case ')':	/* should not get here -- must be user */
+		case '}':
+			SETERROR(REG_EPAREN);
+			break;
+		case '1':
+		case '2':
+		case '3':
+		case '4':
+		case '5':
+		case '6':
+		case '7':
+		case '8':
+		case '9':
+			i = c - '0';
+			assert(i < NPAREN);
+			if (p->pend[i] != 0) {
+				assert(i <= p->g->nsub);
+				EMIT(OBACK_, i);
+				assert(p->pbegin[i] != 0);
+				assert(p->strip[p->pbegin[i]] == OLPAREN);
+				assert(p->strip[p->pend[i]] == ORPAREN);
+				(void) dupl(p, p->pbegin[i]+1, p->pend[i]);
+				EMIT(O_BACK, i);
+			} else
+				SETERROR(REG_ESUBREG);
+			p->g->backrefs = 1;
+			break;
+		default:
+			ordinary(p, c);
+			break;
+		}
+	} else {
+		switch (c) {
+		case '.':
+			if (p->g->cflags&REG_NEWLINE)
+				nonnewline(p);
+			else
+				EMIT(OANY, 0);
+			break;
+		case '[':
+			p_bracket(p);
+			break;
+		case '*':
+			(void)REQUIRE(starordinary, REG_BADRPT);
+			/* FALLTHROUGH */
+		default:
+			ordinary(p, c);
+			break;
+		}
+	}
+
+	if (EAT('*')) {		/* implemented as +? */
+		/* this case does not require the (y|) trick, noKLUDGE */
+		INSERT(OPLUS_, pos);
+		ASTERN(O_PLUS, pos);
+		INSERT(OQUEST_, pos);
+		ASTERN(O_QUEST, pos);
+	} else if (EATTWO('\\', '{')) {
+		count = p_count(p);
+		if (EAT(',')) {
+			if (MORE() && ISDIGIT((UCHAR_T)PEEK())) {
+				count2 = p_count(p);
+				(void)REQUIRE(count <= count2, REG_BADBR);
+			} else		/* single number with comma */
+				count2 = INFINITY;
+		} else		/* just a single number */
+			count2 = count;
+		repeat(p, pos, count, count2, reclimit);
+		if (!EATTWO('\\', '}')) {	/* error heuristics */
+			while (MORE() && !SEETWO('\\', '}'))
+				NEXT();
+			(void)REQUIRE(MORE(), REG_EBRACE);
+			SETERROR(REG_BADBR);
+		}
+	} else if (!backsl && c == (unsigned char)'$')	/* $ (but not \$) ends it */
+		return(1);
+
+	return(0);
+}
+
+/*
+ - p_count - parse a repetition count
+ == static int p_count(register struct parse *p);
+ */
+static int			/* the value */
+p_count(register struct parse *p)
+{
+	register int count = 0;
+	register int ndigits = 0;
+
+	while (MORE() && ISDIGIT((UCHAR_T)PEEK()) && count <= DUPMAX) {
+		count = count*10 + (GETNEXT() - '0');
+		ndigits++;
+	}
+
+	(void)REQUIRE(ndigits > 0 && count <= DUPMAX, REG_BADBR);
+	return(count);
+}
+
+/*
+ - p_bracket - parse a bracketed character list
+ == static void p_bracket(register struct parse *p);
+ *
+ * Note a significant property of this code:  if the allocset() did SETERROR,
+ * no set operations are done.
+ */
+static void
+p_bracket(register struct parse *p)
+{
+	register cset *cs;
+	register int invert = 0;
+	static RCHAR_T bow[] = { '[', ':', '<', ':', ']', ']' };
+	static RCHAR_T eow[] = { '[', ':', '>', ':', ']', ']' };
+
+	cs = allocset(p);
+	if (cs == NULL)
+		return;
+
+	/* Dept of Truly Sickening Special-Case Kludges */
+	if (p->next + 5 < p->end && MEMCMP(p->next, bow, 6) == 0) {
+		EMIT(OBOW, 0);
+		NEXTn(6);
+		return;
+	}
+	if (p->next + 5 < p->end && MEMCMP(p->next, eow, 6) == 0) {
+		EMIT(OEOW, 0);
+		NEXTn(6);
+		return;
+	}
+
+	if (EAT('^'))
+		invert++;	/* make note to invert set at end */
+	if (EAT(']'))
+		CHadd(cs, ']');
+	else if (EAT('-'))
+		CHadd(cs, '-');
+	while (MORE() && PEEK() != ']' && !SEETWO('-', ']'))
+		p_b_term(p, cs);
+	if (EAT('-'))
+		CHadd(cs, '-');
+	(void)MUSTEAT(']', REG_EBRACK);
+
+	if (p->error != 0)	/* don't mess things up further */
+		return;
+
+	if (p->g->cflags&REG_ICASE) {
+		register int i;
+		register int ci;
+
+		for (i = p->g->csetsize - 1; i >= 0; i--)
+			if (CHIN(cs, i) && isalpha(i)) {
+				ci = othercase(i);
+				if (ci != i)
+					CHadd(cs, ci);
+			}
+		if (cs->multis != NULL)
+			mccase(p, cs);
+	}
+	if (invert) {
+		register int i;
+
+		for (i = p->g->csetsize - 1; i >= 0; i--)
+			if (CHIN(cs, i))
+				CHsub(cs, i);
+			else
+				CHadd(cs, i);
+		if (p->g->cflags&REG_NEWLINE)
+			CHsub(cs, '\n');
+		if (cs->multis != NULL)
+			mcinvert(p, cs);
+	}
+
+	assert(cs->multis == NULL);		/* xxx */
+
+	if (nch(p, cs) == 1) {		/* optimize singleton sets */
+		ordinary(p, firstch(p, cs));
+		freeset(p, cs);
+	} else
+		EMIT(OANYOF, freezeset(p, cs));
+}
+
+/*
+ - p_b_term - parse one term of a bracketed character list
+ == static void p_b_term(register struct parse *p, register cset *cs);
+ */
+static void
+p_b_term(register struct parse *p, register cset *cs)
+{
+	register char c;
+	register char start, finish;
+	register int i;
+
+	/* classify what we've got */
+	switch ((MORE()) ? PEEK() : '\0') {
+	case '[':
+		c = (MORE2()) ? PEEK2() : '\0';
+		break;
+	case '-':
+		SETERROR(REG_ERANGE);
+		return;			/* NOTE RETURN */
+		break;
+	default:
+		c = '\0';
+		break;
+	}
+
+	switch (c) {
+	case ':':		/* character class */
+		NEXT2();
+		(void)REQUIRE(MORE(), REG_EBRACK);
+		c = PEEK();
+		(void)REQUIRE(c != '-' && c != ']', REG_ECTYPE);
+		p_b_cclass(p, cs);
+		(void)REQUIRE(MORE(), REG_EBRACK);
+		(void)REQUIRE(EATTWO(':', ']'), REG_ECTYPE);
+		break;
+	case '=':		/* equivalence class */
+		NEXT2();
+		(void)REQUIRE(MORE(), REG_EBRACK);
+		c = PEEK();
+		(void)REQUIRE(c != '-' && c != ']', REG_ECOLLATE);
+		p_b_eclass(p, cs);
+		(void)REQUIRE(MORE(), REG_EBRACK);
+		(void)REQUIRE(EATTWO('=', ']'), REG_ECOLLATE);
+		break;
+	default:		/* symbol, ordinary character, or range */
+/* xxx revision needed for multichar stuff */
+		start = p_b_symbol(p);
+		if (SEE('-') && MORE2() && PEEK2() != ']') {
+			/* range */
+			NEXT();
+			if (EAT('-'))
+				finish = '-';
+			else
+				finish = p_b_symbol(p);
+		} else
+			finish = start;
+/* xxx what about signed chars here... */
+		(void)REQUIRE(start <= finish, REG_ERANGE);
+		for (i = start; i <= finish; i++)
+			CHadd(cs, i);
+		break;
+	}
+}
+
+/*
+ - p_b_cclass - parse a character-class name and deal with it
+ == static void p_b_cclass(register struct parse *p, register cset *cs);
+ */
+static void
+p_b_cclass(register struct parse *p, register cset *cs)
+{
+	register RCHAR_T *sp = p->next;
+	register struct cclass *cp;
+	register size_t len;
+	register const char *u;
+	register char c;
+
+	while (MORE() && isalpha(PEEK()))
+		NEXT();
+	len = p->next - sp;
+	for (cp = cclasses; cp->name != NULL; cp++)
+		if (STRLEN(cp->name) == len && !MEMCMP(cp->name, sp, len))
+			break;
+	if (cp->name == NULL) {
+		/* oops, didn't find it */
+		SETERROR(REG_ECTYPE);
+		return;
+	}
+
+	u = cp->chars;
+	while ((c = *u++) != '\0')
+		CHadd(cs, c);
+	for (u = cp->multis; *u != '\0'; u += strlen(u) + 1)
+		MCadd(p, cs, u);
+}
+
+/*
+ - p_b_eclass - parse an equivalence-class name and deal with it
+ == static void p_b_eclass(register struct parse *p, register cset *cs);
+ *
+ * This implementation is incomplete. xxx
+ */
+static void
+p_b_eclass(register struct parse *p, register cset *cs)
+{
+	register char c;
+
+	c = p_b_coll_elem(p, '=');
+	CHadd(cs, c);
+}
+
+/*
+ - p_b_symbol - parse a character or [..]ed multicharacter collating symbol
+ == static char p_b_symbol(register struct parse *p);
+ */
+static char			/* value of symbol */
+p_b_symbol(register struct parse *p)
+{
+	register char value;
+
+	(void)REQUIRE(MORE(), REG_EBRACK);
+	if (!EATTWO('[', '.'))
+		return(GETNEXT());
+
+	/* collating symbol */
+	value = p_b_coll_elem(p, '.');
+	(void)REQUIRE(EATTWO('.', ']'), REG_ECOLLATE);
+	return(value);
+}
+
+/*
+ - p_b_coll_elem - parse a collating-element name and look it up
+ == static char p_b_coll_elem(register struct parse *p, int endc);
+ */
+static char			/* value of collating element */
+p_b_coll_elem(register struct parse *p, int endc)
+                         
+         			/* name ended by endc,']' */
+{
+	register RCHAR_T *sp = p->next;
+	register struct cname *cp;
+	register size_t len;
+
+	while (MORE() && !SEETWO(endc, ']'))
+		NEXT();
+	if (!MORE()) {
+		SETERROR(REG_EBRACK);
+		return(0);
+	}
+	len = p->next - sp;
+	for (cp = cnames; cp->name != NULL; cp++)
+		if (STRLEN(cp->name) == len && MEMCMP(cp->name, sp, len))
+			return(cp->code);	/* known name */
+	if (len == 1)
+		return(*sp);	/* single character */
+	SETERROR(REG_ECOLLATE);			/* neither */
+	return(0);
+}
+
+/*
+ - othercase - return the case counterpart of an alphabetic
+ == static char othercase(int ch);
+ */
+static char			/* if no counterpart, return ch */
+othercase(int ch)
+{
+	assert(isalpha(ch));
+	if (isupper(ch))
+		return(tolower(ch));
+	else if (islower(ch))
+		return(toupper(ch));
+	else			/* peculiar, but could happen */
+		return(ch);
+}
+
+/*
+ - bothcases - emit a dualcase version of a two-case character
+ == static void bothcases(register struct parse *p, int ch);
+ *
+ * Boy, is this implementation ever a kludge...
+ */
+static void
+bothcases(register struct parse *p, int ch)
+{
+	register RCHAR_T *oldnext = p->next;
+	register RCHAR_T *oldend = p->end;
+	RCHAR_T bracket[3];
+
+	assert(othercase(ch) != ch);	/* p_bracket() would recurse */
+	p->next = bracket;
+	p->end = bracket+2;
+	bracket[0] = ch;
+	bracket[1] = ']';
+	bracket[2] = '\0';
+	p_bracket(p);
+	assert(p->next == bracket+2);
+	p->next = oldnext;
+	p->end = oldend;
+}
+
+/*
+ - ordinary - emit an ordinary character
+ == static void ordinary(register struct parse *p, register int ch);
+ */
+static void
+ordinary(register struct parse *p, register int ch)
+{
+/*
+	register cat_t *cap = p->g->categories;
+*/
+
+	if ((p->g->cflags&REG_ICASE) && isalpha(ch) && othercase(ch) != ch)
+		bothcases(p, ch);
+	else {
+		EMIT(OCHAR, (UCHAR_T)ch);
+/*
+		if (cap[ch] == 0)
+			cap[ch] = p->g->ncategories++;
+*/
+	}
+}
+
+/*
+ - nonnewline - emit REG_NEWLINE version of OANY
+ == static void nonnewline(register struct parse *p);
+ *
+ * Boy, is this implementation ever a kludge...
+ */
+static void
+nonnewline(register struct parse *p)
+{
+	register RCHAR_T *oldnext = p->next;
+	register RCHAR_T *oldend = p->end;
+	RCHAR_T bracket[4];
+
+	p->next = bracket;
+	p->end = bracket+3;
+	bracket[0] = '^';
+	bracket[1] = '\n';
+	bracket[2] = ']';
+	bracket[3] = '\0';
+	p_bracket(p);
+	assert(p->next == bracket+3);
+	p->next = oldnext;
+	p->end = oldend;
+}
+
+/*
+ - repeat - generate code for a bounded repetition, recursively if needed
+ == static void repeat(register struct parse *p, sopno start, int from, int to, size_t reclimit);
+ */
+static void
+repeat(register struct parse *p, sopno start, int from, int to, size_t reclimit)
+                         
+            			/* operand from here to end of strip */
+         			/* repeated from this number */
+       				/* to this number of times (maybe INFINITY) */
+{
+	register sopno finish;
+#	define	N	2
+#	define	INF	3
+#	define	REP(f, t)	((f)*8 + (t))
+#	define	MAP(n)	(((n) <= 1) ? (n) : ((n) == INFINITY) ? INF : N)
+	register sopno copy;
+
+	if (reclimit++ > RECLIMIT) 
+		p->error = REG_ESPACE;
+	if (p->error)
+		return;
+
+	finish = HERE();
+
+	assert(from <= to);
+
+	switch (REP(MAP(from), MAP(to))) {
+	case REP(0, 0):			/* must be user doing this */
+		DROP(finish-start);	/* drop the operand */
+		break;
+	case REP(0, 1):			/* as x{1,1}? */
+	case REP(0, N):			/* as x{1,n}? */
+	case REP(0, INF):		/* as x{1,}? */
+		/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
+		INSERT(OCH_, start);		/* offset is wrong... */
+		repeat(p, start+1, 1, to, reclimit);
+		ASTERN(OOR1, start);
+		AHEAD(start);			/* ... fix it */
+		EMIT(OOR2, 0);
+		AHEAD(THERE());
+		ASTERN(O_CH, THERETHERE());
+		break;
+	case REP(1, 1):			/* trivial case */
+		/* done */
+		break;
+	case REP(1, N):			/* as x?x{1,n-1} */
+		/* KLUDGE: emit y? as (y|) until subtle bug gets fixed */
+		INSERT(OCH_, start);
+		ASTERN(OOR1, start);
+		AHEAD(start);
+		EMIT(OOR2, 0);			/* offset very wrong... */
+		AHEAD(THERE());			/* ...so fix it */
+		ASTERN(O_CH, THERETHERE());
+		copy = dupl(p, start+1, finish+1);
+		assert(copy == finish+4);
+		repeat(p, copy, 1, to-1, reclimit);
+		break;
+	case REP(1, INF):		/* as x+ */
+		INSERT(OPLUS_, start);
+		ASTERN(O_PLUS, start);
+		break;
+	case REP(N, N):			/* as xx{m-1,n-1} */
+		copy = dupl(p, start, finish);
+		repeat(p, copy, from-1, to-1, reclimit);
+		break;
+	case REP(N, INF):		/* as xx{n-1,INF} */
+		copy = dupl(p, start, finish);
+		repeat(p, copy, from-1, to, reclimit);
+		break;
+	default:			/* "can't happen" */
+		SETERROR(REG_ASSERT);	/* just in case */
+		break;
+	}
+}
+
+/*
+ - seterr - set an error condition
+ == static int seterr(register struct parse *p, int e);
+ */
+static int			/* useless but makes type checking happy */
+seterr(register struct parse *p, int e)
+{
+	if (p->error == 0)	/* keep earliest error condition */
+		p->error = e;
+	p->next = nuls;		/* try to bring things to a halt */
+	p->end = nuls;
+	return(0);		/* make the return value well-defined */
+}
+
+/*
+ - allocset - allocate a set of characters for []
+ == static cset *allocset(register struct parse *p);
+ */
+static cset *
+allocset(register struct parse *p)
+{
+	register int no = p->g->ncsets++;
+	register size_t nc;
+	register size_t nbytes;
+	register cset *cs;
+	register size_t css = (size_t)p->g->csetsize;
+	register int i;
+
+	if (no >= p->ncsalloc) {	/* need another column of space */
+		p->ncsalloc += CHAR_BIT;
+		nc = p->ncsalloc;
+		assert(nc % CHAR_BIT == 0);
+		nbytes = nc / CHAR_BIT * css;
+		if (MEMSIZE(p) > MEMLIMIT)
+			goto oomem;
+		if (p->g->sets == NULL)
+			p->g->sets = (cset *)malloc(nc * sizeof(cset));
+		else
+			p->g->sets = (cset *)realloc((char *)p->g->sets,
+							nc * sizeof(cset));
+		if (p->g->setbits == NULL)
+			p->g->setbits = (uch *)malloc(nbytes);
+		else {
+			p->g->setbits = (uch *)realloc((char *)p->g->setbits,
+								nbytes);
+			/* xxx this isn't right if setbits is now NULL */
+			for (i = 0; i < no; i++)
+				p->g->sets[i].ptr = p->g->setbits + css*(i/CHAR_BIT);
+		}
+		if (p->g->sets != NULL && p->g->setbits != NULL)
+			(void) memset((char *)p->g->setbits + (nbytes - css),
+								0, css);
+		else {
+oomem:
+			no = 0;
+			SETERROR(REG_ESPACE);
+			/* caller's responsibility not to do set ops */
+			return NULL;
+		}
+	}
+
+	cs = &p->g->sets[no];
+	cs->ptr = p->g->setbits + css*((no)/CHAR_BIT);
+	cs->mask = 1 << ((no) % CHAR_BIT);
+	cs->hash = 0;
+	cs->smultis = 0;
+	cs->multis = NULL;
+
+	return(cs);
+}
+
+/*
+ - freeset - free a now-unused set
+ == static void freeset(register struct parse *p, register cset *cs);
+ */
+static void
+freeset(register struct parse *p, register cset *cs)
+{
+	register size_t i;
+	register cset *top = &p->g->sets[p->g->ncsets];
+	register size_t css = (size_t)p->g->csetsize;
+
+	for (i = 0; i < css; i++)
+		CHsub(cs, i);
+	if (cs == top-1)	/* recover only the easy case */
+		p->g->ncsets--;
+}
+
+/*
+ - freezeset - final processing on a set of characters
+ == static int freezeset(register struct parse *p, register cset *cs);
+ *
+ * The main task here is merging identical sets.  This is usually a waste
+ * of time (although the hash code minimizes the overhead), but can win
+ * big if REG_ICASE is being used.  REG_ICASE, by the way, is why the hash
+ * is done using addition rather than xor -- all ASCII [aA] sets xor to
+ * the same value!
+ */
+static int			/* set number */
+freezeset(register struct parse *p, register cset *cs)
+{
+	register uch h = cs->hash;
+	register size_t i;
+	register cset *top = &p->g->sets[p->g->ncsets];
+	register cset *cs2;
+	register size_t css = (size_t)p->g->csetsize;
+
+	/* look for an earlier one which is the same */
+	for (cs2 = &p->g->sets[0]; cs2 < top; cs2++)
+		if (cs2->hash == h && cs2 != cs) {
+			/* maybe */
+			for (i = 0; i < css; i++)
+				if (!!CHIN(cs2, i) != !!CHIN(cs, i))
+					break;		/* no */
+			if (i == css)
+				break;			/* yes */
+		}
+
+	if (cs2 < top) {	/* found one */
+		freeset(p, cs);
+		cs = cs2;
+	}
+
+	return((int)(cs - p->g->sets));
+}
+
+/*
+ - firstch - return first character in a set (which must have at least one)
+ == static int firstch(register struct parse *p, register cset *cs);
+ */
+static int			/* character; there is no "none" value */
+firstch(register struct parse *p, register cset *cs)
+{
+	register size_t i;
+	register size_t css = (size_t)p->g->csetsize;
+
+	for (i = 0; i < css; i++)
+		if (CHIN(cs, i))
+			return((char)i);
+	assert(never);
+	return(0);		/* arbitrary */
+}
+
+/*
+ - nch - number of characters in a set
+ == static int nch(register struct parse *p, register cset *cs);
+ */
+static int
+nch(register struct parse *p, register cset *cs)
+{
+	register size_t i;
+	register size_t css = (size_t)p->g->csetsize;
+	register int n = 0;
+
+	for (i = 0; i < css; i++)
+		if (CHIN(cs, i))
+			n++;
+	return(n);
+}
+
+/*
+ - mcadd - add a collating element to a cset
+ == static void mcadd(register struct parse *p, register cset *cs, \
+ ==	register char *cp);
+ */
+static void
+mcadd(register struct parse *p, register cset *cs, register const char *cp)
+{
+	register size_t oldend = cs->smultis;
+	void *np;
+
+	cs->smultis += strlen(cp) + 1;
+	np = realloc(cs->multis, cs->smultis);
+	if (np == NULL) {
+		if (cs->multis)
+			free(cs->multis);
+		cs->multis = NULL;
+		SETERROR(REG_ESPACE);
+		return;
+	}
+	cs->multis = np;
+
+	(void) strlcpy(cs->multis + oldend - 1, cp, cs->smultis - oldend + 1);
+}
+
+#ifdef notdef
+/*
+ - mcsub - subtract a collating element from a cset
+ == static void mcsub(register cset *cs, register char *cp);
+ */
+static void
+mcsub(register cset *cs, register char *cp)
+{
+	register char *fp = mcfind(cs, cp);
+	register size_t len = strlen(fp);
+
+	assert(fp != NULL);
+	(void) memmove(fp, fp + len + 1,
+				cs->smultis - (fp + len + 1 - cs->multis));
+	cs->smultis -= len;
+
+	if (cs->smultis == 0) {
+		free(cs->multis);
+		cs->multis = NULL;
+		return;
+	}
+
+	cs->multis = realloc(cs->multis, cs->smultis);
+	assert(cs->multis != NULL);
+}
+
+/*
+ - mcin - is a collating element in a cset?
+ == static int mcin(register cset *cs, register char *cp);
+ */
+static int
+mcin(register cset *cs, register char *cp)
+{
+	return(mcfind(cs, cp) != NULL);
+}
+
+/*
+ - mcfind - find a collating element in a cset
+ == static char *mcfind(register cset *cs, register char *cp);
+ */
+static char *
+mcfind(register cset *cs, register char *cp)
+{
+	register char *p;
+
+	if (cs->multis == NULL)
+		return(NULL);
+	for (p = cs->multis; *p != '\0'; p += strlen(p) + 1)
+		if (strcmp(cp, p) == 0)
+			return(p);
+	return(NULL);
+}
+#endif
+
+/*
+ - mcinvert - invert the list of collating elements in a cset
+ == static void mcinvert(register struct parse *p, register cset *cs);
+ *
+ * This would have to know the set of possibilities.  Implementation
+ * is deferred.
+ */
+static void
+mcinvert(register struct parse *p, register cset *cs)
+{
+	assert(cs->multis == NULL);	/* xxx */
+}
+
+/*
+ - mccase - add case counterparts of the list of collating elements in a cset
+ == static void mccase(register struct parse *p, register cset *cs);
+ *
+ * This would have to know the set of possibilities.  Implementation
+ * is deferred.
+ */
+static void
+mccase(register struct parse *p, register cset *cs)
+{
+	assert(cs->multis == NULL);	/* xxx */
+}
+
+#ifdef notdef
+/*
+ - isinsets - is this character in any sets?
+ == static int isinsets(register struct re_guts *g, int c);
+ */
+static int			/* predicate */
+isinsets(register struct re_guts *g, int c)
+{
+	register uch *col;
+	register int i;
+	register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
+	register unsigned uc = (unsigned char)c;
+
+	for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
+		if (col[uc] != 0)
+			return(1);
+	return(0);
+}
+
+/*
+ - samesets - are these two characters in exactly the same sets?
+ == static int samesets(register struct re_guts *g, int c1, int c2);
+ */
+static int			/* predicate */
+samesets(register struct re_guts *g, int c1, int c2)
+{
+	register uch *col;
+	register int i;
+	register int ncols = (g->ncsets+(CHAR_BIT-1)) / CHAR_BIT;
+	register unsigned uc1 = (unsigned char)c1;
+	register unsigned uc2 = (unsigned char)c2;
+
+	for (i = 0, col = g->setbits; i < ncols; i++, col += g->csetsize)
+		if (col[uc1] != col[uc2])
+			return(0);
+	return(1);
+}
+#endif
+
+/*
+ - categorize - sort out character categories
+ == static void categorize(struct parse *p, register struct re_guts *g);
+ */
+static void
+categorize(struct parse *p, register struct re_guts *g)
+{
+#ifdef notdef
+	register cat_t *cats = g->categories;
+	register int c;
+	register int c2;
+	register cat_t cat;
+
+	/* avoid making error situations worse */
+	if (p->error != 0)
+		return;
+
+	for (c = CHAR_MIN; c <= CHAR_MAX; c++)
+		if (cats[c] == 0 && isinsets(g, c)) {
+			cat = g->ncategories++;
+			cats[c] = cat;
+			for (c2 = c+1; c2 <= CHAR_MAX; c2++)
+				if (cats[c2] == 0 && samesets(g, c, c2))
+					cats[c2] = cat;
+		}
+#endif
+}
+
+/*
+ - dupl - emit a duplicate of a bunch of sops
+ == static sopno dupl(register struct parse *p, sopno start, sopno finish);
+ */
+static sopno			/* start of duplicate */
+dupl(register struct parse *p, sopno start, sopno finish)
+                         
+            			/* from here */
+             			/* to this less one */
+{
+	register sopno ret = HERE();
+	register sopno len = finish - start;
+
+	assert(finish >= start);
+	if (len == 0)
+		return(ret);
+	if (!enlarge(p, p->ssize + len))	/* this many unexpected additions */
+		return ret;
+	assert(p->ssize >= p->slen + len);
+	(void) memcpy((char *)(p->strip + p->slen),
+		(char *)(p->strip + start), (size_t)len*sizeof(sop));
+	(void) memcpy((char *)(p->stripdata + p->slen),
+		(char *)(p->stripdata + start), (size_t)len*sizeof(RCHAR_T));
+	p->slen += len;
+	return(ret);
+}
+
+/*
+ - doemit - emit a strip operator
+ == static void doemit(register struct parse *p, sop op, size_t opnd);
+ *
+ * It might seem better to implement this as a macro with a function as
+ * hard-case backup, but it's just too big and messy unless there are
+ * some changes to the data structures.  Maybe later.
+ */
+static void
+doemit(register struct parse *p, sop op, size_t opnd)
+{
+	/* avoid making error situations worse */
+	if (p->error != 0)
+		return;
+
+	/* deal with oversize operands ("can't happen", more or less) */
+	assert(opnd < 1);
+
+	/* deal with undersized strip */
+	if (p->slen >= p->ssize)
+		if (!enlarge(p, (p->ssize+1) / 2 * 3))	/* +50% */
+			return;
+
+	/* finally, it's all reduced to the easy case */
+	p->strip[p->slen] = op;
+	p->stripdata[p->slen] = opnd;
+	p->slen++;
+}
+
+/*
+ - doinsert - insert a sop into the strip
+ == static void doinsert(register struct parse *p, sop op, size_t opnd, sopno pos);
+ */
+static void
+doinsert(register struct parse *p, sop op, size_t opnd, sopno pos)
+{
+	register sopno sn;
+	register sop s;
+	register RCHAR_T d;
+	register int i;
+
+	/* avoid making error situations worse */
+	if (p->error != 0)
+		return;
+
+	sn = HERE();
+	EMIT(op, opnd);		/* do checks, ensure space */
+	assert(HERE() == sn+1);
+	s = p->strip[sn];
+	d = p->stripdata[sn];
+
+	/* adjust paren pointers */
+	assert(pos > 0);
+	for (i = 1; i < NPAREN; i++) {
+		if (p->pbegin[i] >= pos) {
+			p->pbegin[i]++;
+		}
+		if (p->pend[i] >= pos) {
+			p->pend[i]++;
+		}
+	}
+
+	memmove((char *)&p->strip[pos+1], (char *)&p->strip[pos],
+						(HERE()-pos-1)*sizeof(sop));
+	memmove((char *)&p->stripdata[pos+1], (char *)&p->stripdata[pos],
+						(HERE()-pos-1)*sizeof(RCHAR_T));
+	p->strip[pos] = s;
+	p->stripdata[pos] = d;
+}
+
+/*
+ - dofwd - complete a forward reference
+ == static void dofwd(register struct parse *p, sopno pos, sop value);
+ */
+static void
+dofwd(register struct parse *p, register sopno pos, sop value)
+{
+	/* avoid making error situations worse */
+	if (p->error != 0)
+		return;
+
+	assert(value < 1);
+	p->stripdata[pos] = value;
+}
+
+/*
+ - enlarge - enlarge the strip
+ == static int enlarge(register struct parse *p, sopno size);
+ */
+static int
+enlarge(register struct parse *p, register sopno size)
+{
+	register sop *sp;
+	register RCHAR_T *dp;
+	sopno osize;
+
+	if (p->ssize >= size)
+		return 1;
+
+	osize = p->ssize;
+	p->ssize = size;
+	if (MEMSIZE(p) > MEMLIMIT)
+		goto oomem;
+	sp = realloc(p->strip, p->ssize * sizeof(sop));
+	if (sp == NULL)
+		goto oomem;
+	p->strip = sp;
+	dp = realloc(p->stripdata, p->ssize * sizeof(RCHAR_T));
+	if (dp == NULL) {
+oomem:
+		p->ssize = osize;
+		SETERROR(REG_ESPACE);
+		return 0;
+	}
+	p->stripdata = dp;
+	return 1;
+}
+
+/*
+ - stripsnug - compact the strip
+ == static void stripsnug(register struct parse *p, register struct re_guts *g);
+ */
+static void
+stripsnug(register struct parse *p, register struct re_guts *g)
+{
+	g->nstates = p->slen;
+	g->strip = (sop *)realloc((char *)p->strip,
+	    p->slen * sizeof(sop));
+	if (g->strip == NULL) {
+		SETERROR(REG_ESPACE);
+		g->strip = p->strip;
+	}
+	g->stripdata = (RCHAR_T *)realloc((char *)p->stripdata,
+	    p->slen * sizeof(RCHAR_T));
+	if (g->stripdata == NULL) {
+		SETERROR(REG_ESPACE);
+		g->stripdata = p->stripdata;
+	}
+}
+
+/*
+ - findmust - fill in must and mlen with longest mandatory literal string
+ == static void findmust(register struct parse *p, register struct re_guts *g);
+ *
+ * This algorithm could do fancy things like analyzing the operands of |
+ * for common subsequences.  Someday.  This code is simple and finds most
+ * of the interesting cases.
+ *
+ * Note that must and mlen got initialized during setup.
+ */
+static void
+findmust(struct parse *p, register struct re_guts *g)
+{
+	register sop *scans;
+	register RCHAR_T *scand;
+	sop *starts = 0;
+	RCHAR_T *startd = NULL;
+	register sop *newstarts = 0;
+	register RCHAR_T *newstartd = NULL;
+	register sopno newlen;
+	register sop s;
+	register RCHAR_T d;
+	register RCHAR_T *cp;
+	register sopno i;
+
+	/* avoid making error situations worse */
+	if (p->error != 0)
+		return;
+
+	/* find the longest OCHAR sequence in strip */
+	newlen = 0;
+	scans = g->strip + 1;
+	scand = g->stripdata + 1;
+	do {
+		s = *scans++;
+		d = *scand++;
+		switch (s) {
+		case OCHAR:		/* sequence member */
+			if (newlen == 0) {		/* new sequence */
+				newstarts = scans - 1;
+				newstartd = scand - 1;
+			}
+			newlen++;
+			break;
+		case OPLUS_:		/* things that don't break one */
+		case OLPAREN:
+		case ORPAREN:
+			break;
+		case OQUEST_:		/* things that must be skipped */
+		case OCH_:
+			scans--;
+			scand--;
+			do {
+				scans += d;
+				scand += d;
+				s = *scans;
+				d = *scand;
+				/* assert() interferes w debug printouts */
+				if (s != O_QUEST && s != O_CH && s != OOR2) {
+					g->iflags |= BAD;
+					return;
+				}
+			} while (s != O_QUEST && s != O_CH);
+			/* fallthrough */
+		default:		/* things that break a sequence */
+			if (newlen > g->mlen) {		/* ends one */
+				starts = newstarts;
+				startd = newstartd;
+				g->mlen = newlen;
+			}
+			newlen = 0;
+			break;
+		}
+	} while (s != OEND);
+
+	if (g->mlen == 0)		/* there isn't one */
+		return;
+
+	/* turn it into a character string */
+	g->must = malloc(((size_t)g->mlen + 1) * sizeof(RCHAR_T));
+	if (g->must == NULL) {		/* argh; just forget it */
+		g->mlen = 0;
+		return;
+	}
+	cp = g->must;
+	scans = starts;
+	scand = startd;
+	for (i = g->mlen; i > 0; i--) {
+		for (;;) {
+			s = *scans++;
+			d = *scand++;
+			if (s == OCHAR)
+				break;
+		}
+		assert(cp < g->must + g->mlen);
+		*cp++ = d;
+	}
+	assert(cp == g->must + g->mlen);
+	*cp++ = '\0';		/* just on general principles */
+}
+
+/*
+ - pluscount - count + nesting
+ == static sopno pluscount(register struct parse *p, register struct re_guts *g);
+ */
+static sopno			/* nesting depth */
+pluscount(struct parse *p, register struct re_guts *g)
+{
+	register sop *scan;
+	register sop s;
+	register sopno plusnest = 0;
+	register sopno maxnest = 0;
+
+	if (p->error != 0)
+		return(0);	/* there may not be an OEND */
+
+	scan = g->strip + 1;
+	do {
+		s = *scan++;
+		switch (s) {
+		case OPLUS_:
+			plusnest++;
+			break;
+		case O_PLUS:
+			if (plusnest > maxnest)
+				maxnest = plusnest;
+			plusnest--;
+			break;
+		}
+	} while (s != OEND);
+	if (plusnest != 0)
+		g->iflags |= BAD;
+	return(maxnest);
+}
diff --git a/contrib/nvi/regex/regerror.c b/contrib/nvi/regex/regerror.c
new file mode 100644
index 0000000..5ff1f6b
--- /dev/null
+++ b/contrib/nvi/regex/regerror.c
@@ -0,0 +1,176 @@
+/*	$NetBSD: regerror.c,v 1.2 2008/12/05 22:51:43 christos Exp $ */
+
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)regerror.c	8.3 (Berkeley) 3/19/94
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)regerror.c	8.3 (Berkeley) 3/19/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <regex.h>
+
+#include "utils.h"
+
+/* ========= begin header generated by ./mkh ========= */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* === regerror.c === */
+static char *regatoi __P((const regex_t *preg, char *localbuf));
+
+#ifdef __cplusplus
+}
+#endif
+/* ========= end header generated by ./mkh ========= */
+/*
+ = #define	REG_NOMATCH	 1
+ = #define	REG_BADPAT	 2
+ = #define	REG_ECOLLATE	 3
+ = #define	REG_ECTYPE	 4
+ = #define	REG_EESCAPE	 5
+ = #define	REG_ESUBREG	 6
+ = #define	REG_EBRACK	 7
+ = #define	REG_EPAREN	 8
+ = #define	REG_EBRACE	 9
+ = #define	REG_BADBR	10
+ = #define	REG_ERANGE	11
+ = #define	REG_ESPACE	12
+ = #define	REG_BADRPT	13
+ = #define	REG_EMPTY	14
+ = #define	REG_ASSERT	15
+ = #define	REG_INVARG	16
+ = #define	REG_ATOI	255	// convert name to number (!)
+ = #define	REG_ITOA	0400	// convert number to name (!)
+ */
+static struct rerr {
+	int code;
+	const char *name;
+	const char *explain;
+} rerrs[] = {
+	{ REG_NOMATCH,	"REG_NOMATCH",	"regexec() failed to match" },
+	{ REG_BADPAT,	"REG_BADPAT",	"invalid regular expression" },
+	{ REG_ECOLLATE,	"REG_ECOLLATE",	"invalid collating element" },
+	{ REG_ECTYPE,	"REG_ECTYPE",	"invalid character class" },
+	{ REG_EESCAPE,	"REG_EESCAPE",	"trailing backslash (\\)" },
+	{ REG_ESUBREG,	"REG_ESUBREG",	"invalid backreference number" },
+	{ REG_EBRACK,	"REG_EBRACK",	"brackets ([ ]) not balanced" },
+	{ REG_EPAREN,	"REG_EPAREN",	"parentheses not balanced" },
+	{ REG_EBRACE,	"REG_EBRACE",	"braces not balanced" },
+	{ REG_BADBR,	"REG_BADBR",	"invalid repetition count(s)" },
+	{ REG_ERANGE,	"REG_ERANGE",	"invalid character range" },
+	{ REG_ESPACE,	"REG_ESPACE",	"out of memory" },
+	{ REG_BADRPT,	"REG_BADRPT",	"repetition-operator operand invalid" },
+	{ REG_EMPTY,	"REG_EMPTY",	"empty (sub)expression" },
+	{ REG_ASSERT,	"REG_ASSERT",	"\"can't happen\" -- you found a bug" },
+	{ REG_INVARG,	"REG_INVARG",	"invalid argument to regex routine" },
+	{ 0,		"",		"*** unknown regexp error code ***" },
+};
+
+/*
+ - regerror - the interface to error numbers
+ = extern size_t regerror(int, const regex_t *, char *, size_t);
+ */
+/* ARGSUSED */
+size_t
+regerror(int errcode, const regex_t *preg, char *errbuf, size_t errbuf_size)
+{
+	register struct rerr *r;
+	register size_t len;
+	register int target = errcode &~ REG_ITOA;
+	register const char *s;
+	char convbuf[50];
+
+	if (errcode == REG_ATOI)
+		s = regatoi(preg, convbuf);
+	else {
+		for (r = rerrs; r->code != 0; r++)
+			if (r->code == target)
+				break;
+	
+		if (errcode&REG_ITOA) {
+			if (r->code != 0) {
+				assert(strlen(r->name) < sizeof(convbuf));
+				(void) strlcpy(convbuf, r->name, sizeof(convbuf));
+			} else
+				(void) snprintf(convbuf, sizeof(convbuf),
+				    "REG_0x%x", target);
+			s = convbuf;
+		} else
+			s = r->explain;
+	}
+
+	len = strlen(s) + 1;
+	if (errbuf_size > 0) {
+		(void) strlcpy(errbuf, s, errbuf_size);
+	}
+
+	return(len);
+}
+
+/*
+ - regatoi - internal routine to implement REG_ATOI
+ == static char *regatoi(const regex_t *preg, char *localbuf);
+ */
+static char *
+regatoi(const regex_t *preg, char *localbuf)
+{
+#if 0 /* we don't seem to use this and it gives a warning. */
+	register struct rerr *r;
+	register size_t siz;
+	register char *p;
+
+	for (r = rerrs; r->code != 0; r++)
+		if (strcmp(r->name, preg->re_endp) == 0)
+			break;
+	if (r->code == 0)
+		return("0");
+
+	sprintf(localbuf, "%d", r->code);
+#else
+	*localbuf = '\0';
+#endif
+	return(localbuf);
+}
diff --git a/contrib/nvi/regex/regex.3 b/contrib/nvi/regex/regex.3
new file mode 100644
index 0000000..2c17254
--- /dev/null
+++ b/contrib/nvi/regex/regex.3
@@ -0,0 +1,540 @@
+.\"	$NetBSD: regex.3,v 1.1.1.2 2008/05/18 14:31:38 aymeric Exp $
+.\"
+.\" Copyright (c) 1992, 1993, 1994 Henry Spencer.
+.\" Copyright (c) 1992, 1993, 1994
+.\"	The Regents of the University of California.  All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" Henry Spencer of the University of Toronto.
+.\"
+.\" 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.
+.\"
+.\"	@(#)regex.3	8.2 (Berkeley) 3/16/94
+.\"
+.TH REGEX 3 "March 16, 1994"
+.de ZR
+.\" one other place knows this name:  the SEE ALSO section
+.IR re_format (7) \\$1
+..
+.SH NAME
+regcomp, regexec, regerror, regfree \- regular-expression library
+.SH SYNOPSIS
+.ft B
+.\".na
+#include <sys/types.h>
+.br
+#include <regex.h>
+.HP 10
+int regcomp(regex_t\ *preg, const\ char\ *pattern, int\ cflags);
+.HP
+int\ regexec(const\ regex_t\ *preg, const\ char\ *string,
+size_t\ nmatch, regmatch_t\ pmatch[], int\ eflags);
+.HP
+size_t\ regerror(int\ errcode, const\ regex_t\ *preg,
+char\ *errbuf, size_t\ errbuf_size);
+.HP
+void\ regfree(regex_t\ *preg);
+.\".ad
+.ft
+.SH DESCRIPTION
+These routines implement POSIX 1003.2 regular expressions (``RE''s);
+see
+.ZR .
+.I Regcomp
+compiles an RE written as a string into an internal form,
+.I regexec
+matches that internal form against a string and reports results,
+.I regerror
+transforms error codes from either into human-readable messages,
+and
+.I regfree
+frees any dynamically-allocated storage used by the internal form
+of an RE.
+.PP
+The header
+.I <regex.h>
+declares two structure types,
+.I regex_t
+and
+.IR regmatch_t ,
+the former for compiled internal forms and the latter for match reporting.
+It also declares the four functions,
+a type
+.IR regoff_t ,
+and a number of constants with names starting with ``REG_''.
+.PP
+.I Regcomp
+compiles the regular expression contained in the
+.I pattern
+string,
+subject to the flags in
+.IR cflags ,
+and places the results in the
+.I regex_t
+structure pointed to by
+.IR preg .
+.I Cflags
+is the bitwise OR of zero or more of the following flags:
+.IP REG_EXTENDED \w'REG_EXTENDED'u+2n
+Compile modern (``extended'') REs,
+rather than the obsolete (``basic'') REs that
+are the default.
+.IP REG_BASIC
+This is a synonym for 0,
+provided as a counterpart to REG_EXTENDED to improve readability.
+.IP REG_NOSPEC
+Compile with recognition of all special characters turned off.
+All characters are thus considered ordinary,
+so the ``RE'' is a literal string.
+This is an extension,
+compatible with but not specified by POSIX 1003.2,
+and should be used with
+caution in software intended to be portable to other systems.
+REG_EXTENDED and REG_NOSPEC may not be used
+in the same call to
+.IR regcomp .
+.IP REG_ICASE
+Compile for matching that ignores upper/lower case distinctions.
+See
+.ZR .
+.IP REG_NOSUB
+Compile for matching that need only report success or failure,
+not what was matched.
+.IP REG_NEWLINE
+Compile for newline-sensitive matching.
+By default, newline is a completely ordinary character with no special
+meaning in either REs or strings.
+With this flag,
+`[^' bracket expressions and `.' never match newline,
+a `^' anchor matches the null string after any newline in the string
+in addition to its normal function,
+and the `$' anchor matches the null string before any newline in the
+string in addition to its normal function.
+.IP REG_PEND
+The regular expression ends,
+not at the first NUL,
+but just before the character pointed to by the
+.I re_endp
+member of the structure pointed to by
+.IR preg .
+The
+.I re_endp
+member is of type
+.IR const\ char\ * .
+This flag permits inclusion of NULs in the RE;
+they are considered ordinary characters.
+This is an extension,
+compatible with but not specified by POSIX 1003.2,
+and should be used with
+caution in software intended to be portable to other systems.
+.PP
+When successful,
+.I regcomp
+returns 0 and fills in the structure pointed to by
+.IR preg .
+One member of that structure
+(other than
+.IR re_endp )
+is publicized:
+.IR re_nsub ,
+of type
+.IR size_t ,
+contains the number of parenthesized subexpressions within the RE
+(except that the value of this member is undefined if the
+REG_NOSUB flag was used).
+If
+.I regcomp
+fails, it returns a non-zero error code;
+see DIAGNOSTICS.
+.PP
+.I Regexec
+matches the compiled RE pointed to by
+.I preg
+against the
+.IR string ,
+subject to the flags in
+.IR eflags ,
+and reports results using
+.IR nmatch ,
+.IR pmatch ,
+and the returned value.
+The RE must have been compiled by a previous invocation of
+.IR regcomp .
+The compiled form is not altered during execution of
+.IR regexec ,
+so a single compiled RE can be used simultaneously by multiple threads.
+.PP
+By default,
+the NUL-terminated string pointed to by
+.I string
+is considered to be the text of an entire line, minus any terminating
+newline.
+The
+.I eflags
+argument is the bitwise OR of zero or more of the following flags:
+.IP REG_NOTBOL \w'REG_STARTEND'u+2n
+The first character of
+the string
+is not the beginning of a line, so the `^' anchor should not match before it.
+This does not affect the behavior of newlines under REG_NEWLINE.
+.IP REG_NOTEOL
+The NUL terminating
+the string
+does not end a line, so the `$' anchor should not match before it.
+This does not affect the behavior of newlines under REG_NEWLINE.
+.IP REG_STARTEND
+The string is considered to start at
+\fIstring\fR\ + \fIpmatch\fR[0].\fIrm_so\fR
+and to have a terminating NUL located at
+\fIstring\fR\ + \fIpmatch\fR[0].\fIrm_eo\fR
+(there need not actually be a NUL at that location),
+regardless of the value of
+.IR nmatch .
+See below for the definition of
+.IR pmatch
+and
+.IR nmatch .
+This is an extension,
+compatible with but not specified by POSIX 1003.2,
+and should be used with
+caution in software intended to be portable to other systems.
+Note that a non-zero \fIrm_so\fR does not imply REG_NOTBOL;
+REG_STARTEND affects only the location of the string,
+not how it is matched.
+.PP
+See
+.ZR
+for a discussion of what is matched in situations where an RE or a
+portion thereof could match any of several substrings of
+.IR string .
+.PP
+Normally,
+.I regexec
+returns 0 for success and the non-zero code REG_NOMATCH for failure.
+Other non-zero error codes may be returned in exceptional situations;
+see DIAGNOSTICS.
+.PP
+If REG_NOSUB was specified in the compilation of the RE,
+or if
+.I nmatch
+is 0,
+.I regexec
+ignores the
+.I pmatch
+argument (but see below for the case where REG_STARTEND is specified).
+Otherwise,
+.I pmatch
+points to an array of
+.I nmatch
+structures of type
+.IR regmatch_t .
+Such a structure has at least the members
+.I rm_so
+and
+.IR rm_eo ,
+both of type
+.I regoff_t
+(a signed arithmetic type at least as large as an
+.I off_t
+and a
+.IR ssize_t ),
+containing respectively the offset of the first character of a substring
+and the offset of the first character after the end of the substring.
+Offsets are measured from the beginning of the
+.I string
+argument given to
+.IR regexec .
+An empty substring is denoted by equal offsets,
+both indicating the character following the empty substring.
+.PP
+The 0th member of the
+.I pmatch
+array is filled in to indicate what substring of
+.I string
+was matched by the entire RE.
+Remaining members report what substring was matched by parenthesized
+subexpressions within the RE;
+member
+.I i
+reports subexpression
+.IR i ,
+with subexpressions counted (starting at 1) by the order of their opening
+parentheses in the RE, left to right.
+Unused entries in the array\(emcorresponding either to subexpressions that
+did not participate in the match at all, or to subexpressions that do not
+exist in the RE (that is, \fIi\fR\ > \fIpreg\fR\->\fIre_nsub\fR)\(emhave both
+.I rm_so
+and
+.I rm_eo
+set to \-1.
+If a subexpression participated in the match several times,
+the reported substring is the last one it matched.
+(Note, as an example in particular, that when the RE `(b*)+' matches `bbb',
+the parenthesized subexpression matches each of the three `b's and then
+an infinite number of empty strings following the last `b',
+so the reported substring is one of the empties.)
+.PP
+If REG_STARTEND is specified,
+.I pmatch
+must point to at least one
+.I regmatch_t
+(even if
+.I nmatch
+is 0 or REG_NOSUB was specified),
+to hold the input offsets for REG_STARTEND.
+Use for output is still entirely controlled by
+.IR nmatch ;
+if
+.I nmatch
+is 0 or REG_NOSUB was specified,
+the value of
+.IR pmatch [0]
+will not be changed by a successful
+.IR regexec .
+.PP
+.I Regerror
+maps a non-zero
+.I errcode
+from either
+.I regcomp
+or
+.I regexec
+to a human-readable, printable message.
+If
+.I preg
+is non-NULL,
+the error code should have arisen from use of
+the
+.I regex_t
+pointed to by
+.IR preg ,
+and if the error code came from
+.IR regcomp ,
+it should have been the result from the most recent
+.I regcomp
+using that
+.IR regex_t .
+.RI ( Regerror
+may be able to supply a more detailed message using information
+from the
+.IR regex_t .)
+.I Regerror
+places the NUL-terminated message into the buffer pointed to by
+.IR errbuf ,
+limiting the length (including the NUL) to at most
+.I errbuf_size
+bytes.
+If the whole message won't fit,
+as much of it as will fit before the terminating NUL is supplied.
+In any case,
+the returned value is the size of buffer needed to hold the whole
+message (including terminating NUL).
+If
+.I errbuf_size
+is 0,
+.I errbuf
+is ignored but the return value is still correct.
+.PP
+If the
+.I errcode
+given to
+.I regerror
+is first ORed with REG_ITOA,
+the ``message'' that results is the printable name of the error code,
+e.g. ``REG_NOMATCH'',
+rather than an explanation thereof.
+If
+.I errcode
+is REG_ATOI,
+then
+.I preg
+shall be non-NULL and the
+.I re_endp
+member of the structure it points to
+must point to the printable name of an error code;
+in this case, the result in
+.I errbuf
+is the decimal digits of
+the numeric value of the error code
+(0 if the name is not recognized).
+REG_ITOA and REG_ATOI are intended primarily as debugging facilities;
+they are extensions,
+compatible with but not specified by POSIX 1003.2,
+and should be used with
+caution in software intended to be portable to other systems.
+Be warned also that they are considered experimental and changes are possible.
+.PP
+.I Regfree
+frees any dynamically-allocated storage associated with the compiled RE
+pointed to by
+.IR preg .
+The remaining
+.I regex_t
+is no longer a valid compiled RE
+and the effect of supplying it to
+.I regexec
+or
+.I regerror
+is undefined.
+.PP
+None of these functions references global variables except for tables
+of constants;
+all are safe for use from multiple threads if the arguments are safe.
+.SH IMPLEMENTATION CHOICES
+There are a number of decisions that 1003.2 leaves up to the implementor,
+either by explicitly saying ``undefined'' or by virtue of them being
+forbidden by the RE grammar.
+This implementation treats them as follows.
+.PP
+See
+.ZR
+for a discussion of the definition of case-independent matching.
+.PP
+There is no particular limit on the length of REs,
+except insofar as memory is limited.
+Memory usage is approximately linear in RE size, and largely insensitive
+to RE complexity, except for bounded repetitions.
+See BUGS for one short RE using them
+that will run almost any system out of memory.
+.PP
+A backslashed character other than one specifically given a magic meaning
+by 1003.2 (such magic meanings occur only in obsolete [``basic''] REs)
+is taken as an ordinary character.
+.PP
+Any unmatched [ is a REG_EBRACK error.
+.PP
+Equivalence classes cannot begin or end bracket-expression ranges.
+The endpoint of one range cannot begin another.
+.PP
+RE_DUP_MAX, the limit on repetition counts in bounded repetitions, is 255.
+.PP
+A repetition operator (?, *, +, or bounds) cannot follow another
+repetition operator.
+A repetition operator cannot begin an expression or subexpression
+or follow `^' or `|'.
+.PP
+`|' cannot appear first or last in a (sub)expression or after another `|',
+i.e. an operand of `|' cannot be an empty subexpression.
+An empty parenthesized subexpression, `()', is legal and matches an
+empty (sub)string.
+An empty string is not a legal RE.
+.PP
+A `{' followed by a digit is considered the beginning of bounds for a
+bounded repetition, which must then follow the syntax for bounds.
+A `{' \fInot\fR followed by a digit is considered an ordinary character.
+.PP
+`^' and `$' beginning and ending subexpressions in obsolete (``basic'')
+REs are anchors, not ordinary characters.
+.SH SEE ALSO
+grep(1), re_format(7)
+.PP
+POSIX 1003.2, sections 2.8 (Regular Expression Notation)
+and
+B.5 (C Binding for Regular Expression Matching).
+.SH DIAGNOSTICS
+Non-zero error codes from
+.I regcomp
+and
+.I regexec
+include the following:
+.PP
+.nf
+.ta \w'REG_ECOLLATE'u+3n
+REG_NOMATCH	regexec() failed to match
+REG_BADPAT	invalid regular expression
+REG_ECOLLATE	invalid collating element
+REG_ECTYPE	invalid character class
+REG_EESCAPE	\e applied to unescapable character
+REG_ESUBREG	invalid backreference number
+REG_EBRACK	brackets [ ] not balanced
+REG_EPAREN	parentheses ( ) not balanced
+REG_EBRACE	braces { } not balanced
+REG_BADBR	invalid repetition count(s) in { }
+REG_ERANGE	invalid character range in [ ]
+REG_ESPACE	ran out of memory
+REG_BADRPT	?, *, or + operand invalid
+REG_EMPTY	empty (sub)expression
+REG_ASSERT	``can't happen''\(emyou found a bug
+REG_INVARG	invalid argument, e.g. negative-length string
+.fi
+.SH HISTORY
+Originally written by Henry Spencer at University of Toronto.
+Altered for inclusion in the 4.4BSD distribution.
+.SH BUGS
+This is an alpha release with known defects.
+Please report problems.
+.PP
+There is one known functionality bug.
+The implementation of internationalization is incomplete:
+the locale is always assumed to be the default one of 1003.2,
+and only the collating elements etc. of that locale are available.
+.PP
+The back-reference code is subtle and doubts linger about its correctness
+in complex cases.
+.PP
+.I Regexec
+performance is poor.
+This will improve with later releases.
+.I Nmatch
+exceeding 0 is expensive;
+.I nmatch
+exceeding 1 is worse.
+.I Regexec
+is largely insensitive to RE complexity \fIexcept\fR that back
+references are massively expensive.
+RE length does matter; in particular, there is a strong speed bonus
+for keeping RE length under about 30 characters,
+with most special characters counting roughly double.
+.PP
+.I Regcomp
+implements bounded repetitions by macro expansion,
+which is costly in time and space if counts are large
+or bounded repetitions are nested.
+An RE like, say,
+`((((a{1,100}){1,100}){1,100}){1,100}){1,100}'
+will (eventually) run almost any existing machine out of swap space.
+.PP
+There are suspected problems with response to obscure error conditions.
+Notably,
+certain kinds of internal overflow,
+produced only by truly enormous REs or by multiply nested bounded repetitions,
+are probably not handled well.
+.PP
+Due to a mistake in 1003.2, things like `a)b' are legal REs because `)' is
+a special character only in the presence of a previous unmatched `('.
+This can't be fixed until the spec is fixed.
+.PP
+The standard's definition of back references is vague.
+For example, does
+`a\e(\e(b\e)*\e2\e)*d' match `abbbd'?
+Until the standard is clarified,
+behavior in such cases should not be relied on.
+.PP
+The implementation of word-boundary matching is a bit of a kludge,
+and bugs may lurk in combinations of word-boundary matching and anchoring.
diff --git a/contrib/nvi/regex/regex.h b/contrib/nvi/regex/regex.h
new file mode 100644
index 0000000..cabd66b
--- /dev/null
+++ b/contrib/nvi/regex/regex.h
@@ -0,0 +1,109 @@
+/*	$NetBSD: regex.h,v 1.1.1.2 2008/05/18 14:31:38 aymeric Exp $ */
+
+/*-
+ * Copyright (c) 1992 Henry Spencer.
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)regex.h	8.1 (Berkeley) 6/2/93
+ */
+
+#ifndef _REGEX_H_
+#define	_REGEX_H_
+
+#ifdef __REGEX_PRIVATE
+#include "config.h"
+#include "../common/multibyte.h"
+#endif
+
+/* types */
+typedef off_t regoff_t;
+
+typedef struct {
+	int re_magic;
+	size_t re_nsub;		/* number of parenthesized subexpressions */
+	const RCHAR_T *re_endp;	/* end pointer for REG_PEND */
+	struct re_guts *re_g;	/* none of your business :-) */
+} regex_t;
+
+typedef struct {
+	regoff_t rm_so;		/* start of match */
+	regoff_t rm_eo;		/* end of match */
+} regmatch_t;
+
+/* regcomp() flags */
+#define	REG_BASIC	0000
+#define	REG_EXTENDED	0001
+#define	REG_ICASE	0002
+#define	REG_NOSUB	0004
+#define	REG_NEWLINE	0010
+#define	REG_NOSPEC	0020
+#define	REG_PEND	0040
+#define	REG_DUMP	0200
+
+/* regerror() flags */
+#define	REG_NOMATCH	 1
+#define	REG_BADPAT	 2
+#define	REG_ECOLLATE	 3
+#define	REG_ECTYPE	 4
+#define	REG_EESCAPE	 5
+#define	REG_ESUBREG	 6
+#define	REG_EBRACK	 7
+#define	REG_EPAREN	 8
+#define	REG_EBRACE	 9
+#define	REG_BADBR	10
+#define	REG_ERANGE	11
+#define	REG_ESPACE	12
+#define	REG_BADRPT	13
+#define	REG_EMPTY	14
+#define	REG_ASSERT	15
+#define	REG_INVARG	16
+#define	REG_ATOI	255	/* convert name to number (!) */
+#define	REG_ITOA	0400	/* convert number to name (!) */
+
+/* regexec() flags */
+#define	REG_NOTBOL	00001
+#define	REG_NOTEOL	00002
+#define	REG_STARTEND	00004
+#define	REG_TRACE	00400	/* tracing of execution */
+#define	REG_LARGE	01000	/* force large representation */
+#define	REG_BACKR	02000	/* force use of backref code */
+
+int	regcomp __P((regex_t *, const RCHAR_T *, int));
+size_t	regerror __P((int, const regex_t *, char *, size_t));
+int	regexec __P((const regex_t *,
+	    const RCHAR_T *, size_t, regmatch_t [], int));
+void	regfree __P((regex_t *));
+
+#endif /* !_REGEX_H_ */
diff --git a/contrib/nvi/regex/regex2.h b/contrib/nvi/regex/regex2.h
new file mode 100644
index 0000000..7c93528
--- /dev/null
+++ b/contrib/nvi/regex/regex2.h
@@ -0,0 +1,174 @@
+/*	$NetBSD: regex2.h,v 1.5 2011/11/23 15:43:39 tnozaki Exp $ */
+
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)regex2.h	8.3 (Berkeley) 3/16/94
+ */
+
+/*
+ * First, the stuff that ends up in the outside-world include file
+ = typedef off_t regoff_t;
+ = typedef struct {
+ = 	int re_magic;
+ = 	size_t re_nsub;		// number of parenthesized subexpressions
+ = 	const char *re_endp;	// end pointer for REG_PEND
+ = 	struct re_guts *re_g;	// none of your business :-)
+ = } regex_t;
+ = typedef struct {
+ = 	regoff_t rm_so;		// start of match
+ = 	regoff_t rm_eo;		// end of match
+ = } regmatch_t;
+ */
+/*
+ * internals of regex_t
+ */
+#define	MAGIC1	((('r'^0200)<<8) | 'e')
+
+/*
+ * The internal representation is a *strip*, a sequence of
+ * operators ending with an endmarker.  (Some terminology etc. is a
+ * historical relic of earlier versions which used multiple strips.)
+ * Certain oddities in the representation are there to permit running
+ * the machinery backwards; in particular, any deviation from sequential
+ * flow must be marked at both its source and its destination.  Some
+ * fine points:
+ *
+ * - OPLUS_ and O_PLUS are *inside* the loop they create.
+ * - OQUEST_ and O_QUEST are *outside* the bypass they create.
+ * - OCH_ and O_CH are *outside* the multi-way branch they create, while
+ *   OOR1 and OOR2 are respectively the end and the beginning of one of
+ *   the branches.  Note that there is an implicit OOR2 following OCH_
+ *   and an implicit OOR1 preceding O_CH.
+ *
+ * In state representations, an operator's bit is on to signify a state
+ * immediately *preceding* "execution" of that operator.
+ */
+typedef char sop;	/* strip operator */
+typedef size_t sopno;
+/* operators			   meaning	operand			*/
+/*						(back, fwd are offsets)	*/
+#define	OEND	(1)		/* endmarker	-			*/
+#define	OCHAR	(2)		/* character	unsigned char		*/
+#define	OBOL	(3)		/* left anchor	-			*/
+#define	OEOL	(4)		/* right anchor	-			*/
+#define	OANY	(5)		/* .		-			*/
+#define	OANYOF	(6)		/* [...]	set number		*/
+#define	OBACK_	(7)		/* begin \d	paren number		*/
+#define	O_BACK	(8)		/* end \d	paren number		*/
+#define	OPLUS_	(9)		/* + prefix	fwd to suffix		*/
+#define	O_PLUS	(10)		/* + suffix	back to prefix		*/
+#define	OQUEST_	(11)		/* ? prefix	fwd to suffix		*/
+#define	O_QUEST	(12)		/* ? suffix	back to prefix		*/
+#define	OLPAREN	(13)		/* (		fwd to )		*/
+#define	ORPAREN	(14)		/* )		back to (		*/
+#define	OCH_	(15)		/* begin choice	fwd to OOR2		*/
+#define	OOR1	(16)		/* | pt. 1	back to OOR1 or OCH_	*/
+#define	OOR2	(17)		/* | pt. 2	fwd to OOR2 or O_CH	*/
+#define	O_CH	(18)		/* end choice	back to OOR1		*/
+#define	OBOW	(19)		/* begin word	-			*/
+#define	OEOW	(20)		/* end word	-			*/
+
+/*
+ * Structure for [] character-set representation.  Character sets are
+ * done as bit vectors, grouped 8 to a byte vector for compactness.
+ * The individual set therefore has both a pointer to the byte vector
+ * and a mask to pick out the relevant bit of each byte.  A hash code
+ * simplifies testing whether two sets could be identical.
+ *
+ * This will get trickier for multicharacter collating elements.  As
+ * preliminary hooks for dealing with such things, we also carry along
+ * a string of multi-character elements, and decide the size of the
+ * vectors at run time.
+ */
+typedef struct {
+	uch *ptr;		/* -> uch [csetsize] */
+	uch mask;		/* bit within array */
+	uch hash;		/* hash code */
+	size_t smultis;
+	char *multis;		/* -> char[smulti]  ab\0cd\0ef\0\0 */
+} cset;
+/* note that CHadd and CHsub are unsafe, and CHIN doesn't yield 0/1 */
+#define	CHadd(cs, c)	((cs)->ptr[(uch)(c)] |= (cs)->mask, (cs)->hash += (c))
+#define	CHsub(cs, c)	((cs)->ptr[(uch)(c)] &= ~(cs)->mask, (cs)->hash -= (c))
+#define	CHIN(cs, c)	((cs)->ptr[(uch)(c)] & (cs)->mask)
+#define	MCadd(p, cs, cp)	mcadd(p, cs, cp)	/* regcomp() internal fns */
+#define	MCsub(p, cs, cp)	mcsub(p, cs, cp)
+#define	MCin(p, cs, cp)	mcin(p, cs, cp)
+
+/* stuff for character categories */
+typedef RCHAR_T cat_t;
+
+/*
+ * main compiled-expression structure
+ */
+struct re_guts {
+	int magic;
+#		define	MAGIC2	((('R'^0200)<<8)|'E')
+	sop *strip;		/* malloced area for strip */
+	RCHAR_T *stripdata;	/* malloced area for stripdata */
+	size_t csetsize;	/* number of bits in a cset vector */
+	size_t ncsets;		/* number of csets in use */
+	cset *sets;		/* -> cset [ncsets] */
+	uch *setbits;		/* -> uch[csetsize][ncsets/CHAR_BIT] */
+	int cflags;		/* copy of regcomp() cflags argument */
+	sopno nstates;		/* = number of sops */
+	sopno firststate;	/* the initial OEND (normally 0) */
+	sopno laststate;	/* the final OEND */
+	int iflags;		/* internal flags */
+#		define	USEBOL	01	/* used ^ */
+#		define	USEEOL	02	/* used $ */
+#		define	BAD	04	/* something wrong */
+	size_t nbol;		/* number of ^ used */
+	size_t neol;		/* number of $ used */
+#if 0
+	size_t ncategories;	/* how many character categories */
+	cat_t *categories;	/* ->catspace[-CHAR_MIN] */
+#endif
+	RCHAR_T *must;		/* match must contain this string */
+	size_t mlen;		/* length of must */
+	size_t nsub;		/* copy of re_nsub */
+	int backrefs;		/* does it use back references? */
+	sopno nplus;		/* how deep does it nest +s? */
+	/* catspace must be last */
+#if 0
+	cat_t catspace[1];	/* actually [NC] */
+#endif
+};
+
+/* misc utilities */
+#define OUT	REOF	/* a non-character value */
+#define	ISWORD(c) ((c) == '_' || (ISGRAPH((UCHAR_T)c) && !ISPUNCT((UCHAR_T)c)))
diff --git a/contrib/nvi/regex/regexec.c b/contrib/nvi/regex/regexec.c
new file mode 100644
index 0000000..89ab2ca
--- /dev/null
+++ b/contrib/nvi/regex/regexec.c
@@ -0,0 +1,180 @@
+/*	$NetBSD: regexec.c,v 1.4 2009/10/31 20:11:53 dsl Exp $ */
+
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)regexec.c	8.2 (Berkeley) 3/16/94
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)regexec.c	8.2 (Berkeley) 3/16/94";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * the outer shell of regexec()
+ *
+ * This file includes engine.c *twice*, after muchos fiddling with the
+ * macros that code uses.  This lets the same code operate on two different
+ * representations for state sets.
+ */
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <ctype.h>
+#include <regex.h>
+
+#include "utils.h"
+#include "regex2.h"
+
+#ifdef notdef
+static int nope = 0;		/* for use in asserts; shuts lint up */
+#endif
+
+/* macros for manipulating states, small version */
+#define	states	int
+#define	states1	int		/* for later use in regexec() decision */
+#define	CLEAR(v)	((v) = 0)
+#define	SET0(v, n)	((v) &= ~(1 << (n)))
+#define	SET1(v, n)	((v) |= 1 << (n))
+#define	ISSET(v, n)	((v) & (1 << (n)))
+#define	ASSIGN(d, s)	((d) = (s))
+#define	EQ(a, b)	((a) == (b))
+#define	STATEVARS	int dummy	/* dummy version */
+#define	STATESETUP(m, n)	/* nothing */
+#define	STATETEARDOWN(m)	/* nothing */
+#define	SETUP(v)	((v) = 0)
+#define	onestate	int
+#define	INIT(o, n)	((o) = (unsigned)1 << (n))
+#define	INC(o)	((o) <<= 1)
+#define	ISSTATEIN(v, o)	((v) & (o))
+/* some abbreviations; note that some of these know variable names! */
+/* do "if I'm here, I can also be there" etc without branches */
+#define	FWD(dst, src, n)	((dst) |= ((unsigned)(src)&(here)) << (n))
+#define	BACK(dst, src, n)	((dst) |= ((unsigned)(src)&(here)) >> (n))
+#define	ISSETBACK(v, n)	((v) & ((unsigned)here >> (n)))
+/* function names */
+#define SNAMES			/* engine.c looks after details */
+
+#include "engine.c"
+
+/* now undo things */
+#undef	states
+#undef	CLEAR
+#undef	SET0
+#undef	SET1
+#undef	ISSET
+#undef	ASSIGN
+#undef	EQ
+#undef	STATEVARS
+#undef	STATESETUP
+#undef	STATETEARDOWN
+#undef	SETUP
+#undef	onestate
+#undef	INIT
+#undef	INC
+#undef	ISSTATEIN
+#undef	FWD
+#undef	BACK
+#undef	ISSETBACK
+#undef	SNAMES
+
+/* macros for manipulating states, large version */
+#define	states	char *
+#define	CLEAR(v)	memset(v, 0, m->g->nstates)
+#define	SET0(v, n)	((v)[n] = 0)
+#define	SET1(v, n)	((v)[n] = 1)
+#define	ISSET(v, n)	((v)[n])
+#define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
+#define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
+#define	STATEVARS	int vn; char *space
+#define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
+				if ((m)->space == NULL) return(REG_ESPACE); \
+				(m)->vn = 0; }
+#define	STATETEARDOWN(m)	{ free((m)->space); }
+#define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
+#define	onestate	int
+#define	INIT(o, n)	((o) = (n))
+#define	INC(o)	((o)++)
+#define	ISSTATEIN(v, o)	((v)[o])
+/* some abbreviations; note that some of these know variable names! */
+/* do "if I'm here, I can also be there" etc without branches */
+#define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
+#define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
+#define	ISSETBACK(v, n)	((v)[here - (n)])
+/* function names */
+#define	LNAMES			/* flag */
+
+#include "engine.c"
+
+/*
+ - regexec - interface for matching
+ = extern int regexec(const regex_t *, const char *, size_t, \
+ =					regmatch_t [], int);
+ = #define	REG_NOTBOL	00001
+ = #define	REG_NOTEOL	00002
+ = #define	REG_STARTEND	00004
+ = #define	REG_TRACE	00400	// tracing of execution
+ = #define	REG_LARGE	01000	// force large representation
+ = #define	REG_BACKR	02000	// force use of backref code
+ *
+ * We put this here so we can exploit knowledge of the state representation
+ * when choosing which matcher to call.  Also, by this point the matchers
+ * have been prototyped.
+ */
+int				/* 0 success, REG_NOMATCH failure */
+regexec(const regex_t *preg, const RCHAR_T *string, size_t nmatch, regmatch_t *pmatch, int eflags)
+{
+	register struct re_guts *g = preg->re_g;
+#ifdef REDEBUG
+#	define	GOODFLAGS(f)	(f)
+#else
+#	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
+#endif
+
+	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
+		return(REG_BADPAT);
+	assert(!(g->iflags&BAD));
+	if (g->iflags&BAD)		/* backstop for no-debug case */
+		return(REG_BADPAT);
+	eflags = GOODFLAGS(eflags);
+
+	if (g->nstates <= (int)(CHAR_BIT*sizeof(states1)) && !(eflags&REG_LARGE))
+		return(smatcher(g, string, nmatch, pmatch, eflags));
+	else
+		return(lmatcher(g, string, nmatch, pmatch, eflags));
+}
diff --git a/contrib/nvi/regex/regfree.c b/contrib/nvi/regex/regfree.c
new file mode 100644
index 0000000..61df17c
--- /dev/null
+++ b/contrib/nvi/regex/regfree.c
@@ -0,0 +1,83 @@
+/*	$NetBSD: regfree.c,v 1.2 2009/01/02 00:32:11 tnozaki Exp $ */
+
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)regfree.c	8.2 (Berkeley) 3/16/94
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)regfree.c	8.2 (Berkeley) 3/16/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <regex.h>
+
+#include "utils.h"
+#include "regex2.h"
+
+/*
+ - regfree - free everything
+ = extern void regfree(regex_t *);
+ */
+void
+regfree(regex_t *preg)
+{
+	register struct re_guts *g;
+
+	if (preg->re_magic != MAGIC1)	/* oops */
+		return;			/* nice to complain, but hard */
+
+	g = preg->re_g;
+	if (g == NULL || g->magic != MAGIC2)	/* oops again */
+		return;
+	preg->re_magic = 0;		/* mark it invalid */
+	g->magic = 0;			/* mark it invalid */
+
+	if (g->strip != NULL)
+		free((char *)g->strip);
+	if (g->stripdata != NULL)
+		free((char *)g->stripdata);
+	if (g->sets != NULL)
+		free((char *)g->sets);
+	if (g->setbits != NULL)
+		free((char *)g->setbits);
+	if (g->must != NULL)
+		free(g->must);
+	free((char *)g);
+}
diff --git a/contrib/nvi/regex/utils.h b/contrib/nvi/regex/utils.h
new file mode 100644
index 0000000..4a6f57a
--- /dev/null
+++ b/contrib/nvi/regex/utils.h
@@ -0,0 +1,59 @@
+/*	$NetBSD: utils.h,v 1.1.1.2 2008/05/18 14:31:39 aymeric Exp $ */
+
+/*-
+ * Copyright (c) 1992, 1993, 1994 Henry Spencer.
+ * Copyright (c) 1992, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Henry Spencer of the University of Toronto.
+ *
+ * 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.
+ *
+ *	@(#)utils.h	8.2 (Berkeley) 3/16/94
+ */
+
+/* utility definitions */
+#define	DUPMAX		_POSIX2_RE_DUP_MAX	/* xxx is this right? */
+#define	INFINITY	(DUPMAX + 1)
+#define	NC		(CHAR_MAX - CHAR_MIN + 1)
+typedef unsigned char uch;
+
+/* switch off assertions (if not already off) if no REDEBUG */
+#ifndef REDEBUG
+#ifndef NDEBUG
+#define	NDEBUG	/* no assertions please */
+#endif
+#endif
+#include <assert.h>
+
+/* for old systems with bcopy() but no memmove() */
+#ifdef USEBCOPY
+#define	memmove(d, s, c)	bcopy(s, d, c)
+#endif