Full Code of garyhouston/regexp.old for AI

Repository: garyhouston/regexp.old
Branch: master
Commit: c7db272ecea9
Files: 12
Total size: 51.4 KB

Directory structure:
gitextract_3p4x8yca/

├── COPYRIGHT
├── Makefile
├── README
├── regerror.c
├── regexp.3
├── regexp.c
├── regexp.h
├── regmagic.h
├── regsub.c
├── tests
├── timer.c
└── try.c

================================================
FILE CONTENTS
================================================

================================================
FILE: COPYRIGHT
================================================
Copyright (c) 1986, 1993, 1995 by University of Toronto.
Written by Henry Spencer.  Not derived from licensed software.

Permission is granted to anyone to use this software for any
purpose on any computer system, and to redistribute it in any way,
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 defects in it.

2. The origin of this software must not be misrepresented, either
	by explicit claim or by omission.

3. Altered versions must be plainly marked as such, and must not
	be misrepresented (by explicit claim or omission) as being
	the original software.

4. This notice must not be removed or altered.


================================================
FILE: Makefile
================================================
# Things you might want to put in ENV:
# -DERRAVAIL		have utzoo-compatible error() function and friends
ENV=

# Things you might want to put in TEST:
# -DDEBUG		debugging hooks
# -I.			regexp.h from current directory, not /usr/include
TEST=-I.

# Things you might want to put in PROF:
# -pg			profiler
PROF=

CFLAGS=-O $(ENV) $(TEST) $(PROF)
LDFLAGS=$(PROF)

LIB=libregexp.a
OBJ=regexp.o regsub.o regerror.o
TMP=dtr.tmp

default:	r

try:	try.o $(LIB)
	cc $(LDFLAGS) try.o $(LIB) -o try

# Making timer will probably require putting stuff in $(PROF) and then
# recompiling everything; the following is just the final stage.
timer:	timer.o $(LIB)
	cc $(LDFLAGS) timer.o $(LIB) -o timer

timer.o:	timer.c timer.t.h

timer.t.h:	tests
	sed 's/	/","/g;s/\\/&&/g;s/.*/{"&"},/' tests >timer.t.h

# Regression test.
r:	try tests
	./try <tests		# no news is good news...

$(LIB):	$(OBJ)
	ar cr $(LIB) $(OBJ)

regexp.o:	regexp.c regexp.h regmagic.h
regsub.o:	regsub.c regexp.h regmagic.h

clean:
	rm -f *.o core mon.out gmon.out timer.t.h copy try timer r.*
	rm -f residue rs.* re.1 rm.h re.h ch.soe ch.ps j badcom fig[012]
	rm -f ch.sml fig[12].ps $(LIB)
	rm -rf $(TMP) dtr.*

# the rest of this is unlikely to be of use to you

BITS = r.1 rs.1 re.1 rm.h re.h
OPT=-p -ms

ch.soe:	ch $(BITS)
	soelim ch >$@

ch.sml:	ch $(BITS) smlize splitfigs
	splitfigs ch | soelim | smlize >$@

fig0 fig1 fig2:	ch splitfigs
	splitfigs ch >/dev/null

f:	fig0 fig1 fig2 figs
	groff -Tps -s $(OPT) figs | lpr

fig1.ps:	fig0 fig1
	( cat fig0 ; echo ".LP" ; cat fig1 ) | groff -Tps $(OPT) >$@

fig2.ps:	fig0 fig2
	( cat fig0 ; echo ".LP" ; cat fig2 ) | groff -Tps $(OPT) >$@

fp:	fig1.ps fig2.ps

r.1:	regexp.c splitter
	splitter regexp.c

rs.1:	regsub.c splitter
	splitter regsub.c

re.1:	regerror.c splitter
	splitter regerror.c

rm.h:	regmagic.h splitter
	splitter regmagic.h

re.h:	regexp.h splitter
	splitter regexp.h

PLAIN=COPYRIGHT README Makefile regexp.3 try.c timer.c tests
FIX=regexp.h regexp.c regsub.c regerror.c regmagic.h
DTR=$(PLAIN) $(FIX)

dtr:	r $(DTR)
	rm -rf $(TMP)
	mkdir $(TMP)
	cp $(PLAIN) $(TMP)
	for f in $(FIX) ; do normalize $$f >$(TMP)/$$f ; done
	( cd $(TMP) ; makedtr $(DTR) ) >bookregexp.shar
	( cd $(TMP) ; tar -cvf ../bookregexp.tar $(DTR) )
	rm -rf $(TMP)

ch.ps:	ch Makefile $(BITS)
	groff -Tps $(OPT) ch >$@

copy:	ch.soe ch.sml fp
	makedtr REMARKS ch.sml fig*.ps ch.soe >$@

go:	copy dtr


================================================
FILE: README
================================================
This is a revision of my well-known regular-expression package, regexp(3).
It gives C programs the ability to use egrep-style regular expressions, and
does it in a much cleaner fashion than the analogous routines in SysV.
It is not, alas, fully POSIX.2-compliant; that is hard.  (I'm working on
a full reimplementation that will do that.)

This version is the one which is examined and explained in one chapter of
"Software Solutions in C" (Dale Schumacher, ed.; AP Professional 1994;
ISBN 0-12-632360-7), plus a couple of insignificant updates, plus one
significant bug fix (done 10 Nov 1995).

Although this package was inspired by the Bell V8 regexp(3), this
implementation is *NOT* AT&T/Bell code, and is not derived from licensed
software.  Even though U of T is a V8 licensee.  This software is based on
a V8 manual page sent to me by Dennis Ritchie (the manual page enclosed
here is a complete rewrite and hence is not covered by AT&T copyright).
I admit to some familiarity with regular-expression implementations of
the past, but the only one that this code traces any ancestry to is the
one published in Kernighan & Plauger's "Software Tools" (from which
this one draws ideas but not code).

Simplistically:  put this stuff into a source directory, inspect Makefile
for compilation options that need changing to suit your local environment,
and then do "make".  This compiles the regexp(3) functions, builds a
library containing them, compiles a test program, and runs a large set of
regression tests.  If there are no complaints, then put regexp.h into
/usr/include, add regexp.o, regsub.o, and regerror.o into your C library
(or put libre.a into /usr/lib), and install regexp.3 (perhaps with slight
modifications) in your manual-pages directory. 

The files are:

COPYRIGHT	copyright notice
README		this text
Makefile	instructions to make everything
regexp.3	manual page
regexp.h	header file, for /usr/include
regexp.c	source for regcomp() and regexec()
regsub.c	source for regsub()
regerror.c	source for default regerror()
regmagic.h	internal header file
try.c		source for test program
timer.c		source for timing program
tests		test list for try and timer

This implementation uses nondeterministic automata rather than the
deterministic ones found in some other implementations, which makes it
simpler, smaller, and faster at compiling regular expressions, but slower
at executing them.  Many users have found the speed perfectly adequate,
although replacing the insides of egrep with this code would be a mistake.

This stuff should be pretty portable, given an ANSI C compiler and
appropriate option settings.  There are no "reserved" char values except for
NUL, and no special significance is attached to the top bit of chars.
The string(3) functions are used a fair bit, on the grounds that they are
probably faster than coding the operations in line.  Some attempts at code
tuning have been made, but this is invariably a bit machine-specific.

This distribution lives at ftp://ftp.zoo.toronto.edu/pub/bookregexp.{tar|shar}
at present.


================================================
FILE: regerror.c
================================================
/*
 * regerror
 */
#include <stdio.h>
#include <stdlib.h>

void
regerror(s)
char *s;
{
#ifdef ERRAVAIL
	error("regexp: %s", s);
#else
	fprintf(stderr, "regexp(3): %s\n", s);
	exit(EXIT_FAILURE);
#endif
	/* NOTREACHED */
}


================================================
FILE: regexp.3
================================================
.TH REGEXP 3 "5 Sept 1996"
.SH NAME
regcomp, regexec, regsub, regerror \- regular expression handler
.SH SYNOPSIS
.ft B
.nf
#include <regexp.h>

regexp *regcomp(exp)
const char *exp;

int regexec(prog, string)
regexp *prog;
const char *string;

void regsub(prog, source, dest)
const regexp *prog;
const char *source;
char *dest;

void regerror(msg)
char *msg;
.SH DESCRIPTION
These functions implement
.IR egrep (1)-style
regular expressions and supporting facilities.
.PP
.I Regcomp
compiles a regular expression into a structure of type
.IR regexp ,
and returns a pointer to it.
The space has been allocated using
.IR malloc (3)
and may be released by
.IR free .
.PP
.I Regexec
matches a NUL-terminated \fIstring\fR against the compiled regular expression
in \fIprog\fR.
It returns 1 for success and 0 for failure, and adjusts the contents of
\fIprog\fR's \fIstartp\fR and \fIendp\fR (see below) accordingly.
.PP
The members of a
.I regexp
structure include at least the following (not necessarily in order):
.PP
.RS
char *startp[NSUBEXP];
.br
char *endp[NSUBEXP];
.RE
.PP
where
.I NSUBEXP
is defined (as 10) in the header file.
Once a successful \fIregexec\fR has been done using the \fIregexp\fR,
each \fIstartp\fR-\fIendp\fR pair describes one substring
within the \fIstring\fR,
with the \fIstartp\fR pointing to the first character of the substring and
the \fIendp\fR pointing to the first character following the substring.
The 0th substring is the substring of \fIstring\fR that matched the whole
regular expression.
The others are those substrings that matched parenthesized expressions
within the regular expression, with parenthesized expressions numbered
in left-to-right order of their opening parentheses.
If a parenthesized expression does not participate in the match at all,
its \fIstartp\fR and \fIendp\fR are NULL.
.PP
.I Regsub
copies \fIsource\fR to \fIdest\fR, making substitutions according to the
most recent \fIregexec\fR performed using \fIprog\fR.
Each instance of `&' in \fIsource\fR is replaced by the substring
indicated by \fIstartp\fR[\fI0\fR] and
\fIendp\fR[\fI0\fR].
Each instance of `\e\fIn\fR', where \fIn\fR is a digit, is replaced by
the substring indicated by
\fIstartp\fR[\fIn\fR] and
\fIendp\fR[\fIn\fR].
To get a literal `&' or `\e\fIn\fR' into \fIdest\fR, prefix it with `\e';
to get a literal `\e' preceding `&' or `\e\fIn\fR', prefix it with
another `\e'.
.PP
.I Regerror
is called whenever an error is detected in \fIregcomp\fR, \fIregexec\fR,
or \fIregsub\fR.
The default \fIregerror\fR writes the string \fImsg\fR,
with a suitable indicator of origin,
on the standard
error output
and invokes \fIexit\fR(2).
.I Regerror
can be replaced by the user if other actions are desirable.
.SH "REGULAR EXPRESSION SYNTAX"
A regular expression is zero or more \fIbranches\fR, separated by `|'.
It matches anything that matches one of the branches.
.PP
A branch is zero 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 `*', `+', or `?'.
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 match of the atom, or the null string.
.PP
An atom is a regular expression in parentheses (matching a match for the
regular expression), a \fIrange\fR (see below), `.'
(matching any single character), `^' (matching the null string at the
beginning of the input string), `$' (matching the null string at the
end of the input string), a `\e' followed by a single character (matching
that character), or a single character with no other significance
(matching that character).
.PP
A \fIrange\fR is a sequence of characters enclosed in `[]'.
It normally matches any single character from the sequence.
If the sequence begins with `^',
it matches any single character \fInot\fR from the rest of the sequence.
If two characters in the sequence are separated by `\-', this is shorthand
for the full list of ASCII characters between them
(e.g. `[0-9]' matches any decimal digit).
To include a literal `]' in the sequence, make it the first character
(following a possible `^').
To include a literal `\-', make it the first or last character.
.SH AMBIGUITY
If a regular expression could match two different parts of the input string,
it will match the one which begins earliest.
If both begin in the same place but match different lengths, or match
the same length in different ways, life gets messier, as follows.
.PP
In general, the possibilities in a list of branches are considered in
left-to-right order, the possibilities for `*', `+', and `?' are
considered longest-first, nested constructs are considered from the
outermost in, and concatenated constructs are considered leftmost-first.
The match that will be chosen is the one that uses the earliest
possibility in the first choice that has to be made.
If there is more than one choice, the next will be made in the same manner
(earliest possibility) subject to the decision on the first choice.
And so forth.
.PP
For example, `(ab|a)b*c' could match `abc' in one of two ways.
The first choice is between `ab' and `a'; since `ab' is earlier, and does
lead to a successful overall match, it is chosen.
Since the `b' is already spoken for,
the `b*' must match its last possibility\(emthe empty string\(emsince
it must respect the earlier choice.
.PP
In the particular case where the regular expression does not use `|'
and does not apply `*', `+', or `?' to parenthesized subexpressions,
the net effect is that the longest possible
match will be chosen.
So `ab*', presented with `xabbbby', will match `abbbb'.
Note that if `ab*' is tried against `xabyabbbz', it
will match `ab' just after `x', due to the begins-earliest rule.
(In effect, the decision on where to start the match is the first choice
to be made, hence subsequent choices must respect it even if this leads them
to less-preferred alternatives.)
.SH SEE ALSO
egrep(1), expr(1)
.SH DIAGNOSTICS
\fIRegcomp\fR returns NULL for a failure
(\fIregerror\fR permitting),
where failures are syntax errors, exceeding implementation limits,
or applying `+' or `*' to a possibly-null operand.
.SH HISTORY
This is a revised version.
Both code and manual page were
originally written by Henry Spencer at University of Toronto.
They are intended to be compatible with the Bell V8 \fIregexp\fR(3),
but are not derived from Bell code.
.SH BUGS
Empty branches and empty regular expressions are not portable
to other, otherwise-similar, implementations.
.PP
The ban on
applying `*' or `+' to a possibly-null operand is an artifact of the
simplistic implementation.
.PP
The match-choice rules are complex.
A simple ``longest match'' rule would be preferable,
but is harder to implement.
.PP
Although there is a general similarity to POSIX.2 ``extended'' regular
expressions, neither the regular-expression syntax nor the programming
interface is an exact match.
.PP
Due to emphasis on
compactness and simplicity,
it's not strikingly fast.
It does give some attention to handling simple cases quickly.


================================================
FILE: regexp.c
================================================
/*
 * regcomp and regexec -- regsub and regerror are elsewhere
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <regexp.h>
#include "regmagic.h"

/*
 * The "internal use only" fields in regexp.h are present to pass info from
 * compile to execute that permits the execute phase to run lots faster on
 * simple cases.  They are:
 *
 * regstart	char that must begin a match; '\0' if none obvious
 * reganch	is the match anchored (at beginning-of-line only)?
 * regmust	string (pointer into program) that match must include, or NULL
 * regmlen	length of regmust string
 *
 * Regstart and reganch permit very fast decisions on suitable starting points
 * for a match, cutting down the work a lot.  Regmust permits fast rejection
 * of lines that cannot possibly match.  The regmust tests are costly enough
 * that regcomp() supplies a regmust only if the r.e. contains something
 * potentially expensive (at present, the only such thing detected is * or +
 * at the start of the r.e., which can involve a lot of backup).  Regmlen is
 * supplied because the test in regexec() needs it and regcomp() is computing
 * it anyway.
 */

/*
 * Structure for regexp "program".  This is essentially a linear encoding
 * of a nondeterministic finite-state machine (aka syntax charts or
 * "railroad normal form" in parsing technology).  Each node is an opcode
 * plus a "next" pointer, possibly plus an operand.  "Next" pointers of
 * all nodes except BRANCH implement concatenation; a "next" pointer with
 * a BRANCH on both ends of it is connecting two alternatives.  (Here we
 * have one of the subtle syntax dependencies:  an individual BRANCH (as
 * opposed to a collection of them) is never concatenated with anything
 * because of operator precedence.)  The operand of some types of node is
 * a literal string; for others, it is a node leading into a sub-FSM.  In
 * particular, the operand of a BRANCH node is the first node of the branch.
 * (NB this is *not* a tree structure:  the tail of the branch connects
 * to the thing following the set of BRANCHes.)  The opcodes are:
 */

/* definition	number	opnd?	meaning */
#define	END	0	/* no	End of program. */
#define	BOL	1	/* no	Match beginning of line. */
#define	EOL	2	/* no	Match end of line. */
#define	ANY	3	/* no	Match any character. */
#define	ANYOF	4	/* str	Match any of these. */
#define	ANYBUT	5	/* str	Match any but one of these. */
#define	BRANCH	6	/* node	Match this, or the next..\&. */
#define	BACK	7	/* no	"next" ptr points backward. */
#define	EXACTLY	8	/* str	Match this string. */
#define	NOTHING	9	/* no	Match empty string. */
#define	STAR	10	/* node	Match this 0 or more times. */
#define	PLUS	11	/* node	Match this 1 or more times. */
#define	OPEN	20	/* no	Sub-RE starts here. */
			/*	OPEN+1 is number 1, etc. */
#define	CLOSE	30	/* no	Analogous to OPEN. */

/*
 * Opcode notes:
 *
 * BRANCH	The set of branches constituting a single choice are hooked
 *		together with their "next" pointers, since precedence prevents
 *		anything being concatenated to any individual branch.  The
 *		"next" pointer of the last BRANCH in a choice points to the
 *		thing following the whole choice.  This is also where the
 *		final "next" pointer of each individual branch points; each
 *		branch starts with the operand node of a BRANCH node.
 *
 * BACK		Normal "next" pointers all implicitly point forward; BACK
 *		exists to make loop structures possible.
 *
 * STAR,PLUS	'?', and complex '*' and '+', are implemented as circular
 *		BRANCH structures using BACK.  Simple cases (one character
 *		per match) are implemented with STAR and PLUS for speed
 *		and to minimize recursive plunges.
 *
 * OPEN,CLOSE	...are numbered at compile time.
 */

/*
 * A node is one char of opcode followed by two chars of "next" pointer.
 * "Next" pointers are stored as two 8-bit pieces, high order first.  The
 * value is a positive offset from the opcode of the node containing it.
 * An operand, if any, simply follows the node.  (Note that much of the
 * code generation knows about this implicit relationship.)
 *
 * Using two bytes for the "next" pointer is vast overkill for most things,
 * but allows patterns to get big without disasters.
 */
#define	OP(p)		(*(p))
#define	NEXT(p)		(((*((p)+1)&0177)<<8) + (*((p)+2)&0377))
#define	OPERAND(p)	((p) + 3)

/*
 * See regmagic.h for one further detail of program structure.
 */


/*
 * Utility definitions.
 */
#define	FAIL(m)		{ regerror(m); return(NULL); }
#define	ISREPN(c)	((c) == '*' || (c) == '+' || (c) == '?')
#define	META		"^$.[()|?+*\\"

/*
 * Flags to be passed up and down.
 */
#define	HASWIDTH	01	/* Known never to match null string. */
#define	SIMPLE		02	/* Simple enough to be STAR/PLUS operand. */
#define	SPSTART		04	/* Starts with * or +. */
#define	WORST		0	/* Worst case. */

/*
 * Work-variable struct for regcomp().
 */
struct comp {
	char *regparse;		/* Input-scan pointer. */
	int regnpar;		/* () count. */
	char *regcode;		/* Code-emit pointer; &regdummy = don't. */
	char regdummy[3];	/* NOTHING, 0 next ptr */
	long regsize;		/* Code size. */
};
#define	EMITTING(cp)	((cp)->regcode != (cp)->regdummy)

/*
 * Forward declarations for regcomp()'s friends.
 */
static char *reg(struct comp *cp, int paren, int *flagp);
static char *regbranch(struct comp *cp, int *flagp);
static char *regpiece(struct comp *cp, int *flagp);
static char *regatom(struct comp *cp, int *flagp);
static char *regnode(struct comp *cp, int op);
static char *regnext(char *node);
static void regc(struct comp *cp, int c);
static void reginsert(struct comp *cp, int op, char *opnd);
static void regtail(struct comp *cp, char *p, char *val);
static void regoptail(struct comp *cp, char *p, char *val);

/*
 - regcomp - compile a regular expression into internal code
 *
 * We can't allocate space until we know how big the compiled form will be,
 * but we can't compile it (and thus know how big it is) until we've got a
 * place to put the code.  So we cheat:  we compile it twice, once with code
 * generation turned off and size counting turned on, and once "for real".
 * This also means that we don't allocate space until we are sure that the
 * thing really will compile successfully, and we never have to move the
 * code and thus invalidate pointers into it.  (Note that it has to be in
 * one piece because free() must be able to free it all.)
 *
 * Beware that the optimization-preparation code in here knows about some
 * of the structure of the compiled regexp.
 */
regexp *
regcomp(exp)
const char *exp;
{
	register regexp *r;
	register char *scan;
	int flags;
	struct comp co;

	if (exp == NULL)
		FAIL("NULL argument to regcomp");

	/* First pass: determine size, legality. */
	co.regparse = (char *)exp;
	co.regnpar = 1;
	co.regsize = 0L;
	co.regdummy[0] = NOTHING;
	co.regdummy[1] = co.regdummy[2] = 0;
	co.regcode = co.regdummy;
	regc(&co, MAGIC);
	if (reg(&co, 0, &flags) == NULL)
		return(NULL);

	/* Small enough for pointer-storage convention? */
	if (co.regsize >= 0x7fffL)	/* Probably could be 0xffffL. */
		FAIL("regexp too big");

	/* Allocate space. */
	r = (regexp *)malloc(sizeof(regexp) + (size_t)co.regsize);
	if (r == NULL)
		FAIL("out of space");

	/* Second pass: emit code. */
	co.regparse = (char *)exp;
	co.regnpar = 1;
	co.regcode = r->program;
	regc(&co, MAGIC);
	if (reg(&co, 0, &flags) == NULL)
		return(NULL);

	/* Dig out information for optimizations. */
	r->regstart = '\0';		/* Worst-case defaults. */
	r->reganch = 0;
	r->regmust = NULL;
	r->regmlen = 0;
	scan = r->program+1;		/* First BRANCH. */
	if (OP(regnext(scan)) == END) {	/* Only one top-level choice. */
		scan = OPERAND(scan);

		/* Starting-point info. */
		if (OP(scan) == EXACTLY)
			r->regstart = *OPERAND(scan);
		else if (OP(scan) == BOL)
			r->reganch = 1;

		/*
		 * If there's something expensive in the r.e., find the
		 * longest literal string that must appear and make it the
		 * regmust.  Resolve ties in favor of later strings, since
		 * the regstart check works with the beginning of the r.e.
		 * and avoiding duplication strengthens checking.  Not a
		 * strong reason, but sufficient in the absence of others.
		 */
		if (flags&SPSTART) {
			register char *longest = NULL;
			register size_t len = 0;

			for (; scan != NULL; scan = regnext(scan))
				if (OP(scan) == EXACTLY && strlen(OPERAND(scan)) >= len) {
					longest = OPERAND(scan);
					len = strlen(OPERAND(scan));
				}
			r->regmust = longest;
			r->regmlen = (int)len;
		}
	}

	return(r);
}

/*
 - reg - regular expression, i.e. main body or parenthesized thing
 *
 * Caller must absorb opening parenthesis.
 *
 * Combining parenthesis handling with the base level of regular expression
 * is a trifle forced, but the need to tie the tails of the branches to what
 * follows makes it hard to avoid.
 */
static char *
reg(cp, paren, flagp)
register struct comp *cp;
int paren;			/* Parenthesized? */
int *flagp;
{
	register char *ret;
	register char *br;
	register char *ender;
	register int parno;
	int flags;

	*flagp = HASWIDTH;	/* Tentatively. */

	if (paren) {
		/* Make an OPEN node. */
		if (cp->regnpar >= NSUBEXP)
			FAIL("too many ()");
		parno = cp->regnpar;
		cp->regnpar++;
		ret = regnode(cp, OPEN+parno);
	}

	/* Pick up the branches, linking them together. */
	br = regbranch(cp, &flags);
	if (br == NULL)
		return(NULL);
	if (paren)
		regtail(cp, ret, br);	/* OPEN -> first. */
	else
		ret = br;
	*flagp &= ~(~flags&HASWIDTH);	/* Clear bit if bit 0. */
	*flagp |= flags&SPSTART;
	while (*cp->regparse == '|') {
		cp->regparse++;
		br = regbranch(cp, &flags);
		if (br == NULL)
			return(NULL);
		regtail(cp, ret, br);	/* BRANCH -> BRANCH. */
		*flagp &= ~(~flags&HASWIDTH);
		*flagp |= flags&SPSTART;
	}

	/* Make a closing node, and hook it on the end. */
	ender = regnode(cp, (paren) ? CLOSE+parno : END);
	regtail(cp, ret, ender);

	/* Hook the tails of the branches to the closing node. */
	for (br = ret; br != NULL; br = regnext(br))
		regoptail(cp, br, ender);

	/* Check for proper termination. */
	if (paren && *cp->regparse++ != ')') {
		FAIL("unterminated ()");
	} else if (!paren && *cp->regparse != '\0') {
		if (*cp->regparse == ')') {
			FAIL("unmatched ()");
		} else
			FAIL("internal error: junk on end");
		/* NOTREACHED */
	}

	return(ret);
}

/*
 - regbranch - one alternative of an | operator
 *
 * Implements the concatenation operator.
 */
static char *
regbranch(cp, flagp)
register struct comp *cp;
int *flagp;
{
	register char *ret;
	register char *chain;
	register char *latest;
	int flags;
	register int c;

	*flagp = WORST;				/* Tentatively. */

	ret = regnode(cp, BRANCH);
	chain = NULL;
	while ((c = *cp->regparse) != '\0' && c != '|' && c != ')') {
		latest = regpiece(cp, &flags);
		if (latest == NULL)
			return(NULL);
		*flagp |= flags&HASWIDTH;
		if (chain == NULL)		/* First piece. */
			*flagp |= flags&SPSTART;
		else
			regtail(cp, chain, latest);
		chain = latest;
	}
	if (chain == NULL)			/* Loop ran zero times. */
		(void) regnode(cp, NOTHING);

	return(ret);
}

/*
 - regpiece - something followed by possible [*+?]
 *
 * Note that the branching code sequences used for ? and the general cases
 * of * and + are somewhat optimized:  they use the same NOTHING node as
 * both the endmarker for their branch list and the body of the last branch.
 * It might seem that this node could be dispensed with entirely, but the
 * endmarker role is not redundant.
 */
static char *
regpiece(cp, flagp)
register struct comp *cp;
int *flagp;
{
	register char *ret;
	register char op;
	register char *next;
	int flags;

	ret = regatom(cp, &flags);
	if (ret == NULL)
		return(NULL);

	op = *cp->regparse;
	if (!ISREPN(op)) {
		*flagp = flags;
		return(ret);
	}

	if (!(flags&HASWIDTH) && op != '?')
		FAIL("*+ operand could be empty");
	switch (op) {
	case '*':	*flagp = WORST|SPSTART;			break;
	case '+':	*flagp = WORST|SPSTART|HASWIDTH;	break;
	case '?':	*flagp = WORST;				break;
	}

	if (op == '*' && (flags&SIMPLE))
		reginsert(cp, STAR, ret);
	else if (op == '*') {
		/* Emit x* as (x&|), where & means "self". */
		reginsert(cp, BRANCH, ret);		/* Either x */
		regoptail(cp, ret, regnode(cp, BACK));	/* and loop */
		regoptail(cp, ret, ret);		/* back */
		regtail(cp, ret, regnode(cp, BRANCH));	/* or */
		regtail(cp, ret, regnode(cp, NOTHING));	/* null. */
	} else if (op == '+' && (flags&SIMPLE))
		reginsert(cp, PLUS, ret);
	else if (op == '+') {
		/* Emit x+ as x(&|), where & means "self". */
		next = regnode(cp, BRANCH);		/* Either */
		regtail(cp, ret, next);
		regtail(cp, regnode(cp, BACK), ret);	/* loop back */
		regtail(cp, next, regnode(cp, BRANCH));	/* or */
		regtail(cp, ret, regnode(cp, NOTHING));	/* null. */
	} else if (op == '?') {
		/* Emit x? as (x|) */
		reginsert(cp, BRANCH, ret);		/* Either x */
		regtail(cp, ret, regnode(cp, BRANCH));	/* or */
		next = regnode(cp, NOTHING);		/* null. */
		regtail(cp, ret, next);
		regoptail(cp, ret, next);
	}
	cp->regparse++;
	if (ISREPN(*cp->regparse))
		FAIL("nested *?+");

	return(ret);
}

/*
 - regatom - the lowest level
 *
 * Optimization:  gobbles an entire sequence of ordinary characters so that
 * it can turn them into a single node, which is smaller to store and
 * faster to run.  Backslashed characters are exceptions, each becoming a
 * separate node; the code is simpler that way and it's not worth fixing.
 */
static char *
regatom(cp, flagp)
register struct comp *cp;
int *flagp;
{
	register char *ret;
	int flags;

	*flagp = WORST;		/* Tentatively. */

	switch (*cp->regparse++) {
	case '^':
		ret = regnode(cp, BOL);
		break;
	case '$':
		ret = regnode(cp, EOL);
		break;
	case '.':
		ret = regnode(cp, ANY);
		*flagp |= HASWIDTH|SIMPLE;
		break;
	case '[': {
		register int range;
		register int rangeend;
		register int c;

		if (*cp->regparse == '^') {	/* Complement of range. */
			ret = regnode(cp, ANYBUT);
			cp->regparse++;
		} else
			ret = regnode(cp, ANYOF);
		if ((c = *cp->regparse) == ']' || c == '-') {
			regc(cp, c);
			cp->regparse++;
		}
		while ((c = *cp->regparse++) != '\0' && c != ']') {
			if (c != '-')
				regc(cp, c);
			else if ((c = *cp->regparse) == ']' || c == '\0')
				regc(cp, '-');
			else {
				range = (unsigned char)*(cp->regparse-2);
				rangeend = (unsigned char)c;
				if (range > rangeend)
					FAIL("invalid [] range");
				for (range++; range <= rangeend; range++)
					regc(cp, range);
				cp->regparse++;
			}
		}
		regc(cp, '\0');
		if (c != ']')
			FAIL("unmatched []");
		*flagp |= HASWIDTH|SIMPLE;
		break;
		}
	case '(':
		ret = reg(cp, 1, &flags);
		if (ret == NULL)
			return(NULL);
		*flagp |= flags&(HASWIDTH|SPSTART);
		break;
	case '\0':
	case '|':
	case ')':
		/* supposed to be caught earlier */
		FAIL("internal error: \\0|) unexpected");
		break;
	case '?':
	case '+':
	case '*':
		FAIL("?+* follows nothing");
		break;
	case '\\':
		if (*cp->regparse == '\0')
			FAIL("trailing \\");
		ret = regnode(cp, EXACTLY);
		regc(cp, *cp->regparse++);
		regc(cp, '\0');
		*flagp |= HASWIDTH|SIMPLE;
		break;
	default: {
		register size_t len;
		register char ender;

		cp->regparse--;
		len = strcspn(cp->regparse, META);
		if (len == 0)
			FAIL("internal error: strcspn 0");
		ender = *(cp->regparse+len);
		if (len > 1 && ISREPN(ender))
			len--;		/* Back off clear of ?+* operand. */
		*flagp |= HASWIDTH;
		if (len == 1)
			*flagp |= SIMPLE;
		ret = regnode(cp, EXACTLY);
		for (; len > 0; len--)
			regc(cp, *cp->regparse++);
		regc(cp, '\0');
		break;
		}
	}

	return(ret);
}

/*
 - regnode - emit a node
 */
static char *			/* Location. */
regnode(cp, op)
register struct comp *cp;
char op;
{
	register char *const ret = cp->regcode;
	register char *ptr;

	if (!EMITTING(cp)) {
		cp->regsize += 3;
		return(ret);
	}

	ptr = ret;
	*ptr++ = op;
	*ptr++ = '\0';		/* Null next pointer. */
	*ptr++ = '\0';
	cp->regcode = ptr;

	return(ret);
}

/*
 - regc - emit (if appropriate) a byte of code
 */
static void
regc(cp, b)
register struct comp *cp;
char b;
{
	if (EMITTING(cp))
		*cp->regcode++ = b;
	else
		cp->regsize++;
}

/*
 - reginsert - insert an operator in front of already-emitted operand
 *
 * Means relocating the operand.
 */
static void
reginsert(cp, op, opnd)
register struct comp *cp;
char op;
char *opnd;
{
	register char *place;

	if (!EMITTING(cp)) {
		cp->regsize += 3;
		return;
	}

	(void) memmove(opnd+3, opnd, (size_t)(cp->regcode - opnd));
	cp->regcode += 3;

	place = opnd;		/* Op node, where operand used to be. */
	*place++ = op;
	*place++ = '\0';
	*place++ = '\0';
}

/*
 - regtail - set the next-pointer at the end of a node chain
 */
static void
regtail(cp, p, val)
register struct comp *cp;
char *p;
char *val;
{
	register char *scan;
	register char *temp;
	register int offset;

	if (!EMITTING(cp))
		return;

	/* Find last node. */
	for (scan = p; (temp = regnext(scan)) != NULL; scan = temp)
		continue;

	offset = (OP(scan) == BACK) ? scan - val : val - scan;
	*(scan+1) = (offset>>8)&0177;
	*(scan+2) = offset&0377;
}

/*
 - regoptail - regtail on operand of first argument; nop if operandless
 */
static void
regoptail(cp, p, val)
register struct comp *cp;
char *p;
char *val;
{
	/* "Operandless" and "op != BRANCH" are synonymous in practice. */
	if (!EMITTING(cp) || OP(p) != BRANCH)
		return;
	regtail(cp, OPERAND(p), val);
}

/*
 * regexec and friends
 */

/*
 * Work-variable struct for regexec().
 */
struct exec {
	char *reginput;		/* String-input pointer. */
	char *regbol;		/* Beginning of input, for ^ check. */
	char **regstartp;	/* Pointer to startp array. */
	char **regendp;		/* Ditto for endp. */
};

/*
 * Forwards.
 */
static int regtry(struct exec *ep, regexp *rp, char *string);
static int regmatch(struct exec *ep, char *prog);
static size_t regrepeat(struct exec *ep, char *node);

#ifdef DEBUG
int regnarrate = 0;
void regdump();
static char *regprop();
#endif

/*
 - regexec - match a regexp against a string
 */
int
regexec(prog, str)
register regexp *prog;
const char *str;
{
	register char *string = (char *)str;	/* avert const poisoning */
	register char *s;
	struct exec ex;

	/* Be paranoid. */
	if (prog == NULL || string == NULL) {
		regerror("NULL argument to regexec");
		return(0);
	}

	/* Check validity of program. */
	if ((unsigned char)*prog->program != MAGIC) {
		regerror("corrupted regexp");
		return(0);
	}

	/* If there is a "must appear" string, look for it. */
	if (prog->regmust != NULL && strstr(string, prog->regmust) == NULL)
		return(0);

	/* Mark beginning of line for ^ . */
	ex.regbol = string;
	ex.regstartp = prog->startp;
	ex.regendp = prog->endp;

	/* Simplest case:  anchored match need be tried only once. */
	if (prog->reganch)
		return(regtry(&ex, prog, string));

	/* Messy cases:  unanchored match. */
	if (prog->regstart != '\0') {
		/* We know what char it must start with. */
		for (s = string; s != NULL; s = strchr(s+1, prog->regstart))
			if (regtry(&ex, prog, s))
				return(1);
		return(0);
	} else {
		/* We don't -- general case. */
		for (s = string; !regtry(&ex, prog, s); s++)
			if (*s == '\0')
				return(0);
		return(1);
	}
	/* NOTREACHED */
}

/*
 - regtry - try match at specific point
 */
static int			/* 0 failure, 1 success */
regtry(ep, prog, string)
register struct exec *ep;
regexp *prog;
char *string;
{
	register int i;
	register char **stp;
	register char **enp;

	ep->reginput = string;

	stp = prog->startp;
	enp = prog->endp;
	for (i = NSUBEXP; i > 0; i--) {
		*stp++ = NULL;
		*enp++ = NULL;
	}
	if (regmatch(ep, prog->program + 1)) {
		prog->startp[0] = string;
		prog->endp[0] = ep->reginput;
		return(1);
	} else
		return(0);
}

/*
 - regmatch - main matching routine
 *
 * Conceptually the strategy is simple:  check to see whether the current
 * node matches, call self recursively to see whether the rest matches,
 * and then act accordingly.  In practice we make some effort to avoid
 * recursion, in particular by going through "ordinary" nodes (that don't
 * need to know whether the rest of the match failed) by a loop instead of
 * by recursion.
 */
static int			/* 0 failure, 1 success */
regmatch(ep, prog)
register struct exec *ep;
char *prog;
{
	register char *scan;	/* Current node. */
	char *next;		/* Next node. */

#ifdef DEBUG
	if (prog != NULL && regnarrate)
		fprintf(stderr, "%s(\n", regprop(prog));
#endif
	for (scan = prog; scan != NULL; scan = next) {
#ifdef DEBUG
		if (regnarrate)
			fprintf(stderr, "%s...\n", regprop(scan));
#endif
		next = regnext(scan);

		switch (OP(scan)) {
		case BOL:
			if (ep->reginput != ep->regbol)
				return(0);
			break;
		case EOL:
			if (*ep->reginput != '\0')
				return(0);
			break;
		case ANY:
			if (*ep->reginput == '\0')
				return(0);
			ep->reginput++;
			break;
		case EXACTLY: {
			register size_t len;
			register char *const opnd = OPERAND(scan);

			/* Inline the first character, for speed. */
			if (*opnd != *ep->reginput)
				return(0);
			len = strlen(opnd);
			if (len > 1 && strncmp(opnd, ep->reginput, len) != 0)
				return(0);
			ep->reginput += len;
			break;
			}
		case ANYOF:
			if (*ep->reginput == '\0' ||
					strchr(OPERAND(scan), *ep->reginput) == NULL)
				return(0);
			ep->reginput++;
			break;
		case ANYBUT:
			if (*ep->reginput == '\0' ||
					strchr(OPERAND(scan), *ep->reginput) != NULL)
				return(0);
			ep->reginput++;
			break;
		case NOTHING:
			break;
		case BACK:
			break;
		case OPEN+1: case OPEN+2: case OPEN+3:
		case OPEN+4: case OPEN+5: case OPEN+6:
		case OPEN+7: case OPEN+8: case OPEN+9: {
			register const int no = OP(scan) - OPEN;
			register char *const input = ep->reginput;

			if (regmatch(ep, next)) {
				/*
				 * Don't set startp if some later
				 * invocation of the same parentheses
				 * already has.
				 */
				if (ep->regstartp[no] == NULL)
					ep->regstartp[no] = input;
				return(1);
			} else
				return(0);
			break;
			}
		case CLOSE+1: case CLOSE+2: case CLOSE+3:
		case CLOSE+4: case CLOSE+5: case CLOSE+6:
		case CLOSE+7: case CLOSE+8: case CLOSE+9: {
			register const int no = OP(scan) - CLOSE;
			register char *const input = ep->reginput;

			if (regmatch(ep, next)) {
				/*
				 * Don't set endp if some later
				 * invocation of the same parentheses
				 * already has.
				 */
				if (ep->regendp[no] == NULL)
					ep->regendp[no] = input;
				return(1);
			} else
				return(0);
			break;
			}
		case BRANCH: {
			register char *const save = ep->reginput;

			if (OP(next) != BRANCH)		/* No choice. */
				next = OPERAND(scan);	/* Avoid recursion. */
			else {
				while (OP(scan) == BRANCH) {
					if (regmatch(ep, OPERAND(scan)))
						return(1);
					ep->reginput = save;
					scan = regnext(scan);
				}
				return(0);
				/* NOTREACHED */
			}
			break;
			}
		case STAR: case PLUS: {
			register const char nextch =
				(OP(next) == EXACTLY) ? *OPERAND(next) : '\0';
			register size_t no;
			register char *const save = ep->reginput;
			register const size_t min = (OP(scan) == STAR) ? 0 : 1;

			for (no = regrepeat(ep, OPERAND(scan)) + 1; no > min; no--) {
				ep->reginput = save + no - 1;
				/* If it could work, try it. */
				if (nextch == '\0' || *ep->reginput == nextch)
					if (regmatch(ep, next))
						return(1);
			}
			return(0);
			break;
			}
		case END:
			return(1);	/* Success! */
			break;
		default:
			regerror("regexp corruption");
			return(0);
			break;
		}
	}

	/*
	 * We get here only if there's trouble -- normally "case END" is
	 * the terminating point.
	 */
	regerror("corrupted pointers");
	return(0);
}

/*
 - regrepeat - report how many times something simple would match
 */
static size_t
regrepeat(ep, node)
register struct exec *ep;
char *node;
{
	register size_t count;
	register char *scan;
	register char ch;

	switch (OP(node)) {
	case ANY:
		return(strlen(ep->reginput));
		break;
	case EXACTLY:
		ch = *OPERAND(node);
		count = 0;
		for (scan = ep->reginput; *scan == ch; scan++)
			count++;
		return(count);
		break;
	case ANYOF:
		return(strspn(ep->reginput, OPERAND(node)));
		break;
	case ANYBUT:
		return(strcspn(ep->reginput, OPERAND(node)));
		break;
	default:		/* Oh dear.  Called inappropriately. */
		regerror("internal error: bad call of regrepeat");
		return(0);	/* Best compromise. */
		break;
	}
	/* NOTREACHED */
}

/*
 - regnext - dig the "next" pointer out of a node
 */
static char *
regnext(p)
register char *p;
{
	register const int offset = NEXT(p);

	if (offset == 0)
		return(NULL);

	return((OP(p) == BACK) ? p-offset : p+offset);
}

#ifdef DEBUG

static char *regprop();

/*
 - regdump - dump a regexp onto stdout in vaguely comprehensible form
 */
void
regdump(r)
regexp *r;
{
	register char *s;
	register char op = EXACTLY;	/* Arbitrary non-END op. */
	register char *next;


	s = r->program + 1;
	while (op != END) {	/* While that wasn't END last time... */
		op = OP(s);
		printf("%2d%s", s-r->program, regprop(s));	/* Where, what. */
		next = regnext(s);
		if (next == NULL)		/* Next ptr. */
			printf("(0)");
		else 
			printf("(%d)", (s-r->program)+(next-s));
		s += 3;
		if (op == ANYOF || op == ANYBUT || op == EXACTLY) {
			/* Literal string, where present. */
			while (*s != '\0') {
				putchar(*s);
				s++;
			}
			s++;
		}
		putchar('\n');
	}

	/* Header fields of interest. */
	if (r->regstart != '\0')
		printf("start `%c' ", r->regstart);
	if (r->reganch)
		printf("anchored ");
	if (r->regmust != NULL)
		printf("must have \"%s\"", r->regmust);
	printf("\n");
}

/*
 - regprop - printable representation of opcode
 */
static char *
regprop(op)
char *op;
{
	register char *p;
	static char buf[50];

	(void) strcpy(buf, ":");

	switch (OP(op)) {
	case BOL:
		p = "BOL";
		break;
	case EOL:
		p = "EOL";
		break;
	case ANY:
		p = "ANY";
		break;
	case ANYOF:
		p = "ANYOF";
		break;
	case ANYBUT:
		p = "ANYBUT";
		break;
	case BRANCH:
		p = "BRANCH";
		break;
	case EXACTLY:
		p = "EXACTLY";
		break;
	case NOTHING:
		p = "NOTHING";
		break;
	case BACK:
		p = "BACK";
		break;
	case END:
		p = "END";
		break;
	case OPEN+1:
	case OPEN+2:
	case OPEN+3:
	case OPEN+4:
	case OPEN+5:
	case OPEN+6:
	case OPEN+7:
	case OPEN+8:
	case OPEN+9:
		sprintf(buf+strlen(buf), "OPEN%d", OP(op)-OPEN);
		p = NULL;
		break;
	case CLOSE+1:
	case CLOSE+2:
	case CLOSE+3:
	case CLOSE+4:
	case CLOSE+5:
	case CLOSE+6:
	case CLOSE+7:
	case CLOSE+8:
	case CLOSE+9:
		sprintf(buf+strlen(buf), "CLOSE%d", OP(op)-CLOSE);
		p = NULL;
		break;
	case STAR:
		p = "STAR";
		break;
	case PLUS:
		p = "PLUS";
		break;
	default:
		regerror("corrupted opcode");
		break;
	}
	if (p != NULL)
		(void) strcat(buf, p);
	return(buf);
}
#endif


================================================
FILE: regexp.h
================================================
/*
 * Definitions etc. for regexp(3) routines.
 *
 * Caveat:  this is V8 regexp(3) [actually, a reimplementation thereof],
 * not the System V one.
 */
#define NSUBEXP  10
typedef struct regexp {
	char *startp[NSUBEXP];
	char *endp[NSUBEXP];
	char regstart;		/* Internal use only. */
	char reganch;		/* Internal use only. */
	char *regmust;		/* Internal use only. */
	int regmlen;		/* Internal use only. */
	char program[1];	/* Unwarranted chumminess with compiler. */
} regexp;

extern regexp *regcomp(const char *re);
extern int regexec(regexp *rp, const char *s);
extern void regsub(const regexp *rp, const char *src, char *dst);
extern void regerror(char *message);


================================================
FILE: regmagic.h
================================================
/*
 * The first byte of the regexp internal "program" is actually this magic
 * number; the start node begins in the second byte.
 */
#define	MAGIC	0234


================================================
FILE: regsub.c
================================================
/*
 * regsub
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <regexp.h>
#include "regmagic.h"

/*
 - regsub - perform substitutions after a regexp match
 */
void
regsub(rp, source, dest)
const regexp *rp;
const char *source;
char *dest;
{
	register regexp * const prog = (regexp *)rp;
	register char *src = (char *)source;
	register char *dst = dest;
	register char c;
	register int no;
	register size_t len;

	if (prog == NULL || source == NULL || dest == NULL) {
		regerror("NULL parameter to regsub");
		return;
	}
	if ((unsigned char)*(prog->program) != MAGIC) {
		regerror("damaged regexp");
		return;
	}

	while ((c = *src++) != '\0') {
		if (c == '&')
			no = 0;
		else if (c == '\\' && isdigit(*src))
			no = *src++ - '0';
		else
			no = -1;

		if (no < 0) {	/* Ordinary character. */
			if (c == '\\' && (*src == '\\' || *src == '&'))
				c = *src++;
			*dst++ = c;
		} else if (prog->startp[no] != NULL && prog->endp[no] != NULL &&
					prog->endp[no] > prog->startp[no]) {
			len = prog->endp[no] - prog->startp[no];
			(void) strncpy(dst, prog->startp[no], len);
			dst += len;
			if (*(dst-1) == '\0') {	/* strncpy hit NUL. */
				regerror("damaged match string");
				return;
			}
		}
	}
	*dst++ = '\0';
}


================================================
FILE: tests
================================================
abc	abc	y	&	abc
abc	xbc	n	-	-
abc	axc	n	-	-
abc	abx	n	-	-
abc	xabcy	y	&	abc
abc	ababc	y	&	abc
ab*c	abc	y	&	abc
ab*bc	abc	y	&	abc
ab*bc	abbc	y	&	abbc
ab*bc	abbbbc	y	&	abbbbc
ab+bc	abbc	y	&	abbc
ab+bc	abc	n	-	-
ab+bc	abq	n	-	-
ab+bc	abbbbc	y	&	abbbbc
ab?bc	abbc	y	&	abbc
ab?bc	abc	y	&	abc
ab?bc	abbbbc	n	-	-
ab?c	abc	y	&	abc
^abc$	abc	y	&	abc
^abc$	abcc	n	-	-
^abc	abcc	y	&	abc
^abc$	aabc	n	-	-
abc$	aabc	y	&	abc
^	abc	y	&	
$	abc	y	&	
a.c	abc	y	&	abc
a.c	axc	y	&	axc
a.*c	axyzc	y	&	axyzc
a.*c	axyzd	n	-	-
a[bc]d	abc	n	-	-
a[bc]d	abd	y	&	abd
a[b-d]e	abd	n	-	-
a[b-d]e	ace	y	&	ace
a[b-d]	aac	y	&	ac
a[-b]	a-	y	&	a-
a[b-]	a-	y	&	a-
[k]	ab	n	-	-
a[b-a]	-	c	-	-
a[]b	-	c	-	-
a[	-	c	-	-
a]	a]	y	&	a]
a[]]b	a]b	y	&	a]b
a[^bc]d	aed	y	&	aed
a[^bc]d	abd	n	-	-
a[^-b]c	adc	y	&	adc
a[^-b]c	a-c	n	-	-
a[^]b]c	a]c	n	-	-
a[^]b]c	adc	y	&	adc
ab|cd	abc	y	&	ab
ab|cd	abcd	y	&	ab
()ef	def	y	&-\1	ef-
()*	-	c	-	-
*a	-	c	-	-
^*	-	c	-	-
$*	-	c	-	-
(*)b	-	c	-	-
$b	b	n	-	-
a\	-	c	-	-
a\(b	a(b	y	&-\1	a(b-
a\(*b	ab	y	&	ab
a\(*b	a((b	y	&	a((b
a\\b	a\b	y	&	a\b
abc)	-	c	-	-
(abc	-	c	-	-
((a))	abc	y	&-\1-\2	a-a-a
(a)b(c)	abc	y	&-\1-\2	abc-a-c
a+b+c	aabbabc	y	&	abc
a**	-	c	-	-
a*?	-	c	-	-
(a*)*	-	c	-	-
(a*)+	-	c	-	-
(a|)*	-	c	-	-
(a*|b)*	-	c	-	-
(a+|b)*	ab	y	&-\1	ab-b
(a+|b)+	ab	y	&-\1	ab-b
(a+|b)?	ab	y	&-\1	a-a
[^ab]*	cde	y	&	cde
(^)*	-	c	-	-
(ab|)*	-	c	-	-
)(	-	c	-	-
	abc	y	&	
abc		n	-	-
a*		y	&	
abcd	abcd	y	&-\&-\\&	abcd-&-\abcd
a(bc)d	abcd	y	\1-\\1-\\\1	bc-\1-\bc
([abc])*d	abbbcd	y	&-\1	abbbcd-c
([abc])*bcd	abcd	y	&-\1	abcd-a
a|b|c|d|e	e	y	&	e
(a|b|c|d|e)f	ef	y	&-\1	ef-e
((a*|b))*	-	c	-	-
abcd*efg	abcdefg	y	&	abcdefg
ab*	xabyabbbz	y	&	ab
ab*	xayabbbz	y	&	a
(ab|cd)e	abcde	y	&-\1	cde-cd
[abhgefdc]ij	hij	y	&	hij
^(ab|cd)e	abcde	n	x\1y	xy
(abc|)ef	abcdef	y	&-\1	ef-
(a|b)c*d	abcd	y	&-\1	bcd-b
(ab|ab*)bc	abc	y	&-\1	abc-a
a([bc]*)c*	abc	y	&-\1	abc-bc
a([bc]*)(c*d)	abcd	y	&-\1-\2	abcd-bc-d
a([bc]+)(c*d)	abcd	y	&-\1-\2	abcd-bc-d
a([bc]*)(c+d)	abcd	y	&-\1-\2	abcd-b-cd
a[bcd]*dcdcde	adcdcde	y	&	adcdcde
a[bcd]+dcdcde	adcdcde	n	-	-
(ab|a)b*c	abc	y	&-\1	abc-ab
((a)(b)c)(d)	abcd	y	\1-\2-\3-\4	abc-a-b-d
[ -~]*	abc	y	&	abc
[ -~ -~]*	abc	y	&	abc
[ -~ -~ -~]*	abc	y	&	abc
[ -~ -~ -~ -~]*	abc	y	&	abc
[ -~ -~ -~ -~ -~]*	abc	y	&	abc
[ -~ -~ -~ -~ -~ -~]*	abc	y	&	abc
[ -~ -~ -~ -~ -~ -~ -~]*	abc	y	&	abc
[a-zA-Z_][a-zA-Z0-9_]*	alpha	y	&	alpha
^a(bc+|b[eh])g|.h$	abh	y	&-\1	bh-
(bc+d$|ef*g.|h?i(j|k))	effgz	y	&-\1-\2	effgz-effgz-
(bc+d$|ef*g.|h?i(j|k))	ij	y	&-\1-\2	ij-ij-j
(bc+d$|ef*g.|h?i(j|k))	effg	n	-	-
(bc+d$|ef*g.|h?i(j|k))	bcdd	n	-	-
(bc+d$|ef*g.|h?i(j|k))	reffgz	y	&-\1-\2	effgz-effgz-
((((((((((a))))))))))	-	c	-	-
(((((((((a)))))))))	a	y	&	a
multiple words of text	uh-uh	n	-	-
multiple words	multiple words, yeah	y	&	multiple words
(.*)c(.*)	abcde	y	&-\1-\2	abcde-ab-de
\((.*), (.*)\)	(a, b)	y	(\2, \1)	(b, a)


================================================
FILE: timer.c
================================================
/*
 * Simple timing program for regcomp().
 * Usage: timer ncomp nexec nsub
 *	or
 *	timer ncomp nexec nsub regexp string [ answer [ sub ] ]
 *
 * The second form is for timing repetitions of a single test case.
 * The first form's test data is a compiled-in copy of the "tests" file.
 * Ncomp, nexec, nsub are how many times to do each regcomp, regexec,
 * and regsub.  The way to time an operation individually is to do something
 * like "timer 1 50 1".
 */
#include <stdio.h>

struct try {
	char *re, *str, *ans, *src, *dst;
} tests[] = {
#include "timer.t.h"
{ NULL, NULL, NULL, NULL, NULL }
};

#include <regexp.h>

int errreport = 0;		/* Report errors via errseen? */
char *errseen = NULL;		/* Error message. */

char *progname;

/* ARGSUSED */
main(argc, argv)
int argc;
char *argv[];
{
	int ncomp, nexec, nsub;
	struct try one;
	char dummy[512];

	if (argc < 4) {
		ncomp = 1;
		nexec = 1;
		nsub = 1;
	} else {
		ncomp = atoi(argv[1]);
		nexec = atoi(argv[2]);
		nsub = atoi(argv[3]);
	}
	
	progname = argv[0];
	if (argc > 5) {
		one.re = argv[4];
		one.str = argv[5];
		if (argc > 6)
			one.ans = argv[6];
		else
			one.ans = "y";
		if (argc > 7) {	
			one.src = argv[7];
			one.dst = "xxx";
		} else {
			one.src = "x";
			one.dst = "x";
		}
		errreport = 1;
		try(one, ncomp, nexec, nsub);
	} else
		multiple(ncomp, nexec, nsub);
	exit(0);
}

void
regerror(s)
char *s;
{
	if (errreport)
		errseen = s;
	else
		error(s, "");
}

#ifndef ERRAVAIL
error(s1, s2)
char *s1;
char *s2;
{
	fprintf(stderr, "regexp: ");
	fprintf(stderr, s1, s2);
	fprintf(stderr, "\n");
	exit(1);
}
#endif

int lineno = 0;

multiple(ncomp, nexec, nsub)
int ncomp, nexec, nsub;
{
	register int i;
	extern char *strchr();

	errreport = 1;
	for (i = 0; tests[i].re != NULL; i++) {
		lineno++;
		try(tests[i], ncomp, nexec, nsub);
	}
}

try(fields, ncomp, nexec, nsub)
struct try fields;
int ncomp, nexec, nsub;
{
	regexp *r;
	char dbuf[BUFSIZ];
	register int i;

	errseen = NULL;
	r = regcomp(fields.re);
	if (r == NULL) {
		if (*fields.ans != 'c')
			complain("regcomp failure in `%s'", fields.re);
		return;
	}
	if (*fields.ans == 'c') {
		complain("unexpected regcomp success in `%s'", fields.re);
		free((char *)r);
		return;
	}
	for (i = ncomp-1; i > 0; i--) {
		free((char *)r);
		r = regcomp(fields.re);
	}
	if (!regexec(r, fields.str)) {
		if (*fields.ans != 'n')
			complain("regexec failure in `%s'", "");
		free((char *)r);
		return;
	}
	if (*fields.ans == 'n') {
		complain("unexpected regexec success", "");
		free((char *)r);
		return;
	}
	for (i = nexec-1; i > 0; i--)
		(void) regexec(r, fields.str);
	errseen = NULL;
	for (i = nsub; i > 0; i--)
		regsub(r, fields.src, dbuf);
	if (errseen != NULL) {	
		complain("regsub complaint", "");
		free((char *)r);
		return;
	}
	if (strcmp(dbuf, fields.dst) != 0)
		complain("regsub result `%s' wrong", dbuf);
	free((char *)r);
}

complain(s1, s2)
char *s1;
char *s2;
{
	fprintf(stderr, "try: %d: ", lineno);
	fprintf(stderr, s1, s2);
	fprintf(stderr, " (%s)\n", (errseen != NULL) ? errseen : "");
}


================================================
FILE: try.c
================================================
/*
 * Simple test program for regexp(3) stuff.  Knows about debugging hooks.
 * Usage: try re [string [output [-]]]
 * The re is compiled and dumped, regexeced against the string, the result
 * is applied to output using regsub().  The - triggers a running narrative
 * from regexec().  Dumping and narrative don't happen unless DEBUG.
 *
 * If there are no arguments, stdin is assumed to be a stream of lines with
 * five fields:  a r.e., a string to match it against, a result code, a
 * source string for regsub, and the proper result.  Result codes are 'c'
 * for compile failure, 'y' for match success, 'n' for match failure.
 * Field separator is tab.
 */
#include <stdio.h>
#include <regexp.h>

#ifdef ERRAVAIL
char *progname;
extern char *mkprogname();
#endif

#ifdef DEBUG
extern int regnarrate;
#endif

char buf[BUFSIZ];

int errreport = 0;		/* Report errors via errseen? */
char *errseen = NULL;		/* Error message. */
int status = 0;			/* Exit status. */

/* ARGSUSED */
main(argc, argv)
int argc;
char *argv[];
{
	regexp *r;
	int i;

#ifdef ERRAVAIL
	progname = mkprogname(argv[0]);
#endif

	if (argc == 1) {
		multiple();
		exit(status);
	}

	r = regcomp(argv[1]);
	if (r == NULL)
		error("regcomp failure", "");
#ifdef DEBUG
	regdump(r);
	if (argc > 4)
		regnarrate++;
#endif
	if (argc > 2) {
		i = regexec(r, argv[2]);
		printf("%d", i);
		for (i = 1; i < NSUBEXP; i++)
			if (r->startp[i] != NULL && r->endp[i] != NULL)
				printf(" \\%d", i);
		printf("\n");
	}
	if (argc > 3) {
		regsub(r, argv[3], buf);
		printf("%s\n", buf);
	}
	exit(status);
}

void
regerror(s)
char *s;
{
	if (errreport)
		errseen = s;
	else
		error(s, "");
}

#ifndef ERRAVAIL
error(s1, s2)
char *s1;
char *s2;
{
	fprintf(stderr, "regexp: ");
	fprintf(stderr, s1, s2);
	fprintf(stderr, "\n");
	exit(1);
}
#endif

int lineno;

regexp badregexp;		/* Implicit init to 0. */

multiple()
{
	char rbuf[BUFSIZ];
	char *field[5];
	char *scan;
	int i;
	regexp *r;
	extern char *strchr();

	errreport = 1;
	lineno = 0;
	while (fgets(rbuf, sizeof(rbuf), stdin) != NULL) {
		rbuf[strlen(rbuf)-1] = '\0';	/* Dispense with \n. */
		lineno++;
		scan = rbuf;
		for (i = 0; i < 5; i++) {
			field[i] = scan;
			if (field[i] == NULL) {
				complain("bad testfile format", "");
				exit(1);
			}
			scan = strchr(scan, '\t');
			if (scan != NULL)
				*scan++ = '\0';
		}
		try(field);
	}

	/* And finish up with some internal testing... */
	lineno = 9990;
	errseen = NULL;
	if (regcomp((char *)NULL) != NULL || errseen == NULL)
		complain("regcomp(NULL) doesn't complain", "");
	lineno = 9991;
	errseen = NULL;
	if (regexec((regexp *)NULL, "foo") || errseen == NULL)
		complain("regexec(NULL, ...) doesn't complain", "");
	lineno = 9992;
	r = regcomp("foo");
	if (r == NULL) {
		complain("regcomp(\"foo\") fails", "");
		return;
	}
	lineno = 9993;
	errseen = NULL;
	if (regexec(r, (char *)NULL) || errseen == NULL)
		complain("regexec(..., NULL) doesn't complain", "");
	lineno = 9994;
	errseen = NULL;
	regsub((regexp *)NULL, "foo", rbuf);
	if (errseen == NULL)
		complain("regsub(NULL, ..., ...) doesn't complain", "");
	lineno = 9995;
	errseen = NULL;
	regsub(r, (char *)NULL, rbuf);
	if (errseen == NULL)
		complain("regsub(..., NULL, ...) doesn't complain", "");
	lineno = 9996;
	errseen = NULL;
	regsub(r, "foo", (char *)NULL);
	if (errseen == NULL)
		complain("regsub(..., ..., NULL) doesn't complain", "");
	lineno = 9997;
	errseen = NULL;
	if (regexec(&badregexp, "foo") || errseen == NULL)
		complain("regexec(nonsense, ...) doesn't complain", "");
	lineno = 9998;
	errseen = NULL;
	regsub(&badregexp, "foo", rbuf);
	if (errseen == NULL)
		complain("regsub(nonsense, ..., ...) doesn't complain", "");
}

try(fields)
char **fields;
{
	regexp *r;
	char dbuf[BUFSIZ];

	errseen = NULL;
	r = regcomp(fields[0]);
	if (r == NULL) {
		if (*fields[2] != 'c')
			complain("regcomp failure in `%s'", fields[0]);
		return;
	}
	if (*fields[2] == 'c') {
		complain("unexpected regcomp success in `%s'", fields[0]);
		free((char *)r);
		return;
	}
	if (!regexec(r, fields[1])) {
		if (*fields[2] != 'n')
			complain("regexec failure in `%s'", fields[0]);
		free((char *)r);
		return;
	}
	if (*fields[2] == 'n') {
		complain("unexpected regexec success", "");
		free((char *)r);
		return;
	}
	errseen = NULL;
	regsub(r, fields[3], dbuf);
	if (errseen != NULL) {
		complain("regsub complaint", "");
		free((char *)r);
		return;
	}
	if (strcmp(dbuf, fields[4]) != 0)
		complain("regsub result `%s' wrong", dbuf);
	free((char *)r);
}

complain(s1, s2)
char *s1;
char *s2;
{
	fprintf(stderr, "try: %d: ", lineno);
	fprintf(stderr, s1, s2);
	fprintf(stderr, " (%s)\n", (errseen != NULL) ? errseen : "");
	status = 1;
}