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exp_regexp.c
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exp_regexp.c
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#if 0 /*WHOLE FILE*/
/*
* regcomp and regexec -- regsub and regerror are elsewhere
*
* Copyright (c) 1986 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 freely,
* 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 as being the original software.
*
* Beware that some of this code is subtly aware of the way operator
* precedence is structured in regular expressions. Serious changes in
* regular-expression syntax might require a total rethink.
*
* *** NOTE: this code has been altered slightly for use in Tcl. ***
* *** The only change is to use ckalloc and ckfree instead of ***
* *** malloc and free. ***
* *** and again for Expect!!! - DEL
* *** More minor corrections stolen from tcl7.5p1/regexp.c - DEL
*/
#include "tcl.h"
#include "expect_cf.h"
#include "exp_prog.h"
#include "tclRegexp.h"
#include "exp_regexp.h"
#include "string.h"
#define NOTSTATIC /* was at one time, but Expect needs access */
/*
* 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 "" at beginning of line. */
#define EOL 2 /* no Match "" at end of line. */
#define ANY 3 /* no Match any one character. */
#define ANYOF 4 /* str Match any character in this string. */
#define ANYBUT 5 /* str Match any character not in this string. */
#define BRANCH 6 /* node Match this alternative, or the next... */
#define BACK 7 /* no Match "", "next" ptr points backward. */
#define EXACTLY 8 /* str Match this string. */
#define NOTHING 9 /* no Match empty string. */
#define STAR 10 /* node Match this (simple) thing 0 or more times. */
#define PLUS 11 /* node Match this (simple) thing 1 or more times. */
#define OPEN 20 /* no Mark this point in input as start of #n. */
/* OPEN+1 is number 1, etc. */
#define CLOSE (OPEN+NSUBEXP) /* 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)&0377)<<8) + (*((p)+2)&0377))
#define OPERAND(p) ((p) + 3)
/*
* See regmagic.h for one further detail of program structure.
*/
/*
* Utility definitions.
*/
#ifndef CHARBITS
#define UCHARAT(p) ((int)*(unsigned char *)(p))
#else
#define UCHARAT(p) ((int)*(p)&CHARBITS)
#endif
#define FAIL(m) { regerror(m); return(NULL); }
#define ISMULT(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. */
/*
* Global work variables for regcomp().
*/
static char *regparse; /* Input-scan pointer. */
static int regnpar; /* () count. */
static char regdummy;
static char *regcode; /* Code-emit pointer; ®dummy = don't. */
static long regsize; /* Code size. */
/*
* The first byte of the regexp internal "program" is actually this magic
* number; the start node begins in the second byte.
*/
#define MAGIC 0234
/*
* Forward declarations for regcomp()'s friends.
*/
#ifndef STATIC
#define STATIC static
#endif
STATIC char *reg();
STATIC char *regbranch();
STATIC char *regpiece();
STATIC char *regatom();
STATIC char *regnode();
STATIC char *regnext();
STATIC void regc();
STATIC void reginsert();
STATIC void regtail();
STATIC void regoptail();
#ifdef STRCSPN
STATIC int strcspn();
#endif
/* regcomp originally appeared here - DEL */
/*
- 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(paren, flagp)
int paren; /* Parenthesized? */
int *flagp;
{
register char *ret;
register char *br;
register char *ender;
register int parno = 0;
int flags;
*flagp = HASWIDTH; /* Tentatively. */
/* Make an OPEN node, if parenthesized. */
if (paren) {
if (regnpar >= NSUBEXP)
FAIL("too many ()");
parno = regnpar;
regnpar++;
ret = regnode(OPEN+parno);
} else
ret = NULL;
/* Pick up the branches, linking them together. */
br = regbranch(&flags);
if (br == NULL)
return(NULL);
if (ret != NULL)
regtail(ret, br); /* OPEN -> first. */
else
ret = br;
if (!(flags&HASWIDTH))
*flagp &= ~HASWIDTH;
*flagp |= flags&SPSTART;
while (*regparse == '|') {
regparse++;
br = regbranch(&flags);
if (br == NULL)
return(NULL);
regtail(ret, br); /* BRANCH -> BRANCH. */
if (!(flags&HASWIDTH))
*flagp &= ~HASWIDTH;
*flagp |= flags&SPSTART;
}
/* Make a closing node, and hook it on the end. */
ender = regnode((paren) ? CLOSE+parno : END);
regtail(ret, ender);
/* Hook the tails of the branches to the closing node. */
for (br = ret; br != NULL; br = regnext(br))
regoptail(br, ender);
/* Check for proper termination. */
if (paren && *regparse++ != ')') {
FAIL("unmatched ()");
} else if (!paren && *regparse != '\0') {
if (*regparse == ')') {
FAIL("unmatched ()");
} else
FAIL("junk on end"); /* "Can't happen". */
/* NOTREACHED */
}
return(ret);
}
/*
- regbranch - one alternative of an | operator
*
* Implements the concatenation operator.
*/
static char *
regbranch(flagp)
int *flagp;
{
register char *ret;
register char *chain;
register char *latest;
int flags;
*flagp = WORST; /* Tentatively. */
ret = regnode(BRANCH);
chain = NULL;
while (*regparse != '\0' && *regparse != '|' && *regparse != ')') {
latest = regpiece(&flags);
if (latest == NULL)
return(NULL);
*flagp |= flags&HASWIDTH;
if (chain == NULL) /* First piece. */
*flagp |= flags&SPSTART;
else
regtail(chain, latest);
chain = latest;
}
if (chain == NULL) /* Loop ran zero times. */
(void) regnode(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(flagp)
int *flagp;
{
register char *ret;
register char op;
register char *next;
int flags;
ret = regatom(&flags);
if (ret == NULL)
return(NULL);
op = *regparse;
if (!ISMULT(op)) {
*flagp = flags;
return(ret);
}
if (!(flags&HASWIDTH) && op != '?')
FAIL("*+ operand could be empty");
*flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH);
if (op == '*' && (flags&SIMPLE))
reginsert(STAR, ret);
else if (op == '*') {
/* Emit x* as (x&|), where & means "self". */
reginsert(BRANCH, ret); /* Either x */
regoptail(ret, regnode(BACK)); /* and loop */
regoptail(ret, ret); /* back */
regtail(ret, regnode(BRANCH)); /* or */
regtail(ret, regnode(NOTHING)); /* null. */
} else if (op == '+' && (flags&SIMPLE))
reginsert(PLUS, ret);
else if (op == '+') {
/* Emit x+ as x(&|), where & means "self". */
next = regnode(BRANCH); /* Either */
regtail(ret, next);
regtail(regnode(BACK), ret); /* loop back */
regtail(next, regnode(BRANCH)); /* or */
regtail(ret, regnode(NOTHING)); /* null. */
} else if (op == '?') {
/* Emit x? as (x|) */
reginsert(BRANCH, ret); /* Either x */
regtail(ret, regnode(BRANCH)); /* or */
next = regnode(NOTHING); /* null. */
regtail(ret, next);
regoptail(ret, next);
}
regparse++;
if (ISMULT(*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(flagp)
int *flagp;
{
register char *ret;
int flags;
*flagp = WORST; /* Tentatively. */
switch (*regparse++) {
case '^':
ret = regnode(BOL);
break;
case '$':
ret = regnode(EOL);
break;
case '.':
ret = regnode(ANY);
*flagp |= HASWIDTH|SIMPLE;
break;
case '[': {
register int clss;
register int classend;
if (*regparse == '^') { /* Complement of range. */
ret = regnode(ANYBUT);
regparse++;
} else
ret = regnode(ANYOF);
if (*regparse == ']' || *regparse == '-')
regc(*regparse++);
while (*regparse != '\0' && *regparse != ']') {
if (*regparse == '-') {
regparse++;
if (*regparse == ']' || *regparse == '\0')
regc('-');
else {
clss = UCHARAT(regparse-2)+1;
classend = UCHARAT(regparse);
if (clss > classend+1)
FAIL("invalid [] range");
for (; clss <= classend; clss++)
regc((char)clss);
regparse++;
}
} else
regc(*regparse++);
}
regc('\0');
if (*regparse != ']')
FAIL("unmatched []");
regparse++;
*flagp |= HASWIDTH|SIMPLE;
}
break;
case '(':
ret = reg(1, &flags);
if (ret == NULL)
return(NULL);
*flagp |= flags&(HASWIDTH|SPSTART);
break;
case '\0':
case '|':
case ')':
FAIL("internal urp"); /* Supposed to be caught earlier. */
/* NOTREACHED */
break;
case '?':
case '+':
case '*':
FAIL("?+* follows nothing");
/* NOTREACHED */
break;
case '\\':
if (*regparse == '\0')
FAIL("trailing \\");
ret = regnode(EXACTLY);
regc(*regparse++);
regc('\0');
*flagp |= HASWIDTH|SIMPLE;
break;
default: {
register int len;
register char ender;
regparse--;
len = strcspn(regparse, META);
if (len <= 0)
FAIL("internal disaster");
ender = *(regparse+len);
if (len > 1 && ISMULT(ender))
len--; /* Back off clear of ?+* operand. */
*flagp |= HASWIDTH;
if (len == 1)
*flagp |= SIMPLE;
ret = regnode(EXACTLY);
while (len > 0) {
regc(*regparse++);
len--;
}
regc('\0');
}
break;
}
return(ret);
}
/*
- regnode - emit a node
*/
static char * /* Location. */
regnode(op)
int op;
{
register char *ret;
register char *ptr;
ret = regcode;
if (ret == ®dummy) {
regsize += 3;
return(ret);
}
ptr = ret;
*ptr++ = (char)op;
*ptr++ = '\0'; /* Null "next" pointer. */
*ptr++ = '\0';
regcode = ptr;
return(ret);
}
/*
- regc - emit (if appropriate) a byte of code
*/
static void
regc(b)
int b;
{
if (regcode != ®dummy)
*regcode++ = (char)b;
else
regsize++;
}
/*
- reginsert - insert an operator in front of already-emitted operand
*
* Means relocating the operand.
*/
static void
reginsert(op, opnd)
int op;
char *opnd;
{
register char *src;
register char *dst;
register char *place;
if (regcode == ®dummy) {
regsize += 3;
return;
}
src = regcode;
regcode += 3;
dst = regcode;
while (src > opnd)
*--dst = *--src;
place = opnd; /* Op node, where operand used to be. */
*place++ = (char)op;
*place++ = '\0';
*place = '\0';
}
/*
- regtail - set the next-pointer at the end of a node chain
*/
static void
regtail(p, val)
char *p;
char *val;
{
register char *scan;
register char *temp;
register int offset;
if (p == ®dummy)
return;
/* Find last node. */
scan = p;
for (;;) {
temp = regnext(scan);
if (temp == NULL)
break;
scan = temp;
}
if (OP(scan) == BACK)
offset = scan - val;
else
offset = val - scan;
*(scan+1) = (char)(offset>>8)&0377;
*(scan+2) = (char)offset&0377;
}
/*
- regoptail - regtail on operand of first argument; nop if operandless
*/
static void
regoptail(p, val)
char *p;
char *val;
{
/* "Operandless" and "op != BRANCH" are synonymous in practice. */
if (p == NULL || p == ®dummy || OP(p) != BRANCH)
return;
regtail(OPERAND(p), val);
}
/*
* regexec and friends
*/
/*
* Global work variables for regexec().
*/
static char *reginput; /* String-input pointer. */
NOTSTATIC char *regbol; /* Beginning of input, for ^ check. */
static char **regstartp; /* Pointer to startp array. */
static char **regendp; /* Ditto for endp. */
/*
* Forwards.
*/
NOTSTATIC int regtry();
STATIC int regmatch();
STATIC int regrepeat();
#ifdef DEBUG
int regnarrate = 0;
void regdump();
STATIC char *regprop();
#endif
#if 0
/*
- regexec - match a regexp against a string
*/
int
regexec(prog, string, stringlength, matchlength)
register regexp *prog;
register char *string; /* note: CURRENTLY ASSUMED TO BE NULL-TERMINATED!!! */
int stringlength; /* length of string */
int *matchlength; /* number of chars matched (or to be skipped) */
/* set when MATCH or CANT_MATCH */
{
register char *s;
extern char *strchr();
/* Be paranoid... */
if (prog == NULL || string == NULL) {
regerror("NULL parameter");
return(EXP_TCLERROR);
}
/* Check validity of program. */
if (UCHARAT(prog->program) != MAGIC) {
regerror("corrupted program");
return(EXP_KM_ERROR);
}
#if THIS_RUINS_EXP
/* no need for this shortcut anyway */
/* If there is a "must appear" string, look for it. */
if (prog->regmust != NULL) {
s = string;
while ((s = strchr(s, prog->regmust[0])) != NULL) {
if (strncmp(s, prog->regmust, prog->regmlen) == 0)
break; /* Found it. */
s++;
}
if (s == NULL) /* Not present. */
return(0);
}
#endif
/* Mark beginning of line for ^ . */
regbol = string;
/* Simplest case: anchored match need be tried only once. */
if (prog->reganch) {
int r = regtry(prog,string,matchlength);
if (r == CANT_MATCH) *matchlength = stringlength;
return(r);
}
/* Messy cases: unanchored match. */
s = string;
if (prog->regstart != '\0') {
register char *s2 = s;
/* We know what char it must start with. */
while (1) {
int r;
s2 = strchr(s2,prog->regstart);
if (s2 == 0) {
*matchlength = stringlength;
return(CANT_MATCH);
}
r = regtry(prog,s2,matchlength);
if (r == CANT_MATCH) {
s2++;
continue;
}
if (s2 == s) return(r);
*matchlength = s2-s;
return CANT_MATCH;
}
} else {
/* We don't -- general case. */
register char *s2 = s;
int r = regtry(prog,s,matchlength);
if (r == EXP_MATCH) return(r);
else if (r == EXP_CANMATCH) return(r);
/* at this point, we know some characters at front */
/* of string don't match */
for (s2++;*s2;s2++) {
r = regtry(prog,s2,matchlength);
if (r == CANT_MATCH) continue;
/* if we match or can_match, say cant_match and */
/* record the number of chars at front that don't match */
*matchlength = s2-s;
return(CANT_MATCH);
}
/* made it thru string with CANT_MATCH all the way */
*matchlength = stringlength;
return(CANT_MATCH);
}
}
#endif
/*
- regtry - try match at specific point
*/
/* return CAN_MATCH, CANT_MATCH or MATCH */
int /* 0 failure, 1 success */
regtry(prog, string, matchlength)
regexp *prog;
char *string;
int *matchlength; /* only set for MATCH */
{
register int i;
register char **sp;
register char **ep;
int r; /* result of regmatch */
reginput = string;
regstartp = prog->startp;
regendp = prog->endp;
sp = prog->startp;
ep = prog->endp;
for (i = NSUBEXP; i > 0; i--) {
*sp++ = NULL;
*ep++ = NULL;
}
r = regmatch(prog->program + 1);
if (EXP_MATCH == r) {
prog->startp[0] = string;
prog->endp[0] = reginput;
*matchlength = reginput-string;
return(EXP_MATCH);
}
return(r); /* CAN_MATCH or CANT_MATCH */
}
/*
- 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.
*/
/* returns CAN, CANT or MATCH */
static int /* 0 failure, 1 success */
regmatch(prog)
char *prog;
{
register char *scan; /* Current node. */
char *next; /* Next node. */
#ifndef strchr /* May be #defined to something else */
extern char *strchr();
#endif
scan = prog;
#ifdef DEBUG
if (scan != NULL && regnarrate)
fprintf(stderr, "%s(\n", regprop(scan));
#endif
while (scan != NULL) {
#ifdef DEBUG
if (regnarrate)
fprintf(stderr, "%s...\n", regprop(scan));
#endif
next = regnext(scan);
switch (OP(scan)) {
case BOL:
if (reginput != regbol)
/* return(0);*/
return(EXP_CANTMATCH);
break;
case EOL:
if (*reginput != '\0')
/* return(0);*/
/* note this implies that "$" must match everything received to this point! */
return(EXP_CANTMATCH);
break;
case ANY:
if (*reginput == '\0')
/* return(0);*/
return(EXP_CANMATCH);
reginput++;
break;
case EXACTLY: {
/* register int len;*/
register char *opnd;
opnd = OPERAND(scan);
/* this section of code is totally rewritten - DEL */
/* group of literal chars in pattern */
/* compare each one */
do {
if (*opnd != *reginput) {
if (*reginput == '\0') {
return EXP_CANMATCH;
} else return EXP_CANTMATCH;
}
reginput++;
opnd++;
} while (*opnd != '\0');
}
break;
case ANYOF:
/* if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) == NULL)
return(0);
*/
if (*reginput == '\0')
return(EXP_CANMATCH);
if (strchr(OPERAND(scan),*reginput) == NULL)
return(EXP_CANTMATCH);
reginput++;
break;
case ANYBUT:
/* if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) != NULL)
return(0);
*/
if (*reginput == '\0')
return(EXP_CANMATCH);
if (strchr(OPERAND(scan),*reginput) != NULL)
return(EXP_CANTMATCH);
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 int no;
register char *save;
int r; /* result of regmatch */
doOpen:
no = OP(scan) - OPEN;
save = reginput;
r = regmatch(next);
if (r == EXP_MATCH) {
/*
* Don't set startp if some later
* invocation of the same parentheses
* already has.
*/
if (regstartp[no] == NULL)
regstartp[no] = save;
}
return(r);
}
/* NOTREACHED */
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 int no;
register char *save;
int r; /* result of regmatch */
doClose:
no = OP(scan) - CLOSE;
save = reginput;
r = regmatch(next);
if (r == EXP_MATCH) {
/*
* Don't set endp if some later
* invocation of the same parentheses
* already has.
*/
if (regendp[no] == NULL)
regendp[no] = save;
}
return(r);
}
/* NOTREACHED */
break;
case BRANCH: {
register char *save;
int match_status;
if (OP(next) != BRANCH) /* No choice. */
next = OPERAND(scan); /* Avoid recursion. */
else {
match_status = EXP_CANTMATCH;
do {
int r;
save = reginput;
r = regmatch(OPERAND(scan));
if (r == EXP_MATCH) return(r);
if (r == EXP_CANMATCH) {
match_status = r;
}
reginput = save;
scan = regnext(scan);
} while (scan != NULL && OP(scan) == BRANCH);
return(match_status);
/* NOTREACHED */
}
}
/* NOTREACHED */
break;
case STAR:
case PLUS: {
register char nextch;
register int no;
register char *save;
register int min;
int match_status;
if (*reginput == '\0') return EXP_CANMATCH;
/*
* Lookahead to avoid useless match attempts
* when we know what character comes next.
*/
match_status = EXP_CANTMATCH;
nextch = '\0';
if (OP(next) == EXACTLY)
nextch = *OPERAND(next);
min = (OP(scan) == STAR) ? 0 : 1;
save = reginput;
no = regrepeat(OPERAND(scan));
while (no >= min) {
/* If it could work, try it. */
/* 3rd condition allows for CAN_MATCH */
if (nextch == '\0' || *reginput == nextch || *reginput == '\0') {
int r = regmatch(next);
if (r == EXP_MATCH)
return(EXP_MATCH);
if (r == EXP_CANMATCH)
/* match_status = r;*/
return(EXP_CANMATCH);
}
/* Couldn't or didn't -- back up. */
no--;
reginput = save + no;
}
return(match_status);
}
/* NOTREACHED */
break;
case END:
/* Success! */
if (*reginput == '\0') {
return(EXP_CANMATCH);
} else {
return(EXP_MATCH);
}
/* return(EXP_CANMATCH); Success! */
/* NOTREACHED */
break;
default: