freebsd-dev/bin/ed/re.c
1994-03-23 04:36:59 +00:00

133 lines
3.6 KiB
C

/* re.c: This file contains the regular expression interface routines for
the ed line editor. */
/*-
* Copyright (c) 1993 Andrew Moore, Talke Studio.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#ifndef lint
static char *rcsid = "@(#)re.c,v 1.6 1994/02/01 00:34:43 alm Exp";
#endif /* not lint */
#include "ed.h"
extern int patlock;
char errmsg[MAXPATHLEN + 40] = "";
/* get_compiled_pattern: return pointer to compiled pattern from command
buffer */
pattern_t *
get_compiled_pattern()
{
static pattern_t *exp = NULL;
char *exps;
char delimiter;
int n;
if ((delimiter = *ibufp) == ' ') {
sprintf(errmsg, "invalid pattern delimiter");
return NULL;
} else if (delimiter == '\n' || *++ibufp == '\n' || *ibufp == delimiter) {
if (!exp) sprintf(errmsg, "no previous pattern");
return exp;
} else if ((exps = extract_pattern(delimiter)) == NULL)
return NULL;
/* buffer alloc'd && not reserved */
if (exp && !patlock)
regfree(exp);
else if ((exp = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) {
fprintf(stderr, "%s\n", strerror(errno));
sprintf(errmsg, "out of memory");
return NULL;
}
patlock = 0;
if (n = regcomp(exp, exps, 0)) {
regerror(n, exp, errmsg, sizeof errmsg);
free(exp);
return exp = NULL;
}
return exp;
}
/* extract_pattern: copy a pattern string from the command buffer; return
pointer to the copy */
char *
extract_pattern(delimiter)
int delimiter;
{
static char *lhbuf = NULL; /* buffer */
static int lhbufsz = 0; /* buffer size */
char *nd;
int len;
for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++)
switch (*nd) {
default:
break;
case '[':
if ((nd = parse_char_class(++nd)) == NULL) {
sprintf(errmsg, "unbalanced brackets ([])");
return NULL;
}
break;
case '\\':
if (*++nd == '\n') {
sprintf(errmsg, "trailing backslash (\\)");
return NULL;
}
break;
}
len = nd - ibufp;
REALLOC(lhbuf, lhbufsz, len + 1, NULL);
memcpy(lhbuf, ibufp, len);
lhbuf[len] = '\0';
ibufp = nd;
return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf;
}
/* parse_char_class: expand a POSIX character class */
char *
parse_char_class(s)
char *s;
{
int c, d;
if (*s == '^')
s++;
if (*s == ']')
s++;
for (; *s != ']' && *s != '\n'; s++)
if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '='))
for (s++, c = *++s; *s != ']' || c != d; s++)
if ((c = *s) == '\n')
return NULL;
return (*s == ']') ? s : NULL;
}