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re.c revision 1.18 
      1 /*	$NetBSD: re.c,v 1.18 2002/12/06 01:39:10 thorpej Exp $	*/
      2 
      3 /* re.c: This file contains the regular expression interface routines for
      4    the ed line editor. */
      5 /*-
      6  * Copyright (c) 1993 Andrew Moore, Talke Studio.
      7  * All rights reserved.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 #include <sys/cdefs.h>
     32 #ifndef lint
     33 #if 0
     34 static char *rcsid = "@(#)re.c,v 1.6 1994/02/01 00:34:43 alm Exp";
     35 #else
     36 __RCSID("$NetBSD: re.c,v 1.18 2002/12/06 01:39:10 thorpej Exp $");
     37 #endif
     38 #endif /* not lint */
     39 
     40 #include "ed.h"
     41 
     42 
     43 char errmsg[MAXPATHLEN + 40] = "";
     44 
     45 /* get_compiled_pattern: return pointer to compiled pattern from command
     46    buffer */
     47 pattern_t *
     48 get_compiled_pattern()
     49 {
     50 	static pattern_t *expr = NULL;
     51 
     52 	char *exps;
     53 	char delimiter;
     54 	int n;
     55 
     56 	if ((delimiter = *ibufp) == ' ') {
     57 		sprintf(errmsg, "invalid pattern delimiter");
     58 		return NULL;
     59 	} else if (delimiter == '\n' || *++ibufp == '\n' || *ibufp == delimiter) {
     60 		if (!expr) sprintf(errmsg, "no previous pattern");
     61 		return expr;
     62 	} else if ((exps = extract_pattern(delimiter)) == NULL)
     63 		return NULL;
     64 	/* buffer alloc'd && not reserved */
     65 	if (expr && !patlock)
     66 		regfree(expr);
     67 	else if ((expr = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) {
     68 		fprintf(stderr, "%s\n", strerror(errno));
     69 		sprintf(errmsg, "out of memory");
     70 		return NULL;
     71 	}
     72 	patlock = 0;
     73 	if ((n = regcomp(expr, exps, ere)) != 0) {
     74 		regerror(n, expr, errmsg, sizeof errmsg);
     75 		free(expr);
     76 		return expr = NULL;
     77 	}
     78 	return expr;
     79 }
     80 
     81 
     82 /* extract_pattern: copy a pattern string from the command buffer; return
     83    pointer to the copy */
     84 char *
     85 extract_pattern(delimiter)
     86 	int delimiter;
     87 {
     88 	static char *lhbuf = NULL;	/* buffer */
     89 	static int lhbufsz = 0;		/* buffer size */
     90 
     91 	char *nd;
     92 	int len;
     93 
     94 	for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++)
     95 		switch (*nd) {
     96 		default:
     97 			break;
     98 		case '[':
     99 			if ((nd = parse_char_class(++nd)) == NULL) {
    100 				sprintf(errmsg, "unbalanced brackets ([])");
    101 				return NULL;
    102 			}
    103 			break;
    104 		case '\\':
    105 			if (*++nd == '\n') {
    106 				sprintf(errmsg, "trailing backslash (\\)");
    107 				return NULL;
    108 			}
    109 			break;
    110 		}
    111 	len = nd - ibufp;
    112 	REALLOC(lhbuf, lhbufsz, len + 1, NULL);
    113 	memcpy(lhbuf, ibufp, len);
    114 	lhbuf[len] = '\0';
    115 	ibufp = nd;
    116 	return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf;
    117 }
    118 
    119 
    120 /* parse_char_class: expand a POSIX character class */
    121 char *
    122 parse_char_class(s)
    123 	char *s;
    124 {
    125 	int c, d;
    126 
    127 	if (*s == '^')
    128 		s++;
    129 	if (*s == ']')
    130 		s++;
    131 	for (; *s != ']' && *s != '\n'; s++)
    132 		if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '='))
    133 			for (s++, c = *++s; *s != ']' || c != d; s++)
    134 				if ((c = *s) == '\n')
    135 					return NULL;
    136 	return  (*s == ']') ? s : NULL;
    137 }
    138