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re.c revision 1.12 
      1 /* re.c: This file contains the regular expression interface routines for
      2    the ed line editor. */
      3 /*-
      4  * Copyright (c) 1993 Andrew Moore, Talke Studio.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #ifndef lint
     30 /* static char sccsid[] = "@(#)re.c	5.5 (Talke Studio) 3/28/93"; */
     31 static char rcsid[] = "$Id: re.c,v 1.12 1993/11/23 04:41:55 alm Exp $";
     32 #endif /* not lint */
     33 
     34 #include <stdio.h>
     35 #include <stdlib.h>
     36 #include <string.h>
     37 
     38 #include "ed.h"
     39 
     40 extern char *lhbuf;
     41 extern int lhbufsz;
     42 extern char *ibufp;
     43 extern int ibufsz;
     44 extern int patlock;
     45 
     46 char errmsg[MAXFNAME + 40] = "";
     47 
     48 /* get_compiled_pattern: return pointer to compiled pattern from command
     49    buffer */
     50 pattern_t *
     51 get_compiled_pattern()
     52 {
     53 	static pattern_t *exp = NULL;
     54 
     55 	char *exps;
     56 	char delimiter;
     57 	int n;
     58 
     59 	if ((delimiter = *ibufp) == ' ') {
     60 		sprintf(errmsg, "invalid pattern delimiter");
     61 		return NULL;
     62 	} else if (delimiter == '\n' || *++ibufp == '\n' || *ibufp == delimiter) {
     63 		if (!exp) sprintf(errmsg, "no previous pattern");
     64 		return exp;
     65 	} else if ((exps = extract_pattern(delimiter)) == NULL)
     66 		return NULL;
     67 	/* buffer alloc'd && not reserved */
     68 	if (exp && !patlock)
     69 		regfree(exp);
     70 	else if ((exp = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) {
     71 		fprintf(stderr, "%s\n", strerror(errno));
     72 		sprintf(errmsg, "out of memory");
     73 		return NULL;
     74 	}
     75 	patlock = 0;
     76 	if (n = regcomp(exp, exps, 0)) {
     77 		regerror(n, exp, errmsg, sizeof errmsg);
     78 		free(exp);
     79 		return exp = NULL;
     80 	}
     81 	return exp;
     82 }
     83 
     84 
     85 extern int isbinary;
     86 
     87 /* extract_pattern: copy a pattern string from the command buffer; return
     88    pointer to the copy */
     89 char *
     90 extract_pattern(delimiter)
     91 	int delimiter;
     92 {
     93 	char *nd;
     94 	int len;
     95 
     96 	for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++)
     97 		switch (*nd) {
     98 		default:
     99 			break;
    100 		case '[':
    101 			if ((nd = parse_char_class(++nd)) == NULL) {
    102 				sprintf(errmsg, "unbalanced brackets ([])");
    103 				return NULL;
    104 			}
    105 			break;
    106 		case '\\':
    107 			if (*++nd == '\n') {
    108 				sprintf(errmsg, "trailing backslash (\\)");
    109 				return NULL;
    110 			}
    111 			break;
    112 		}
    113 	len = nd - ibufp;
    114 	CKBUF(lhbuf, lhbufsz, len + 1, NULL);
    115 	memcpy(lhbuf, ibufp, len);
    116 	lhbuf[len] = '\0';
    117 	ibufp = nd;
    118 	return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf;
    119 }
    120 
    121 
    122 /* parse_char_class: expand a POSIX character class */
    123 char *
    124 parse_char_class(s)
    125 	char *s;
    126 {
    127 	int c, d;
    128 
    129 	if (*s == '^')
    130 		s++;
    131 	if (*s == ']')
    132 		s++;
    133 	for (; *s != ']' && *s != '\n'; s++)
    134 		if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '='))
    135 			for (s++, c = *++s; *s != ']' || c != d; s++)
    136 				if ((c = *s) == '\n')
    137 					return NULL;
    138 	return  (*s == ']') ? s : NULL;
    139 }
    140