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re.c revision 1.1 
      1 /* re.c: This file contains the regular expression interface routines for
      2    the ed line editor. */
      3 /*-
      4  * Copyright (c) 1993 The Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley
      8  * by Andrew Moore, Talke Studio.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #ifndef lint
     40 static char sccsid[] = "@(#)re.c	5.5 (Berkeley) 3/28/93";
     41 #endif /* not lint */
     42 
     43 #include <stdio.h>
     44 #include <stdlib.h>
     45 #include <string.h>
     46 
     47 #include "ed.h"
     48 
     49 extern char *ibufp;
     50 extern int patlock;
     51 
     52 char errmsg[MAXFNAME + 40] = "";
     53 
     54 /* optpat: return pointer to compiled pattern from command buffer */
     55 pattern_t *
     56 optpat()
     57 {
     58 	static pattern_t *exp = NULL;
     59 
     60 	char *exps;
     61 	char delim;
     62 	int n;
     63 
     64 	if ((delim = *ibufp) == '\n')
     65 		return exp;
     66 	else if (delim == ' ' || *++ibufp == '\n') {
     67 		sprintf(errmsg, "invalid pattern delimiter");
     68 		return NULL;
     69 	} else if (*ibufp == delim)
     70 		return exp;
     71 	else if ((exps = getlhs(delim)) == NULL)
     72 		return NULL;
     73 	/* buffer alloc'd && not reserved */
     74 	if (exp && !patlock)
     75 		regfree(exp);
     76 	else if ((exp = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) {
     77 		fprintf(stderr, "out of memory\n");
     78 		return NULL;
     79 	}
     80 	patlock = 0;
     81 #ifdef GNU_REGEX
     82 	/* initialize pattern buffer */
     83 	exp->buffer = NULL;
     84 	exp->allocated = 0L;
     85 	exp->fastmap = (char *) malloc(FASTMAP_SIZE);
     86 	exp->translate = 0;
     87 #endif
     88 	if (n = regcomp(exp, exps, 0)) {
     89 		regerror(n, exp, errmsg, sizeof errmsg);
     90 		return NULL;
     91 	}
     92 	return exp;
     93 }
     94 
     95 
     96 /* getlhs: copy a pattern string from the command buffer; return pointer
     97    to the copy */
     98 char *
     99 getlhs(delim)
    100 	int delim;
    101 {
    102 	static char buf[MAXLINE];
    103 	char *nd;
    104 
    105 	for (nd = ibufp; *nd != delim && *nd != '\n'; nd++)
    106 		switch (*nd) {
    107 		default:
    108 			break;
    109 		case CCL:
    110 			if ((nd = ccl(CCLEND, ++nd)) == NULL) {
    111 				sprintf(errmsg, "unbalanced brackets ([])");
    112 				return NULL;
    113 			}
    114 			break;
    115 		case ESCHAR:
    116 			if (*++nd == '\n') {
    117 				sprintf(errmsg, "trailing backslash (\\)");
    118 				return NULL;
    119 			}
    120 			break;
    121 		}
    122 	strncpy(buf, ibufp, nd - ibufp);
    123 	buf[nd - ibufp] = '\0';
    124 	ibufp = nd;
    125 	return buf;
    126 }
    127 
    128 
    129 /* ccl: expand a character class */
    130 char *
    131 ccl(delim, src)
    132 	int	delim;
    133 	char	*src;
    134 {
    135 	if (*src == '^')
    136 		src++;
    137 	if (*src == delim)
    138 		src++;
    139 	while (*src != delim && *src != '\n')
    140 		src++;
    141 	return  (*src == delim) ? src : NULL;
    142 }
    143