Home | History | Annotate | Line # | Download | only in ed
re.c revision 1.11 
      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 #endif /* not lint */
     32 
     33 #include <stdio.h>
     34 #include <stdlib.h>
     35 #include <string.h>
     36 
     37 #include "ed.h"
     38 
     39 extern char *lhbuf;
     40 extern int lhbufsz;
     41 extern char *ibufp;
     42 extern int ibufsz;
     43 extern int patlock;
     44 
     45 char errmsg[MAXFNAME + 40] = "";
     46 
     47 /* optpat: return pointer to compiled pattern from command buffer */
     48 pattern_t *
     49 optpat()
     50 {
     51 	static pattern_t *exp = NULL;
     52 
     53 	char *exps;
     54 	char delim;
     55 	int n;
     56 
     57 	if ((delim = *ibufp) == ' ') {
     58 		sprintf(errmsg, "invalid pattern delimiter");
     59 		return NULL;
     60 	} else if (delim == '\n' || *++ibufp == '\n' || *ibufp == delim) {
     61 		if (!exp) sprintf(errmsg, "no previous pattern");
     62 		return exp;
     63 	} else if ((exps = getlhs(delim)) == NULL)
     64 		return NULL;
     65 	/* buffer alloc'd && not reserved */
     66 	if (exp && !patlock)
     67 		regfree(exp);
     68 	else if ((exp = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) {
     69 		fprintf(stderr, "%s\n", strerror(errno));
     70 		sprintf(errmsg, "out of memory");
     71 		return NULL;
     72 	}
     73 	patlock = 0;
     74 	if (n = regcomp(exp, exps, 0)) {
     75 		regerror(n, exp, errmsg, sizeof errmsg);
     76 		free(exp);
     77 		return exp = NULL;
     78 	}
     79 	return exp;
     80 }
     81 
     82 
     83 extern int isbinary;
     84 
     85 /* getlhs: copy a pattern string from the command buffer; return pointer
     86    to the copy */
     87 char *
     88 getlhs(delim)
     89 	int delim;
     90 {
     91 	char *nd;
     92 	int len;
     93 
     94 	for (nd = ibufp; *nd != delim && *nd != '\n'; nd++)
     95 		switch (*nd) {
     96 		default:
     97 			break;
     98 		case '[':
     99 			if ((nd = ccl(++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 	CKBUF(lhbuf, lhbufsz, len + 1, NULL);
    113 	memcpy(lhbuf, ibufp, len);
    114 	lhbuf[len] = '\0';
    115 	ibufp = nd;
    116 	return (isbinary) ? nultonl(lhbuf, len) : lhbuf;
    117 }
    118 
    119 
    120 /* ccl: expand a POSIX character class */
    121 char *
    122 ccl(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