bin/ed/re.c

   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(void)
  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(int delimiter)
  86 {
  87         static char *lhbuf = NULL;      /* buffer */
  88         static int lhbufsz = 0;         /* buffer size */
  89
  90         char *nd;
  91         int len;
  92
  93         for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++)
  94                 switch (*nd) {
  95                 default:
  96                         break;
  97                 case '[':
  98                         if ((nd = parse_char_class(++nd)) == NULL) {
  99                                 sprintf(errmsg, "unbalanced brackets ([])");
 100                                 return NULL;
 101                         }
 102                         break;
 103                 case '\\':
 104                         if (*++nd == '\n') {
 105                                 sprintf(errmsg, "trailing backslash (\\)");
 106                                 return NULL;
 107                         }
 108                         break;
 109                 }
 110         len = nd - ibufp;
 111         REALLOC(lhbuf, lhbufsz, len + 1, NULL);
 112         memcpy(lhbuf, ibufp, len);
 113         lhbuf[len] = '\0';
 114         ibufp = nd;
 115         return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf;
 116 }
 117
 118
 119 /* parse_char_class: expand a POSIX character class */
 120 char *
 121 parse_char_class(char *s)
 122 {
 123         int c, d;
 124
 125         if (*s == '^')
 126                 s++;
 127         if (*s == ']')
 128                 s++;
 129         for (; *s != ']' && *s != '\n'; s++)
 130                 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '='))
 131                         for (s++, c = *++s; *s != ']' || c != d; s++)
 132                                 if ((c = *s) == '\n')
 133                                         return NULL;
 134         return  (*s == ']') ? s : NULL;
 135 }