bin/ed/re.c

   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  * @(#)re.c,v 1.6 1994/02/01 00:34:43 alm Exp
  29  * $FreeBSD: src/bin/ed/re.c,v 1.15.2.1 2001/08/01 02:36:03 obrien Exp $
  30  * $DragonFly: src/bin/ed/re.c,v 1.3 2003/09/28 14:39:14 hmp Exp $
  31  */
  32
  33 #include "ed.h"
  34
  35
  36 extern int patlock;
  37
  38 char errmsg[PATH_MAX + 40] = "";
  39
  40 /* get_compiled_pattern: return pointer to compiled pattern from command
  41    buffer */
  42 pattern_t *
  43 get_compiled_pattern(void)
  44 {
  45         static pattern_t *exp = NULL;
  46
  47         char *exps;
  48         char delimiter;
  49         int n;
  50
  51         if ((delimiter = *ibufp) == ' ') {
  52                 sprintf(errmsg, "invalid pattern delimiter");
  53                 return NULL;
  54         } else if (delimiter == '\n' || *++ibufp == '\n' || *ibufp == delimiter) {
  55                 if (!exp) sprintf(errmsg, "no previous pattern");
  56                 return exp;
  57         } else if ((exps = extract_pattern(delimiter)) == NULL)
  58                 return NULL;
  59         /* buffer alloc'd && not reserved */
  60         if (exp && !patlock)
  61                 regfree(exp);
  62         else if ((exp = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) {
  63                 fprintf(stderr, "%s\n", strerror(errno));
  64                 sprintf(errmsg, "out of memory");
  65                 return NULL;
  66         }
  67         patlock = 0;
  68         if ((n = regcomp(exp, exps, 0))) {
  69                 regerror(n, exp, errmsg, sizeof errmsg);
  70                 free(exp);
  71                 return exp = NULL;
  72         }
  73         return exp;
  74 }
  75
  76
  77 /* extract_pattern: copy a pattern string from the command buffer; return
  78    pointer to the copy */
  79 char *
  80 extract_pattern(int delimiter)
  81 {
  82         static char *lhbuf = NULL;      /* buffer */
  83         static int lhbufsz = 0;         /* buffer size */
  84
  85         char *nd;
  86         int len;
  87
  88         for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++)
  89                 switch (*nd) {
  90                 default:
  91                         break;
  92                 case '[':
  93                         if ((nd = parse_char_class(++nd)) == NULL) {
  94                                 sprintf(errmsg, "unbalanced brackets ([])");
  95                                 return NULL;
  96                         }
  97                         break;
  98                 case '\\':
  99                         if (*++nd == '\n') {
 100                                 sprintf(errmsg, "trailing backslash (\\)");
 101                                 return NULL;
 102                         }
 103                         break;
 104                 }
 105         len = nd - ibufp;
 106         REALLOC(lhbuf, lhbufsz, len + 1, NULL);
 107         memcpy(lhbuf, ibufp, len);
 108         lhbuf[len] = '\0';
 109         ibufp = nd;
 110         return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf;
 111 }
 112
 113
 114 /* parse_char_class: expand a POSIX character class */
 115 char *
 116 parse_char_class(char *s)
 117 {
 118         int c, d;
 119
 120         if (*s == '^')
 121                 s++;
 122         if (*s == ']')
 123                 s++;
 124         for (; *s != ']' && *s != '\n'; s++)
 125                 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '='))
 126                         for (s++, c = *++s; *s != ']' || c != d; s++)
 127                                 if ((c = *s) == '\n')
 128                                         return NULL;
 129         return  (*s == ']') ? s : NULL;
 130 }