bin/ed/re.c

   1 /*      $NetBSD: re.c,v 1.21 2014/03/23 05:06:42 dholland 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 1.21 2014/03/23 05:06:42 dholland Exp $");
  37 #endif
  38 #endif /* not lint */
  39
  40 #include <stdarg.h>
  41 #include "ed.h"
  42
  43
  44 char errmsg[MAXPATHLEN + 40] = "";
  45
  46 void
  47 seterrmsg(const char *fmt, ...)
  48 {
  49         va_list ap;
  50
  51         va_start(ap, fmt);
  52         vsnprintf(errmsg, sizeof(errmsg), fmt, ap);
  53         va_end(ap);
  54 }
  55
  56 /* get_compiled_pattern: return pointer to compiled pattern from command
  57    buffer */
  58 pattern_t *
  59 get_compiled_pattern(void)
  60 {
  61         static pattern_t *expr = NULL;
  62
  63         char *exps;
  64         char delimiter;
  65         int n;
  66
  67         if ((delimiter = *ibufp) == ' ') {
  68                 seterrmsg("invalid pattern delimiter");
  69                 return NULL;
  70         } else if (delimiter == '\n' || *++ibufp == '\n' || *ibufp == delimiter) {
  71                 if (!expr) seterrmsg("no previous pattern");
  72                 return expr;
  73         } else if ((exps = extract_pattern(delimiter)) == NULL)
  74                 return NULL;
  75         /* buffer alloc'd && not reserved */
  76         if (expr && !patlock)
  77                 regfree(expr);
  78         else if ((expr = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) {
  79                 fprintf(stderr, "%s\n", strerror(errno));
  80                 seterrmsg("out of memory");
  81                 return NULL;
  82         }
  83         patlock = 0;
  84         if ((n = regcomp(expr, exps, ere)) != 0) {
  85                 regerror(n, expr, errmsg, sizeof errmsg);
  86                 free(expr);
  87                 return expr = NULL;
  88         }
  89         return expr;
  90 }
  91
  92
  93 /* extract_pattern: copy a pattern string from the command buffer; return
  94    pointer to the copy */
  95 char *
  96 extract_pattern(int delimiter)
  97 {
  98         static char *lhbuf = NULL;      /* buffer */
  99         static int lhbufsz = 0;         /* buffer size */
 100
 101         char *nd;
 102         int len;
 103
 104         for (nd = ibufp; *nd != delimiter && *nd != '\n'; nd++)
 105                 switch (*nd) {
 106                 default:
 107                         break;
 108                 case '[':
 109                         if ((nd = parse_char_class(nd + 1)) == NULL) {
 110                                 seterrmsg("unbalanced brackets ([])");
 111                                 return NULL;
 112                         }
 113                         break;
 114                 case '\\':
 115                         if (*++nd == '\n') {
 116                                 seterrmsg("trailing backslash (\\)");
 117                                 return NULL;
 118                         }
 119                         break;
 120                 }
 121         len = nd - ibufp;
 122         REALLOC(lhbuf, lhbufsz, len + 1, NULL);
 123         memcpy(lhbuf, ibufp, len);
 124         lhbuf[len] = '\0';
 125         ibufp = nd;
 126         return (isbinary) ? NUL_TO_NEWLINE(lhbuf, len) : lhbuf;
 127 }
 128
 129
 130 /* parse_char_class: expand a POSIX character class */
 131 char *
 132 parse_char_class(char *s)
 133 {
 134         int c, d;
 135
 136         if (*s == '^')
 137                 s++;
 138         if (*s == ']')
 139                 s++;
 140         for (; *s != ']' && *s != '\n'; s++)
 141                 if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '='))
 142                         for (s++, c = *++s; *s != ']' || c != d; s++)
 143                                 if ((c = *s) == '\n')
 144                                         return NULL;
 145         return  (*s == ']') ? s : NULL;
 146 }