lib/sh/shmatch.c

   1 /*
   2  * shmatch.c -- shell interface to posix regular expression matching.
   3  */
   4
   5 /* Copyright (C) 2003-2015 Free Software Foundation, Inc.
   6
   7    This file is part of GNU Bash, the Bourne Again SHell.
   8
   9    Bash is free software: you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation, either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    Bash is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #  include <config.h>
  25 #endif
  26
  27 #if defined (HAVE_POSIX_REGEXP)
  28
  29 #ifdef HAVE_UNISTD_H
  30 #  include <unistd.h>
  31 #endif
  32
  33 #include "bashansi.h"
  34
  35 #include <stdio.h>
  36 #include <regex.h>
  37
  38 #include "shell.h"
  39 #include "variables.h"
  40 #include "externs.h"
  41
  42 extern int glob_ignore_case, match_ignore_case;
  43
  44 int
  45 sh_regmatch (string, pattern, flags)
  46      const char *string;
  47      const char *pattern;
  48      int flags;
  49 {
  50   regex_t regex = { 0 };
  51   regmatch_t *matches;
  52   int rflags;
  53 #if defined (ARRAY_VARS)
  54   SHELL_VAR *rematch;
  55   ARRAY *amatch;
  56   int subexp_ind;
  57   char *subexp_str;
  58   int subexp_len;
  59 #endif
  60   int result;
  61
  62 #if defined (ARRAY_VARS)
  63   rematch = (SHELL_VAR *)NULL;
  64 #endif
  65
  66   rflags = REG_EXTENDED;
  67   if (glob_ignore_case || match_ignore_case)
  68     rflags |= REG_ICASE;
  69 #if !defined (ARRAY_VARS)
  70   rflags |= REG_NOSUB;
  71 #endif
  72
  73   if (regcomp (&regex, pattern, rflags))
  74     return 2;           /* flag for printing a warning here. */
  75
  76 #if defined (ARRAY_VARS)
  77   matches = (regmatch_t *)malloc (sizeof (regmatch_t) * (regex.re_nsub + 1));
  78 #else
  79   matches = NULL;
  80 #endif
  81
  82   /* man regexec: NULL PMATCH ignored if NMATCH == 0 */
  83   if (regexec (&regex, string, matches ? regex.re_nsub + 1 : 0, matches, 0))
  84     result = EXECUTION_FAILURE;
  85   else
  86     result = EXECUTION_SUCCESS;         /* match */
  87
  88 #if defined (ARRAY_VARS)
  89   subexp_len = strlen (string) + 10;
  90   subexp_str = malloc (subexp_len + 1);
  91
  92   /* Store the parenthesized subexpressions in the array BASH_REMATCH.
  93      Element 0 is the portion that matched the entire regexp.  Element 1
  94      is the part that matched the first subexpression, and so on. */
  95   unbind_variable_noref ("BASH_REMATCH");
  96   rematch = make_new_array_variable ("BASH_REMATCH");
  97   amatch = array_cell (rematch);
  98
  99   if (matches && (flags & SHMAT_SUBEXP) && result == EXECUTION_SUCCESS && subexp_str)
 100     {
 101       for (subexp_ind = 0; subexp_ind <= regex.re_nsub; subexp_ind++)
 102         {
 103           memset (subexp_str, 0, subexp_len);
 104           strncpy (subexp_str, string + matches[subexp_ind].rm_so,
 105                      matches[subexp_ind].rm_eo - matches[subexp_ind].rm_so);
 106           array_insert (amatch, subexp_ind, subexp_str);
 107         }
 108     }
 109
 110   VSETATTR (rematch, att_readonly);
 111
 112   free (subexp_str);
 113   free (matches);
 114 #endif /* ARRAY_VARS */
 115
 116   regfree (&regex);
 117
 118   return result;
 119 }
 120
 121 #endif /* HAVE_POSIX_REGEXP */