mdw@git.distorted.org.uk Git - anag/blob - pcre.c

   1 /* -*-c-*-
   2  *
   3  * Matches Perl-compatible regular expressions
   4  *
   5  * (c) 2002 Mark Wooding
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Anag: a simple wordgame helper.
  11  *
  12  * Anag is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * Anag is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with Anag; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 /*----- Header files ------------------------------------------------------*/
  28
  29 #ifdef HAVE_CONFIG_H
  30 #  include "config.h"
  31 #endif
  32
  33 #ifndef HAVE_PCRE
  34   extern int dummy;
  35 #else
  36
  37 #include "anag.h"
  38 #include <pcre.h>
  39
  40 /*----- Data structures ---------------------------------------------------*/
  41
  42 typedef struct node_pcre {
  43   node n;
  44   const char *s;
  45   pcre *rx;
  46   pcre_extra *rx_study;
  47   int *ovec;
  48   int ovecsz;
  49 } node_pcre;
  50
  51 /*----- Main code ---------------------------------------------------------*/
  52
  53 /* --- Node matcher --- */
  54
  55 static int n_pcre(node *nn, const char *p, size_t sz)
  56 {
  57   node_pcre *n = (node_pcre *)nn;
  58   int e;
  59
  60   e = pcre_exec(n->rx, n->rx_study, p, sz, 0, 0, n->ovec, n->ovecsz);
  61   if (e >= 0)
  62     return (1);
  63   if (e == PCRE_ERROR_NOMATCH)
  64     return (0);
  65   die("unexpected PCRE error code %d", e);
  66   return (-1);
  67 }
  68
  69 /* --- Node creation --- */
  70
  71 node *pcrenode(const char *const *av)
  72 {
  73   node_pcre *n = xmalloc(sizeof(*n));
  74   const char *e;
  75   int eo;
  76   int c;
  77
  78   n->n.func = n_pcre;
  79   if ((n->rx = pcre_compile(av[0], PCRE_CASELESS, &e, &eo, 0)) == 0)
  80     die("bad regular expression `%s': %s", av[0], e);
  81   n->rx_study = pcre_study(n->rx, 0, &e);
  82   if (e)
  83     die("error studying pattern `%s': %s", av[0], e);
  84   pcre_fullinfo(n->rx, n->rx_study, PCRE_INFO_BACKREFMAX, &c);
  85   n->ovecsz = c * 2;
  86   n->ovec = xmalloc(n->ovecsz * sizeof(*n->ovec));
  87   return (&n->n);
  88 }
  89
  90 /*----- That's all, folks -------------------------------------------------*/
  91
  92 #endif