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

   1 /* -*-c-*-
   2  *
   3  * $Id: pcre.c,v 1.2 2004/04/08 01:36:19 mdw Exp $
   4  *
   5  * Matches Perl-compatible regular expressions
   6  *
   7  * (c) 2002 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Anag: a simple wordgame helper.
  13  *
  14  * Anag is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * Anag is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with Anag; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Header files ------------------------------------------------------*/
  30
  31 #ifdef HAVE_CONFIG_H
  32 #  include "config.h"
  33 #endif
  34
  35 #ifndef HAVE_PCRE
  36   extern int dummy;
  37 #else
  38
  39 #include "anag.h"
  40 #include <pcre.h>
  41
  42 /*----- Data structures ---------------------------------------------------*/
  43
  44 typedef struct node_pcre {
  45   node n;
  46   const char *s;
  47   pcre *rx;
  48   pcre_extra *rx_study;
  49   int *ovec;
  50   int ovecsz;
  51 } node_pcre;
  52
  53 /*----- Main code ---------------------------------------------------------*/
  54
  55 /* --- Node matcher --- */
  56
  57 static int n_pcre(node *nn, const char *p, size_t sz)
  58 {
  59   node_pcre *n = (node_pcre *)nn;
  60   int e;
  61
  62   e = pcre_exec(n->rx, n->rx_study, p, sz, 0, 0, n->ovec, n->ovecsz);
  63   if (e >= 0)
  64     return (1);
  65   if (e == PCRE_ERROR_NOMATCH)
  66     return (0);
  67   die("unexpected PCRE error code %d", e);
  68   return (-1);
  69 }
  70
  71 /* --- Node creation --- */
  72
  73 node *pcrenode(const char *const *av)
  74 {
  75   node_pcre *n = xmalloc(sizeof(*n));
  76   const char *e;
  77   int eo;
  78   int c;
  79
  80   n->n.func = n_pcre;
  81   if ((n->rx = pcre_compile(av[0], PCRE_CASELESS, &e, &eo, 0)) == 0)
  82     die("bad regular expression `%s': %s", av[0], e);
  83   n->rx_study = pcre_study(n->rx, 0, &e);
  84   if (e)
  85     die("error studying pattern `%s': %s", av[0], e);
  86   pcre_fullinfo(n->rx, n->rx_study, PCRE_INFO_BACKREFMAX, &c);
  87   n->ovecsz = c * 2;
  88   n->ovec = xmalloc(n->ovecsz * sizeof(*n->ovec));
  89   return (&n->n);
  90 }
  91
  92 /*----- That's all, folks -------------------------------------------------*/
  93
  94 #endif