/* Determine whether string value is affirmation or negative response
   according to current locale's data.
   Copyright (C) 1996, 1998 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#if HAVE_CONFIG_H
# include <config.h>
#endif

#if STDC_HEADERS || _LIBC
# include <stddef.h>
# include <stdlib.h>
#else
# ifndef NULL
#  define NULL 0
# endif
#endif

#include <sys/types.h>
#include <regex.h>

#if ENABLE_NLS
# include <libintl.h>
# define _(Text) gettext (Text)
#else
# define _(Text) Text
#endif

static int
try (response, pattern, match, nomatch, lastp, re)
     const char *response;
     const char *pattern;
     const int match;
     const int nomatch;
     const char **lastp;
     regex_t *re;
{
  if (pattern != *lastp)
    {
      /* The pattern has changed.  */
      if (*lastp)
	{
	  /* Free the old compiled pattern.  */
	  regfree (re);
	  *lastp = NULL;
	}
      /* Compile the pattern and cache it for future runs.  */
      if (regcomp (re, pattern, REG_EXTENDED) != 0)
	return -1;
      *lastp = pattern;
    }

  /* See if the regular expression matches RESPONSE.  */
  return regexec (re, response, 0, NULL, 0) == 0 ? match : nomatch;
}


int
rpmatch (response)
     const char *response;
{
  /* Match against one of the response patterns, compiling the pattern
     first if necessary.  */

  /* We cache the response patterns and compiled regexps here.  */
  static const char *yesexpr, *noexpr;
  static regex_t yesre, nore;
  int result;

  return ((result = try (response, _("^[yY]"), 1, 0,
			 &yesexpr, &yesre))
	  ? result
	  : try (response, _("^[nN]"), 0, -1, &noexpr, &nore));
}
