newlib/libc/stdlib/rpmatch.c

   1 /*
   2 FUNCTION
   3 <<rpmatch>>---determine whether response to question is affirmative or negative
   4
   5 INDEX
   6         rpmatch
   7
   8 SYNOPSIS
   9         #include <stdlib.h>
  10         int rpmatch(const char *<[response]>);
  11
  12 DESCRIPTION
  13 The <<rpmatch>> function determines whether <[response]> is an affirmative
  14 or negative response to a question according to the current locale.
  15
  16 RETURNS
  17 <<rpmatch>> returns 1 if <[response]> is affirmative, 0 if negative, or -1
  18 if not recognized as either.
  19
  20 PORTABILITY
  21 <<rpmatch>> is a BSD extension also found in glibc.
  22
  23 NOTES
  24 No supporting OS subroutines are required.
  25 */
  26
  27 /* This code is originally taken from FreeBSD. */
  28 /*-
  29  * Copyright (c) 2004-2005 Tim J. Robbins.
  30  * All rights reserved.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  */
  53
  54 #include <sys/cdefs.h>
  55 #include <sys/types.h>
  56
  57 #include <langinfo.h>
  58 #include <regex.h>
  59 #include <stdlib.h>
  60
  61 int
  62 rpmatch (const char *response)
  63 {
  64         regex_t yes, no;
  65         int ret;
  66
  67         if (regcomp(&yes, nl_langinfo(YESEXPR), REG_EXTENDED|REG_NOSUB) != 0)
  68                 return (-1);
  69         if (regcomp(&no, nl_langinfo(NOEXPR), REG_EXTENDED|REG_NOSUB) != 0) {
  70                 regfree(&yes);
  71                 return (-1);
  72         }
  73         if (regexec(&yes, response, 0, NULL, 0) == 0)
  74                 ret = 1;
  75         else if (regexec(&no, response, 0, NULL, 0) == 0)
  76                 ret = 0;
  77         else
  78                 ret = -1;
  79         regfree(&yes);
  80         regfree(&no);
  81         return (ret);
  82 }