glibc/stdlib/rpmatch.c

64 lines
2.0 KiB
C

/* Determine whether string value is affirmation or negative response
according to current locale's data.
This file is part of the GNU C Library.
Copyright (C) 1996-2014 Free Software Foundation, Inc.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <langinfo.h>
#include <stdlib.h>
#include <regex.h>
int
rpmatch (response)
const char *response;
{
/* Match against one of the response patterns, compiling the pattern
first if necessary. */
auto int try (const int tag, const int match, const int nomatch,
const char **lastp, regex_t *re);
int try (const int tag, const int match, const int nomatch,
const char **lastp, regex_t *re)
{
const char *pattern = nl_langinfo (tag);
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;
}
/* Try the pattern. */
return __regexec (re, response, 0, NULL, 0) == 0 ? match : nomatch;
}
/* We cache the response patterns and compiled regexps here. */
static const char *yesexpr, *noexpr;
static regex_t yesre, nore;
return (try (YESEXPR, 1, 0, &yesexpr, &yesre) ?:
try (NOEXPR, 0, -1, &noexpr, &nore));
}