/* c-strstr.c -- substring search in C locale
- Copyright (C) 2005-2007 Free Software Foundation, Inc.
+ Copyright (C) 2005-2011 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2005, 2007.
- This program is free software; you can redistribute it and/or modify
+ 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.
+ the Free Software Foundation; either version 3 of the License, 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
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
#include "c-strstr.h"
-#include <stddef.h>
+#include <string.h>
/* Find the first occurrence of NEEDLE in HAYSTACK. */
char *
c_strstr (const char *haystack, const char *needle)
{
- /* Be careful not to look at the entire extent of haystack or needle
- until needed. This is useful because of these two cases:
- - haystack may be very long, and a match of needle found early,
- - needle may be very long, and not even a short initial segment of
- needle may be found in haystack. */
- if (*needle != '\0')
- {
- /* Speed up the following searches of needle by caching its first
- character. */
- unsigned char b = (unsigned char) *needle;
-
- needle++;
- for (;; haystack++)
- {
- if (*haystack == '\0')
- /* No match. */
- return NULL;
- if ((unsigned char) *haystack == b)
- /* The first character matches. */
- {
- const char *rhaystack = haystack + 1;
- const char *rneedle = needle;
-
- for (;; rhaystack++, rneedle++)
- {
- if (*rneedle == '\0')
- /* Found a match. */
- return (char *) haystack;
- if (*rhaystack == '\0')
- /* No match. */
- return NULL;
- if ((unsigned char) *rhaystack != (unsigned char) *rneedle)
- /* Nothing in this round. */
- break;
- }
- }
- }
- }
- else
- return (char *) haystack;
+ /* POSIX says that strstr() interprets the strings as byte sequences, not
+ as character sequences in the current locale. */
+ return strstr (haystack, needle);
}