-/* Copyright (C) 1994, 1999, 2002-2003, 2005-2006 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
+/* c-strstr.c -- substring search in C locale
+ Copyright (C) 2005-2010 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
-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 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 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
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+ 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
-
-/*
- * My personal strstr() implementation that beats most other algorithms.
- * Until someone tells me otherwise, I assume that this is the
- * fastest implementation of strstr() in C.
- * I deliberately chose not to comment it. You should have at least
- * as much fun trying to understand it, as I had to write it :-).
- *
- * Stephen R. van den Berg, berg@pool.informatik.rwth-aachen.de */
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
#include <string.h>
-typedef unsigned chartype;
-
+/* Find the first occurrence of NEEDLE in HAYSTACK. */
char *
-c_strstr (const char *phaystack, const char *pneedle)
+c_strstr (const char *haystack, const char *needle)
{
- register const unsigned char *haystack, *needle;
- register chartype b, c;
-
- haystack = (const unsigned char *) phaystack;
- needle = (const unsigned char *) pneedle;
-
- b = *needle;
- if (b != '\0')
- {
- haystack--; /* possible ANSI violation */
- do
- {
- c = *++haystack;
- if (c == '\0')
- goto ret0;
- }
- while (c != b);
-
- c = *++needle;
- if (c == '\0')
- goto foundneedle;
- ++needle;
- goto jin;
-
- for (;;)
- {
- register chartype a;
- register const unsigned char *rhaystack, *rneedle;
-
- do
- {
- a = *++haystack;
- if (a == '\0')
- goto ret0;
- if (a == b)
- break;
- a = *++haystack;
- if (a == '\0')
- goto ret0;
-shloop:; }
- while (a != b);
-
-jin: a = *++haystack;
- if (a == '\0')
- goto ret0;
-
- if (a != c)
- goto shloop;
-
- rhaystack = haystack-- + 1;
- rneedle = needle;
- a = *rneedle;
-
- if (*rhaystack == a)
- do
- {
- if (a == '\0')
- goto foundneedle;
- ++rhaystack;
- a = *++needle;
- if (*rhaystack != a)
- break;
- if (a == '\0')
- goto foundneedle;
- ++rhaystack;
- a = *++needle;
- }
- while (*rhaystack == a);
-
- needle = rneedle; /* took the register-poor approach */
-
- if (a == '\0')
- break;
- }
- }
-foundneedle:
- return (char *) haystack;
-ret0:
- return 0;
+ /* POSIX says that strstr() interprets the strings as byte sequences, not
+ as character sequences in the current locale. */
+ return strstr (haystack, needle);
}