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/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 59 Temple Place -
Suite 330, Boston, MA 02111-1307, USA.
This file was modified slightly by Ian Lance Taylor, May 1992, for
Taylor UUCP. */
#include "uucp.h"
/* Return the first ocurrence of NEEDLE in HAYSTACK. */
char *
strstr (haystack, needle)
const char *const haystack;
const char *const needle;
{
register const char *const needle_end = strchr(needle, '\0');
register const char *const haystack_end = strchr(haystack, '\0');
register const size_t needle_len = needle_end - needle;
register const size_t needle_last = needle_len - 1;
register const char *begin;
if (needle_len == 0)
return (char *) haystack_end;
if ((size_t) (haystack_end - haystack) < needle_len)
return NULL;
for (begin = &haystack[needle_last]; begin < haystack_end; ++begin)
{
register const char *n = &needle[needle_last];
register const char *h = begin;
do
if (*h != *n)
goto loop;
while (--n >= needle && --h >= haystack);
return (char *) h;
loop:;
}
return NULL;
}
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