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/* Copyright (C) 1991, 1992, 1993, 1994, 1996 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., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <stddef.h>
#include <string.h>
/* Return the first occurrence of NEEDLE in HAYSTACK. */
PTR
DEFUN(memmem, (haystack, haystack_len,
needle, needle_len),
CONST PTRCONST haystack AND CONST size_t haystack_len AND
CONST PTRCONST needle AND CONST size_t needle_len)
{
register CONST char *begin;
register CONST char *CONST last_possible
= (CONST char *) haystack + haystack_len - needle_len;
if (needle_len == 0)
/* The first occurrence of the empty string is deemed to occur at
the end of the string. */
return (PTR) &((CONST char *) haystack)[haystack_len - 1];
for (begin = (CONST char *) haystack; begin <= last_possible; ++begin)
if (begin[0] == ((CONST char *) needle)[0] &&
!memcmp ((CONST PTR) &begin[1],
(CONST PTR) ((CONST char *) needle + 1),
needle_len - 1))
return (PTR) begin;
return NULL;
}
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