glibc/sysdeps/generic/memmem.c
Andreas Jaeger 41bdb6e20c Update to LGPL v2.1.
2001-07-06  Paul Eggert  <eggert@twinsun.com>

	* manual/argp.texi: Remove ignored LGPL copyright notice; it's
	not appropriate for documentation anyway.
	* manual/libc-texinfo.sh: "Library General Public License" ->
	"Lesser General Public License".

2001-07-06  Andreas Jaeger  <aj@suse.de>

	* All files under GPL/LGPL version 2: Place under LGPL version
	2.1.
2001-07-06 04:58:11 +00:00

55 lines
1.8 KiB
C

/* Copyright (C) 1991,92,93,94,96,97,98,2000 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 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <stddef.h>
#include <string.h>
#undef memmem
/* Return the first occurrence of NEEDLE in HAYSTACK. */
void *
memmem (haystack, haystack_len, needle, needle_len)
const void *haystack;
size_t haystack_len;
const void *needle;
size_t needle_len;
{
const char *begin;
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 beginning of the string. */
return (void *) haystack;
/* Sanity check, otherwise the loop might search through the whole
memory. */
if (__builtin_expect (haystack_len < needle_len, 0))
return NULL;
for (begin = (const char *) haystack; begin <= last_possible; ++begin)
if (begin[0] == ((const char *) needle)[0] &&
!memcmp ((const void *) &begin[1],
(const void *) ((const char *) needle + 1),
needle_len - 1))
return (void *) begin;
return NULL;
}