glibc/sysdeps/generic/memmem.c
Ulrich Drepper 4775243aa8 Update.
1998-01-28  Andreas Jaeger  <aj@arthur.rhein-neckar.de>

	* manual/memory.texi (Heap Consistency Checking): mcheck is
	declared in <mcheck.h>.
	Suggested by Jochen Voss <voss@mathematik.uni-kl.de> [PR libc/438]

1998-01-28  Andreas Jaeger  <aj@arthur.rhein-neckar.de>

	* sysdeps/generic/memmem.c (memmem): An empty needle is at the
	beginning of haystack.

1998-01-29  Andreas Jaeger  <aj@arthur.rhein-neckar.de>

	* nss/nss_files/files-service.c: Correct last patch.

1998-01-30 21:29  Ulrich Drepper  <drepper@cygnus.com>

	* sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c: Define
	__libc_have_rt_sigs.
	* sysdeps/sparc/sparc32/__longjmp.S: Define _SETJMP_H before
	including <bits/setjmp.h>.
	* sysdeps/sparc/sparc32/setjmp.S: Likewise.
	Patch from the Debian glibc/SPARC package.

1997-12-12 07:57  H.J. Lu  <hjl@gnu.org>

	* sysdeps/alpha/bzero.S: Fix a typo.
	* sysdeps/alpha/htonl.S: Ditto.
	* sysdeps/alpha/htons.S: Ditto.
1998-01-30 12:53:20 +00:00

50 lines
1.7 KiB
C

/* Copyright (C) 1991, 92, 93, 94, 96, 97, 98 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. */
#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 *) &((const char *) haystack);
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;
}