Files
lbmk/util/sbase/libutil/memmem.c
Leah Rowe e9a910b33c config/git: import suckless sbase
i currently use the output of sha512sum in several
places of xbmk, which is a bit unreliable in case
output changes.

other cases where i use util outputs in variables
are probably reliable, because i'm using mostly
posix utilities in those.

to mitigate this, i now import suckless sbase, which
has a reasonable sha512sum implementation.

*every* binary it builds is being placed in build.list,
because i'll probably start using more of them.

for example, i may start modifying the "date"
implementation, adding the GNU-specific options that
i need as mentioned on init.sh

i'm importing it in util/ because the sha512sum
util is needed for verifying project sources, so
if sbase itself is a "project source", that means
we can into a chicken and egg bootstrapping problem.

this is sbase at revision:
055cc1ae1b3a13c3d8f25af0a4a3316590efcd48

Signed-off-by: Leah Rowe <leah@libreboot.org>
2025-10-04 09:20:12 +01:00

67 lines
2.3 KiB
C

/* $OpenBSD: memmem.c,v 1.4 2015/08/31 02:53:57 guenther Exp $ */
/*
* Copyright (c) 2005 Pascal Gloor <pascal.gloor@spale.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <string.h>
#include "../util.h"
/*
* Find the first occurrence of the byte string s in byte string l.
*/
void *
memmem(const void *l, size_t l_len, const void *s, size_t s_len)
{
const char *cur, *last;
const char *cl = l;
const char *cs = s;
/* a zero length needle should just return the haystack */
if (s_len == 0)
return (void *)cl;
/* "s" must be smaller or equal to "l" */
if (l_len < s_len)
return NULL;
/* special case where s_len == 1 */
if (s_len == 1)
return memchr(l, *cs, l_len);
/* the last position where its possible to find "s" in "l" */
last = cl + l_len - s_len;
for (cur = cl; cur <= last; cur++)
if (cur[0] == cs[0] && memcmp(cur, cs, s_len) == 0)
return (void *)cur;
return NULL;
}