Add the function memmem(3) as found in glibc and others.

It is the binary equivalent to strstr(3).

 void *memmem(const void *big, size_t big_len,
	const void *little, size_t little_len);

Submitted by:	Pascal Gloor <pascal.gloor at spale.com>
MFC after:	3 days
This commit is contained in:
Andre Oppermann 2005-08-25 18:26:58 +00:00
parent 7a481a4f28
commit 6050c8fe05
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=149466
7 changed files with 160 additions and 5 deletions

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@ -61,6 +61,7 @@ void *memccpy(void * __restrict, const void * __restrict, int, size_t);
void *memchr(const void *, int, size_t) __pure;
int memcmp(const void *, const void *, size_t) __pure;
void *memcpy(void * __restrict, const void * __restrict, size_t);
void *memmem(const void *, size_t, const void *, size_t);
void *memmove(void *, const void *, size_t);
void *memset(void *, int, size_t);
#if __BSD_VISIBLE

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@ -8,10 +8,10 @@ CFLAGS+= -I${.CURDIR}/locale
# machine-independent string sources
MISRCS+=bcmp.c bcopy.c bzero.c ffs.c ffsl.c fls.c flsl.c index.c memccpy.c \
memchr.c memcmp.c \
memcpy.c memmove.c memset.c rindex.c stpcpy.c strcasecmp.c strcat.c \
strchr.c strcmp.c strcoll.c strcpy.c strcspn.c strdup.c strerror.c \
strlcat.c strlcpy.c strlen.c strmode.c strncat.c strncmp.c strncpy.c \
strcasestr.c strnstr.c \
memcpy.c memmem.c memmove.c memset.c rindex.c stpcpy.c strcasecmp.c \
strcat.c strchr.c strcmp.c strcoll.c strcpy.c strcspn.c strdup.c \
strerror.c strlcat.c strlcpy.c strlen.c strmode.c strncat.c strncmp.c \
strncpy.c strcasestr.c strnstr.c \
strpbrk.c strrchr.c strsep.c strsignal.c strspn.c strstr.c strtok.c \
strxfrm.c swab.c wcscat.c wcschr.c wcscmp.c wcscoll.c wcscpy.c \
wcscspn.c wcsdup.c \
@ -27,7 +27,7 @@ MISRCS+=bcmp.c bcopy.c bzero.c ffs.c ffsl.c fls.c flsl.c index.c memccpy.c \
.endif
MAN+= bcmp.3 bcopy.3 bstring.3 bzero.3 ffs.3 index.3 memccpy.3 memchr.3 \
memcmp.3 memcpy.3 memmove.3 memset.3 strcasecmp.3 strcat.3 \
memcmp.3 memcpy.3 memmem.3 memmove.3 memset.3 strcasecmp.3 strcat.3 \
strchr.3 strcmp.3 strcoll.3 strcpy.3 strcspn.3 strdup.3 strerror.3 \
string.3 strlcpy.3 strlen.3 strmode.3 strpbrk.3 strsep.3 \
strspn.3 strstr.3 strtok.3 strxfrm.3 swab.3 wcscoll.3 wcstok.3 \

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@ -66,6 +66,7 @@ or NULL if no such byte exists within
.Fa len
bytes.
.Sh SEE ALSO
.Xr memmem 3 ,
.Xr strchr 3 ,
.Xr strcspn 3 ,
.Xr strpbrk 3 ,

84
lib/libc/string/memmem.3 Normal file
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@ -0,0 +1,84 @@
.\" 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.
.\"
\" $FreeBSD$
.\"
.Dd August 24, 2005
.Dt MEMMEM 3
.Os
.Sh NAME
.Nm memmem
.Nd locate a byte substring in a byte string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In string.h
.Ft void *
.Fn memmem "const char *big" "size_t big_len" \
"const char *little" "size_t little_len"
.Sh DESCRIPTION
The
.Fn memmem
function
locates the first occurrence of the byte string
.Fa little
in the byte string
.Fa big .
.Sh RETURN VALUES
If
.Fa big_len
is smaller than
.Fa little_len ,
if
.Fa little_len
is 0, if
.Fa big_len
is 0 or if
.Fa little
occurs nowhere in
.Fa big ,
.Dv NULL
is returned;
otherwise a pointer to the first character of the first occurrence of
.Fa little
is returned.
.Sh SEE ALSO
.Xr memchr 3 ,
.Xr strchr 3 ,
.Xr strstr 3
.Sh CONFORMING TO
.Fn memmem
is a GNU extension.
.Sh HISTORY
The
.Fn memmem
function first appeared in
.Fx 6.0 .
.Sh AUTHOR
Pascal Gloor <pascal.gloor@spale.com>
.Sh BUGS
This function was broken in Linux libc up to and including version 5.0.9
and in GNU libc prior to version 2.1.

67
lib/libc/string/memmem.c Normal file
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@ -0,0 +1,67 @@
/*-
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <string.h>
/*
* Find the first occurrence of the byte string s in byte string l.
*/
void *
memmem(l, l_len, s, s_len)
const void *l; size_t l_len;
const void *s; size_t s_len;
{
register char *cur, *last;
const char *cl = (const char *)l;
const char *cs = (const char *)s;
/* we need something to compare */
if (l_len == 0 || s_len == 0)
return NULL;
/* "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, (int)*cs, l_len);
/* the last position where its possible to find "s" in "l" */
last = (char *)cl + l_len - s_len;
for (cur = (char *)cl; cur <= last; cur++)
if (cur[0] == cs[0] && memcmp(cur, cs, s_len) == 0)
return cur;
return NULL;
}

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@ -83,6 +83,7 @@ return a pointer to the located character, or
if the character does not appear in the string.
.Sh SEE ALSO
.Xr memchr 3 ,
.Xr memmem 3 ,
.Xr strcspn 3 ,
.Xr strpbrk 3 ,
.Xr strsep 3 ,

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@ -132,6 +132,7 @@ ptr = strnstr(largestring, smallstring, 4);
.Ed
.Sh SEE ALSO
.Xr memchr 3 ,
.Xr memmem 3 ,
.Xr strchr 3 ,
.Xr strcspn 3 ,
.Xr strpbrk 3 ,