.\" $NetBSD: memmem.3,v 1.3 2008/04/30 13:10:51 martin Exp $ .\" .\" Copyright (c) 2005 The NetBSD Foundation, Inc. .\" All rights reserved. .\" .\" This code is derived from software contributed to The NetBSD Foundation .\" by Perry E. Metzger of Metzger, Dowdeswell & Co. LLC. .\" .\" 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. .\" .\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. .\" .Dd March 12, 2005 .Dt MEMMEM 3 .Os .Sh NAME .Nm memmem .Nd locate substring in byte string .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In string.h .Ft void * .Fn memmem "const void *block" "size_t blen" "const void *pat" "size_t plen" .Sh DESCRIPTION The .Fn memmem function locates the first occurrence of the binary string .Fa pat of size .Fa plen bytes in the byte string .Fa block of size .Fa blen bytes. .Sh RETURN VALUES The .Fn memmem function returns a pointer to the substring located, or .Dv NULL if no such substring exists within .Fa block . .Pp If .Fa plen is zero, .Fa block is returned, i.e. a zero length .Fa pat is deemed to match the start of the string, as with .Xr strstr 3 . .Sh SEE ALSO .Xr bm 3 , .Xr memchr 3 , .Xr strchr 3 , .Xr strstr 3 .Sh STANDARDS The .Fn memmem function is not currently standardized. However, it is meant to be API compatible with functions in .Fx and Linux. .Sh HISTORY .Fn memmem first appeared in the Free Software Foundation's glibc library.