1.\" $NetBSD: memmem.3,v 1.2 2005/03/14 10:36:51 wiz Exp $ 2.\" 3.\" Copyright (c) 2005 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Perry E. Metzger of Metzger, Dowdeswell & Co. LLC. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.Dd March 12, 2005 38.Dt MEMMEM 3 39.Os 40.Sh NAME 41.Nm memmem 42.Nd locate substring in byte string 43.Sh LIBRARY 44.Lb libc 45.Sh SYNOPSIS 46.In string.h 47.Ft void * 48.Fn memmem "const void *block" "size_t blen" "const void *pat" "size_t plen" 49.Sh DESCRIPTION 50The 51.Fn memmem 52function locates the first occurrence of the binary string 53.Fa pat 54of size 55.Fa plen 56bytes in the byte string 57.Fa block 58of size 59.Fa blen 60bytes. 61.Sh RETURN VALUES 62The 63.Fn memmem 64function returns a pointer to the substring located, or 65.Dv NULL 66if no such substring exists within 67.Fa block . 68.Pp 69If 70.Fa plen 71is zero, 72.Fa block 73is returned, i.e. a zero length 74.Fa pat 75is deemed to match the start of the string, as with 76.Xr strstr 3 . 77.Sh SEE ALSO 78.Xr bm 3 , 79.Xr memchr 3 , 80.Xr strchr 3 , 81.Xr strstr 3 82.Sh STANDARDS 83The 84.Fn memmem 85function is not currently standardized. 86However, it is meant to be API compatible with functions in 87.Fx 88and Linux. 89.Sh HISTORY 90.Fn memmem 91first appeared in the Free Software Foundation's glibc library. 92