.\"	$OpenBSD: memmem.3,v 1.4 2024/08/03 20:13:23 guenther Exp $
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.\" Copyright (c) 2005 Pascal Gloor <pascal.gloor@spale.com>
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.Dd $Mdocdate: August 3 2024 $
.Dt MEMMEM 3
.Os
.Sh NAME
.Nm memmem
.Nd locate a byte substring in a byte string
.Sh SYNOPSIS
.In string.h
.Ft "void *"
.Fo memmem
.Fa "const void *big" "size_t big_len"
.Fa "const void *little" "size_t little_len"
.Fc
.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 little
is zero length,
.Fa big
is returned; 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 STANDARDS
The
.Fn memmem
function conforms to
.St -p1003.1-2024 .
.Sh HISTORY
The
.Fn memmem
function first appeared in
.Ox 5.4 .