1.\" $NetBSD: memcpy.9,v 1.10 2017/03/18 19:01:01 riastradh Exp $ 2.\" 3.\" Copyright (c) 1990, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" Chris Torek and the American National Standards Committee X3, 8.\" on Information Processing Systems. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" from: @(#)memcpy.3 8.1 (Berkeley) 6/4/93 35.\" 36.Dd January 2, 2012 37.Dt MEMCPY 9 38.Os 39.Sh NAME 40.Nm memcpy 41.Nd copy byte string 42.Sh SYNOPSIS 43.In sys/systm.h 44.Ft void * 45.Fn memcpy "void * restrict dst" "const void * restrict src" "size_t len" 46.Sh DESCRIPTION 47The 48.Fn memcpy 49function 50copies 51.Fa len 52bytes from string 53.Fa src 54to string 55.Fa dst . 56The arguments must not overlap \(em behavior if the arguments overlap 57is undefined. 58To copy byte strings that overlap, use 59.Xr memmove 9 . 60.Sh RETURN VALUES 61The 62.Fn memcpy 63function 64returns the original value of 65.Fa dst . 66.Sh SEE ALSO 67.Xr memmove 9 68.Sh STANDARDS 69The 70.Fn memcpy 71function 72conforms to 73.St -isoC-99 . 74