1.\" $OpenBSD: memcpy.3,v 1.10 2013/06/05 03:39:23 tedu Exp $ 2.\" 3.\" Copyright (c) 1990, 1991 The Regents of the University of California. 4.\" 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.Dd $Mdocdate: June 5 2013 $ 35.Dt MEMCPY 3 36.Os 37.Sh NAME 38.Nm memcpy 39.Nd copy bytes 40.Sh SYNOPSIS 41.In string.h 42.Ft void * 43.Fn memcpy "void *dst" "const void *src" "size_t len" 44.Sh DESCRIPTION 45The 46.Fn memcpy 47function copies 48.Fa len 49bytes from buffer 50.Fa src 51to buffer 52.Fa dst . 53If the two buffers may overlap, 54.Xr memmove 3 55must be used instead. 56.Sh RETURN VALUES 57The 58.Fn memcpy 59function returns the original value of 60.Fa dst . 61.Sh SEE ALSO 62.Xr bcopy 3 , 63.Xr memccpy 3 , 64.Xr memmove 3 , 65.Xr strcpy 3 , 66.Xr strlcpy 3 , 67.Xr wmemcpy 3 68.Sh STANDARDS 69The 70.Fn memcpy 71function conforms to 72.St -ansiC . 73.Sh HISTORY 74The 75.Fn memcpy 76function first appeared in 77.At V 78and was reimplemented for 79.Bx 4.3 Tahoe . 80