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[dragonfly.git] / lib / libc / string / memcpy.3
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1.\" Copyright (c) 1990, 1991, 1993
2.\" The Regents of the University of California. All rights reserved.
3.\"
4.\" This code is derived from software contributed to Berkeley by
5.\" Chris Torek and the American National Standards Committee X3,
6.\" on Information Processing Systems.
7.\"
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9.\" modification, are permitted provided that the following conditions
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12.\" notice, this list of conditions and the following disclaimer.
13.\" 2. Redistributions in binary form must reproduce the above copyright
14.\" notice, this list of conditions and the following disclaimer in the
15.\" documentation and/or other materials provided with the distribution.
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16.\" 4. Neither the name of the University nor the names of its contributors
17.\" may be used to endorse or promote products derived from this software
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19.\"
20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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31.\"
32.\" @(#)memcpy.3 8.1 (Berkeley) 6/4/93
716024cd 33.\" $FreeBSD: src/lib/libc/string/memcpy.3,v 1.8 2007/01/09 00:28:12 imp Exp $
1de703da 34.\" $DragonFly: src/lib/libc/string/memcpy.3,v 1.2 2003/06/17 04:26:46 dillon Exp $
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35.\"
36.Dd June 4, 1993
37.Dt MEMCPY 3
38.Os
39.Sh NAME
40.Nm memcpy
41.Nd copy byte string
42.Sh LIBRARY
43.Lb libc
44.Sh SYNOPSIS
45.In string.h
46.Ft void *
47.Fn memcpy "void *dst" "const void *src" "size_t len"
48.Sh DESCRIPTION
49The
50.Fn memcpy
51function
52copies
53.Fa len
54bytes from string
55.Fa src
56to string
57.Fa dst .
58.Sh RETURN VALUES
59The
60.Fn memcpy
61function
62returns the original value of
63.Fa dst .
64.Sh SEE ALSO
65.Xr bcopy 3 ,
66.Xr memccpy 3 ,
67.Xr memmove 3 ,
68.Xr strcpy 3
69.Sh STANDARDS
70The
71.Fn memcpy
72function
73conforms to
74.St -isoC .
75.Sh BUGS
76In this implementation
77.Fn memcpy
78is implemented using
79.Xr bcopy 3 ,
80and therefore the strings may overlap.
81On other systems, copying overlapping strings may produce surprises.
82Programs intended to be portable should use
83.Xr memmove 3
84when
85.Fa src
86and
87.Fa dst
88may overlap.