37296464de
The removed text claimed that memcpy is implemented using bcopy and thus strings may overlap. Use of bcopy is an implementation detail that is no longer true, even if the implementation (on some archs) does allow overlap. In any case behaviour is undefined per the C standard if memcpy is called with overlapping objects, and this man page already claimed that src and dst may not overlap. Reviewed by: kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D31192
89 lines
2.6 KiB
Groff
89 lines
2.6 KiB
Groff
.\" Copyright (c) 1990, 1991, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" This code is derived from software contributed to Berkeley by
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.\" Chris Torek and the American National Standards Committee X3,
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.\" on Information Processing Systems.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)memcpy.3 8.1 (Berkeley) 6/4/93
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.\" $FreeBSD$
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.\"
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.Dd July 14, 2021
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.Dt MEMCPY 3
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.Os
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.Sh NAME
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.Nm memcpy
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.Nd copy byte string
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.Sh LIBRARY
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.Lb libc
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.Sh SYNOPSIS
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.In string.h
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.Ft void *
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.Fn memcpy "void *dst" "const void *src" "size_t len"
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.Ft void *
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.Fn mempcpy "void *dst" "const void *src" "size_t len"
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.Sh DESCRIPTION
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The
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.Fn memcpy
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and
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.Fn mempcpy
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functions
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copy
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.Fa len
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bytes from string
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.Fa src
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to string
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.Fa dst .
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If
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.Fa src
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and
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.Fa dst
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overlap, the results are not defined.
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.Sh RETURN VALUES
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The
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.Fn memcpy
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function
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returns the original value of
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.Fa dst .
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.Pp
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The
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.Fn mempcpy
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function returns a pointer to the byte after the last written byte.
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.Sh SEE ALSO
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.Xr bcopy 3 ,
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.Xr memccpy 3 ,
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.Xr memmove 3 ,
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.Xr strcpy 3 ,
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.Xr wmemcpy 3
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.Xr wmempcpy 3
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.Sh STANDARDS
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The
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.Fn memcpy
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function
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conforms to
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.St -isoC .
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