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.\"     @(#)bcopy.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD: head/lib/libc/string/bcopy.3 287089 2015-08-24 01:53:18Z araujo $
.\"
.Dd August 24, 2015
.Dt BCOPY 3
.Os
.Sh NAME
.Nm bcopy
.Nd copy byte string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In strings.h
.Ft void
.Fn bcopy "const void *src" "void *dst" "size_t len"
.Sh DESCRIPTION
The
.Fn bcopy
function
copies
.Fa len
bytes from string
.Fa src
to string
.Fa dst .
The two strings may overlap.
If
.Fa len
is zero, no bytes are copied.
.Sh SEE ALSO
.Xr memccpy 3 ,
.Xr memcpy 3 ,
.Xr memmove 3 ,
.Xr strcpy 3 ,
.Xr strncpy 3
.Sh HISTORY
A
.Fn bcopy
function appeared in
.Bx 4.2 .
Its prototype existed previously in
.In string.h
before it was moved to
.In strings.h
for
.St -p1003.1-2001
compliance.
.Pp
.St -p1003.1-2008
removes the specification of
.Fn bcopy
and it is marked as LEGACY in
.St -p1003.1-2004 .
New programs should use
.Xr memmove 3 .
If the input and output buffer do not overlap, then
.Xr memcpy 3
is more efficient.
Note that
.Fn bcopy
takes
.Ar src
and
.Ar dst
in the opposite order from
.Fn memmove
and
.Fn memcpy .