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.\"     @(#)memcpy.3	8.1 (Berkeley) 6/4/93
.\"
.Dd November 18, 2023
.Dt MEMCPY 3
.Os
.Sh NAME
.Nm memcpy
.Nd copy byte string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In string.h
.Ft void *
.Fn memcpy "void *dst" "const void *src" "size_t len"
.Ft void *
.Fn mempcpy "void *dst" "const void *src" "size_t len"
.Sh DESCRIPTION
The
.Fn memcpy
and
.Fn mempcpy
functions
copy
.Fa len
bytes from string
.Fa src
to string
.Fa dst .
If
.Fa src
and
.Fa dst
overlap, the results are not defined.
.Sh RETURN VALUES
The
.Fn memcpy
function
returns the original value of
.Fa dst .
.Pp
The
.Fn mempcpy
function returns a pointer to the byte after the last written byte.
.Sh SEE ALSO
.Xr bcopy 3 ,
.Xr memccpy 3 ,
.Xr memmove 3 ,
.Xr strcpy 3 ,
.Xr wmemcpy 3 ,
.Xr wmempcpy 3
.Sh STANDARDS
The
.Fn memcpy
function
conforms to
.St -isoC .
.Sh HISTORY
The
.Fn memcpy
function first appeared in
.At V
and was reimplemented for
.Bx 4.3 Tahoe .
The
.Fn mempcpy
function first appeared in
.Fx 13.1 .