string/FreeBSD/memcpy.3

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  36 .\"     @(#)memcpy.3    8.1 (Berkeley) 6/4/93
  37 .\" $FreeBSD: src/lib/libc/string/memcpy.3,v 1.7 2002/01/07 06:03:37 dd Exp $
  38 .\"
  39 .Dd June 4, 1993
  40 .Dt MEMCPY 3
  41 .Os
  42 .Sh NAME
  43 .Nm memcpy
  44 .Nd copy byte string
  45 .Sh LIBRARY
  46 .Lb libc
  47 .Sh SYNOPSIS
  48 .In string.h
  49 .Ft void *
  50 .Fn memcpy "void *dst" "const void *src" "size_t len"
  51 .Sh DESCRIPTION
  52 The
  53 .Fn memcpy
  54 function
  55 copies
  56 .Fa len
  57 bytes from string
  58 .Fa src
  59 to string
  60 .Fa dst .
  61 .Sh RETURN VALUES
  62 The
  63 .Fn memcpy
  64 function
  65 returns the original value of
  66 .Fa dst .
  67 .Sh SEE ALSO
  68 .Xr bcopy 3 ,
  69 .Xr memccpy 3 ,
  70 .Xr memmove 3 ,
  71 .Xr strcpy 3
  72 .Sh STANDARDS
  73 The
  74 .Fn memcpy
  75 function
  76 conforms to
  77 .St -isoC .
  78 .Sh BUGS
  79 In this implementation
  80 .Fn memcpy
  81 is implemented using
  82 .Xr bcopy 3 ,
  83 and therefore the strings may overlap.
  84 On other systems, copying overlapping strings may produce surprises.
  85 Programs intended to be portable should use
  86 .Xr memmove 3
  87 when
  88 .Fa src
  89 and
  90 .Fa dst
  91 may overlap.