man3/mempcpy.3

   1 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
   2 .\"
   3 .\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
   4 .\" Distributed under GPL
   5 .\" %%%LICENSE_END
   6 .\"
   7 .\" Heavily based on glibc infopages, copyright Free Software Foundation
   8 .\"
   9 .\" aeb, 2003, polished a little
  10 .TH MEMPCPY 3 2008-08-12 "GNU" "Linux Programmer's Manual"
  11 .SH NAME
  12 mempcpy, wmempcpy  \- copy memory area
  13 .SH SYNOPSIS
  14 .nf
  15 .BR "#define _GNU_SOURCE" "         /* See feature_test_macros(7) */"
  16 .br
  17 .B #include <string.h>
  18 .sp
  19 .BI "void *mempcpy(void *" dest ", const void *" src ", size_t " n );
  20 .sp
  21 .BR "#define _GNU_SOURCE" "         /* See feature_test_macros(7) */"
  22 .br
  23 .B #include <wchar.h>
  24 .sp
  25 .BI "wchar_t *wmempcpy(wchar_t *" dest ", const wchar_t *" src ", size_t " n );
  26 .fi
  27 .SH DESCRIPTION
  28 The
  29 .BR mempcpy ()
  30 function is nearly identical to the
  31 .BR memcpy (3)
  32 function.
  33 It copies
  34 .I n
  35 bytes from the object beginning at
  36 .I src
  37 into the object pointed to by
  38 .IR dest .
  39 But instead of returning the value of
  40 .I dest
  41 it returns a pointer to the byte following the last written byte.
  42 .PP
  43 This function is useful in situations where a number of objects
  44 shall be copied to consecutive memory positions.
  45 .PP
  46 The
  47 .BR wmempcpy ()
  48 function is identical but takes
  49 .I wchar_t
  50 type arguments and copies
  51 .I n
  52 wide characters.
  53 .SH RETURN VALUE
  54 \fIdest\fP + \fIn\fP.
  55 .SH VERSIONS
  56 .BR mempcpy ()
  57 first appeared in glibc in version 2.1.
  58 .SH CONFORMING TO
  59 This function is a GNU extension.
  60 .SH EXAMPLE
  61 .nf
  62 void *
  63 combine(void *o1, size_t s1, void *o2, size_t s2)
  64 {
  65     void *result = malloc(s1 + s2);
  66     if (result != NULL)
  67         mempcpy(mempcpy(result, o1, s1), o2, s2);
  68     return result;
  69 }
  70 .fi
  71 .SH SEE ALSO
  72 .BR memccpy (3),
  73 .BR memcpy (3),
  74 .BR memmove (3),
  75 .BR wmemcpy (3)