man3/mempcpy.3

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