gnu/dist/texinfo/lib/memmove.c

   1 /*      $NetBSD$        */
   2
   3 /* memmove.c -- copy memory.
   4    Copy LENGTH bytes from SOURCE to DEST.  Does not null-terminate.
   5    In the public domain.
   6    By David MacKenzie <djm@gnu.ai.mit.edu>.  */
   7
   8 #if HAVE_CONFIG_H
   9 # include <config.h>
  10 #endif
  11
  12 #include <stddef.h>
  13
  14 void *
  15 memmove (void *dest0, void const *source0, size_t length)
  16 {
  17   char *dest = dest0;
  18   char const *source = source0;
  19   if (source < dest)
  20     /* Moving from low mem to hi mem; start at end.  */
  21     for (source += length, dest += length; length; --length)
  22       *--dest = *--source;
  23   else if (source != dest)
  24     {
  25       /* Moving from hi mem to low mem; start at beginning.  */
  26       for (; length; --length)
  27         *dest++ = *source++;
  28     }
  29   return dest0;
  30 }