xref: /openbsd-src/gnu/usr.bin/texinfo/lib/memmove.c (revision 8500990981f885cbe5e6a4958549cacc238b5ae6)
1 /* memmove.c -- copy memory.
2    Copy LENGTH bytes from SOURCE to DEST.  Does not null-terminate.
3    In the public domain.
4    By David MacKenzie <djm@gnu.ai.mit.edu>.  */
5 
6 #if HAVE_CONFIG_H
7 # include <config.h>
8 #endif
9 
10 void *
11 memmove (dest, source, length)
12      char *dest;
13      const char *source;
14      unsigned length;
15 {
16   char *d0 = dest;
17   if (source < dest)
18     /* Moving from low mem to hi mem; start at end.  */
19     for (source += length, dest += length; length; --length)
20       *--dest = *--source;
21   else if (source != dest)
22     {
23       /* Moving from hi mem to low mem; start at beginning.  */
24       for (; length; --length)
25 	*dest++ = *source++;
26     }
27   return (void *) d0;
28 }
29