Python/memmove.c

   1
   2 /* A perhaps slow but I hope correct implementation of memmove */
   3
   4 extern char *memcpy(char *, char *, int);
   5
   6 char *
   7 memmove(char *dst, char *src, int n)
   8 {
   9         char *realdst = dst;
  10         if (n <= 0)
  11                 return dst;
  12         if (src >= dst+n || dst >= src+n)
  13                 return memcpy(dst, src, n);
  14         if (src > dst) {
  15                 while (--n >= 0)
  16                         *dst++ = *src++;
  17         }
  18         else if (src < dst) {
  19                 src += n;
  20                 dst += n;
  21                 while (--n >= 0)
  22                         *--dst = *--src;
  23         }
  24         return realdst;
  25 }