source: vendor/python/2.5/Python/memmove.c

/* A perhaps slow but I hope correct implementation of memmove */

extern char *memcpy(char *, char *, int);

char *
memmove(char *dst, char *src, int n)
{
        char *realdst = dst;
        if (n <= 0)
                return dst;
        if (src >= dst+n || dst >= src+n)
                return memcpy(dst, src, n);
        if (src > dst) {
                while (--n >= 0)
                        *dst++ = *src++;
        }
        else if (src < dst) {
                src += n;
                dst += n;
                while (--n >= 0)
                        *--dst = *--src;
        }
        return realdst;
}