cpython/Python/memmove.c

35 lines
879 B
C

/***********************************************************
Copyright (c) 2000, BeOpen.com.
Copyright (c) 1995-2000, Corporation for National Research Initiatives.
Copyright (c) 1990-1995, Stichting Mathematisch Centrum.
All rights reserved.
See the file "Misc/COPYRIGHT" for information on usage and
redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
******************************************************************/
/* 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;
}