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/* $Id: memcmp.c 5049 2001-12-12 09:06:00Z rra $
**
** Replacement for a missing or broken memcmp.
**
** Written by Russ Allbery <rra@stanford.edu>
** This work is hereby placed in the public domain by its author.
**
** Provides the same functionality as the standard library routine memcmp
** for those platforms that don't have it or where it doesn't work right
** (such as on SunOS where it can't deal with eight-bit characters).
*/
#include "config.h"
#include <sys/types.h>
/* If we're running the test suite, rename memcmp to avoid conflicts with
the system version. */
#if TESTING
# define memcmp test_memcmp
int test_memcmp(const void *, const void *, size_t);
#endif
int
memcmp(const void *s1, const void *s2, size_t n)
{
size_t i;
const unsigned char *p1, *p2;
/* It's technically illegal to call memcmp with NULL pointers, but we
may as well check anyway. */
if (!s1)
return !s2 ? 0 : -1;
if (!s2)
return 1;
p1 = (const unsigned char *) s1;
p2 = (const unsigned char *) s2;
for (i = 0; i < n; i++, p1++, p2++)
if (*p1 != *p2)
return (int) *p1 - (int) *p2;
return 0;
}
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