ref: 0a7dad2565a39f1d4d57cc0406fe236709d6b847
dir: /lib/c/strcmp.c/
#include <string.h>
#undef strcmp
int
strcmp(const char *s1, const char *s2)
{
while (*s1 && *s2 && *s1 == *s2)
++s1, ++s2;
return *(unsigned char *)s1 - *(unsigned char *)s2;
}