ref: b3ac093c1354d52c062b70d3efe60e17dafb5f54
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;
}