/* * Compare strings (at most n bytes): s1>s2: >0 s1==s2: 0 s1<s2: <0 */ strncmp(s1, s2, n) register char *s1, *s2; register n; { while (--n >= 0 && *s1 == *s2++) if (*s1++ == '\0') return(0); return(n<0 ? 0 : *s1 - *--s2); }