8 int strcasecmp(const char *s1, const char *s2)
10 const unsigned char *c1 = s1, *c2 = s2;
15 /* toupper() expects an unsigned char (implicitly cast to int)
16 as input, and returns an int, which is exactly what we want. */
17 d = toupper(ch = *c1++) - toupper(*c2++);