1: # include <stdio.h> 2: # include <ctype.h> 3: 4: # define reg register 5: 6: # define makelower(c) (isupper(c) ? tolower(c) : c) 7: 8: /* 9: * Compare strings: s1>s2: >0 s1==s2: 0 s1<s2: <0 10: */ 11: 12: strcmp(s1, s2) 13: reg char *s1, *s2; { 14: 15: while (makelower(*s1) == makelower(*s2)) { 16: if (*s1 == '\0') 17: return 0; 18: s1++, s2++; 19: } 20: return *s1 - *s2; 21: }