#include <stdio.h>


int strcmp( char s1[], char s2[] )
{
   int r;

   /* ----------------------------------
      '\0' marks the end of the string !
      ---------------------------------- */
   while ( *s1 != '\0' && *s2 != '\0' && (r = (*s1++ - *s2++)) == 0 );

   /* ----------------------------------------------------------------
      If we reach here, then 

           1. one or both of s1 and s2 are exhausted !
        or 2. r != 0
      ---------------------------------------------------------------- */

   return (r != 0) ? r : (*s1 - *s2); 
}

int main(int argc, char *arg[])
{
   char a[] = "Hell";
   char b[] = "Hello";
   char c[] = "Helloe";

   
   printf("strcmp(%s, %s) = %d\n", b, b, strcmp(b, b) );
   printf("strcmp(%s, %s) = %d\n", b, a, strcmp(b, a) );
   printf("strcmp(%s, %s) = %d\n", b, c, strcmp(b, c) );

}