#include <stdio.h>

int main (int argc, char **argv) {
   switch (argc) {
      case 0: fprintf (stderr, "This can't happen.\n");
              break;
      case 1: printf ("No args to program %s.\n", argv[0]);
              break;
      case 2: printf ("Only the arg %s was passed to program %s.\n",
                      argv[1], argv[0]);
              break;
      case 3: printf ("%s %s\n", argv[2], argv[1]);
              break;
      default: printf ("Too many args.\n");
      }
   return 0;
   }