#include <stdio.h>

int main (int argc, char **argv)
{
  if (argc != 3) {
    printf ("Usage: copy <source-file> <destination-file>\n");
    exit (0);
  }

  printf ("Copying from %s to %s ... \n", argv[1], argv[2]);

  // ... Do actual copying ...

  printf ("... done\n");
}