head

1. mark the prototype
   //_PROTOTYPE(int head_main, (int argc, char **argv));
   //_PROTOTYPE(void do_file, (int n, FILE *f));
   //_PROTOTYPE(void usage, (void));
   
2. change the function to
   int main(int argc,char *argv[])
   void do_file(int n,FILE *f)
   
3. Reference
   
   1. head.c