int main(int argc, char *argv[])
{
 if(argc < 3) die("USAGE: ex17 <dbfile> <action> [action params]");
 char *filename = argv[1];
 char action = argv[2][0];
 struct Connection *conn = Database_open(filename, action);
 int id = 0;
 if(argc > 3) id = atoi(argv[3]);
 if(id >= MAX_ROWS) die("There's not that many records.");
 switch(action) {
 case 'c':
 Database_create(conn);
 Database_write(conn);
 break;
 case 'g':
 if(argc != 4) die("Need an id to get");
 Database_get(conn, id);
 break;
 case 's':
 if(argc != 6) die("Need id, name, email to set");
 Database_set(conn, id, argv[4], argv[5]);
 Database_write(conn);
 break;
 case 'd':
 if(argc != 4) die("Need id to delete");
 Database_delete(conn, id);
 Database_write(conn);
 break;
 case 'l':
 Database_list(conn);
 break;
 default:
 die("Invalid action, only: c=create, g=get, s=set, d=del, l=list");
 }
 Database_close(conn);
 return 0;
}