file_open
if (!file_open)
file_open = 0;
if (!file_open)
file_open = 1;
int file_open; /* If a file open. */
FILE *mapf = file_open(map, tp);
FILE *mapf = file_open(map, (time_t *) 0);
FILE *mapf = file_open(map, &t);
FILE *mapf = file_open(map, tp);