blob: 83abaffb59bba55546babe861a22d23079aecf9c [file] [log] [blame]
Erik Andersen31638212000-01-15 22:28:50 +00001/*
2 * Mini tty implementation for busybox
3 *
4 * Copyright (C) 2000 Edward Betts <edward@debian.org>.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22#include "internal.h"
23#include <stdio.h>
24#include <sys/types.h>
25
26static const char tty_usage[] = "tty\n\n"
27"Print the file name of the terminal connected to standard input.\n"
28"\t-s\tprint nothing, only return an exit status\n";
29
30extern int tty_main(int argc, char **argv) {
31 char *tty;
32
33 if (argc > 1) {
34 if (argv[1][0] != '-' || argv[1][1] != 's') usage (tty_usage);
35 }
36 else {
37 tty = ttyname (0);
38 if (tty) puts (tty);
39 else puts ("not a tty");
40 }
41 exit (isatty (0) ? TRUE : FALSE);
42}