xref: /third_party/toybox/toys/posix/tty.c (revision 0f66f451)
1/* tty.c - Show stdin's terminal name
2 *
3 * Copyright 2011 Rob Landley <rob@landley.net>
4 *
5 * See http://opengroup.org/onlinepubs/9699919799/utilities/tty.html
6
7USE_TTY(NEWTOY(tty, "s", TOYFLAG_USR|TOYFLAG_BIN))
8
9config TTY
10  bool "tty"
11  default y
12  help
13    usage: tty [-s]
14
15    Show filename of terminal connected to stdin.
16
17    Prints "not a tty" and exits with nonzero status if no terminal
18    is connected to stdin.
19
20    -s	Silent, exit code only
21*/
22
23#include "toys.h"
24
25void tty_main(void)
26{
27  char *tty = ttyname(0);
28
29  if (!toys.optflags) puts(tty ? tty : "not a tty");
30
31  toys.exitval = !tty;
32}
33