1 /* vi: set sw=4 ts=4: */
3 * tty implementation for busybox
5 * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
10 /* BB_AUDIT SUSv3 compliant */
11 /* http://www.opengroup.org/onlinepubs/007904975/utilities/tty.html */
18 int tty_main(int argc, char **argv);
19 int tty_main(int argc, char **argv)
22 USE_INCLUDE_SUSv2(int silent;) /* Note: No longer relevant in SUSv3. */
25 xfunc_error_retval = 2; /* SUSv3 requires > 1 for error. */
27 USE_INCLUDE_SUSv2(silent = getopt32(argc, argv, "s");)
29 /* gnu tty outputs a warning that it is ignoring all args. */
30 bb_warn_ignoring_args(argc - optind);
34 if ((s = ttyname(0)) == NULL) {
35 /* According to SUSv3, ttyname can on fail with EBADF or ENOTTY.
36 * We know the file descriptor is good, so failure means not a tty. */
40 USE_INCLUDE_SUSv2(if (!silent) puts(s);)
41 SKIP_INCLUDE_SUSv2(puts(s);)
43 fflush_stdout_and_exit(retval);