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 SUSv4 compliant */
11 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/tty.html */
15 int tty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
16 int tty_main(int argc, char **argv IF_NOT_INCLUDE_SUSv2(UNUSED_PARAM))
19 IF_INCLUDE_SUSv2(int silent;) /* Note: No longer relevant in SUSv3. */
22 xfunc_error_retval = 2; /* SUSv3 requires > 1 for error. */
24 IF_INCLUDE_SUSv2(silent = getopt32(argv, "s");)
25 IF_INCLUDE_SUSv2(argc -= optind;)
26 IF_NOT_INCLUDE_SUSv2(argc -= 1;)
28 /* gnu tty outputs a warning that it is ignoring all args. */
29 bb_warn_ignoring_args(argc);
31 retval = EXIT_SUCCESS;
33 s = xmalloc_ttyname(STDIN_FILENO);
35 /* According to SUSv3, ttyname can fail with EBADF or ENOTTY.
36 * We know the file descriptor is good, so failure means not a tty. */
38 retval = EXIT_FAILURE;
40 IF_INCLUDE_SUSv2(if (!silent) puts(s);)
41 IF_NOT_INCLUDE_SUSv2(puts(s);)
43 fflush_stdout_and_exit(retval);