blob: b0a50ff61028ab89c57b99b69ef49b3f2aed49e4 [file] [log] [blame]
/* vi: set sw=4 ts=4: */
/*
* tty implementation for busybox
*
* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
/* BB_AUDIT SUSv3 compliant */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/tty.html */
#include "libbb.h"
int tty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int tty_main(int argc, char **argv)
{
const char *s;
USE_INCLUDE_SUSv2(int silent;) /* Note: No longer relevant in SUSv3. */
int retval;
xfunc_error_retval = 2; /* SUSv3 requires > 1 for error. */
USE_INCLUDE_SUSv2(silent = getopt32(argv, "s");)
/* gnu tty outputs a warning that it is ignoring all args. */
bb_warn_ignoring_args(argc - optind);
retval = 0;
s = ttyname(0);
if (s == NULL) {
/* According to SUSv3, ttyname can on fail with EBADF or ENOTTY.
* We know the file descriptor is good, so failure means not a tty. */
s = "not a tty";
retval = 1;
}
USE_INCLUDE_SUSv2(if (!silent) puts(s);)
SKIP_INCLUDE_SUSv2(puts(s);)
fflush_stdout_and_exit(retval);
}