busybox/coreutils/tty.c
Denis Vlasenko 5e34ff29bc *: mass renaming of USE_XXXX to IF_XXXX
and SKIP_XXXX to IF_NOT_XXXX - the second one was especially
badly named. It was not skipping anything!
2009-04-21 11:09:40 +00:00

45 lines
1.2 KiB
C

/* 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 IF_NOT_INCLUDE_SUSv2(UNUSED_PARAM))
{
const char *s;
IF_INCLUDE_SUSv2(int silent;) /* Note: No longer relevant in SUSv3. */
int retval;
xfunc_error_retval = 2; /* SUSv3 requires > 1 for error. */
IF_INCLUDE_SUSv2(silent = getopt32(argv, "s");)
IF_INCLUDE_SUSv2(argc -= optind;)
IF_NOT_INCLUDE_SUSv2(argc -= 1;)
/* gnu tty outputs a warning that it is ignoring all args. */
bb_warn_ignoring_args(argc);
retval = 0;
s = xmalloc_ttyname(0);
if (s == NULL) {
/* According to SUSv3, ttyname can fail with EBADF or ENOTTY.
* We know the file descriptor is good, so failure means not a tty. */
s = "not a tty";
retval = 1;
}
IF_INCLUDE_SUSv2(if (!silent) puts(s);)
IF_NOT_INCLUDE_SUSv2(puts(s);)
fflush_stdout_and_exit(retval);
}