busybox/coreutils/tty.c

46 lines
1015 B
C
Raw Normal View History

/* vi: set sw=4 ts=4: */
/*
2003-03-19 14:43:01 +05:30
* tty implementation for busybox
*
2003-03-19 14:43:01 +05:30
* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
2003-03-19 14:43:01 +05:30
/* BB_AUDIT SUSv3 compliant */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/tty.html */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "busybox.h"
int tty_main(int argc, char **argv)
{
2003-03-19 14:43:01 +05:30
const char *s;
int silent; /* Note: No longer relevant in SUSv3. */
int retval;
xfunc_error_retval = 2; /* SUSv3 requires > 1 for error. */
2003-03-19 14:43:01 +05:30
silent = getopt32(argc, argv, "s");
2003-03-19 14:43:01 +05:30
/* gnu tty outputs a warning that it is ignoring all args. */
bb_warn_ignoring_args(argc - optind);
retval = 0;
if ((s = ttyname(0)) == 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;
}
if (!silent) {
puts(s);
}
2003-03-19 14:43:01 +05:30
bb_fflush_stdout_and_exit(retval);
}