busybox/coreutils/tty.c

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/* vi: set sw=4 ts=4: */
/*
* Mini tty implementation for busybox
*
* Copyright (C) 2000 Edward Betts <edward@debian.org>.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include "internal.h"
#include <stdio.h>
#include <sys/types.h>
static const char tty_usage[] = "tty\n\n"
"Print the file name of the terminal connected to standard input.\n"
"\t-s\tprint nothing, only return an exit status\n";
extern int tty_main(int argc, char **argv)
{
char *tty;
if (argc > 1) {
if (argv[1][0] != '-' || argv[1][1] != 's')
usage(tty_usage);
} else {
tty = ttyname(0);
if (tty)
puts(tty);
else
puts("not a tty");
}
exit(isatty(0) ? TRUE : FALSE);
}