/* vi: set sw=4 ts=4: */
/*
- * Mini tty implementation for busybox
+ * 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
+ * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
*
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//config:config TTY
+//config: bool "tty (3.3 kb)"
+//config: default y
+//config: help
+//config: tty is used to print the name of the current terminal to
+//config: standard output.
+
+//applet:IF_TTY(APPLET_NOFORK(tty, tty, BB_DIR_USR_BIN, BB_SUID_DROP, tty))
+
+//kbuild:lib-$(CONFIG_TTY) += tty.o
+
+/* BB_AUDIT SUSv4 compliant */
+/* http://www.opengroup.org/onlinepubs/9699919799/utilities/tty.html */
-#include "internal.h"
-#include <stdio.h>
-#include <sys/types.h>
+//usage:#define tty_trivial_usage
+//usage: ""
+//usage:#define tty_full_usage "\n\n"
+//usage: "Print file name of stdin's terminal"
+//usage: IF_INCLUDE_SUSv2( "\n"
+//usage: "\n -s Print nothing, only return exit status"
+//usage: )
+//usage:
+//usage:#define tty_example_usage
+//usage: "$ tty\n"
+//usage: "/dev/tty2\n"
-static const char tty_usage[] = "tty\n\n"
- "Print the file name of the terminal connected to standard input.\n\n"
- "Options:\n"
- "\t-s\tprint nothing, only return an exit status\n";
+#include "libbb.h"
-extern int tty_main(int argc, char **argv)
+int tty_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int tty_main(int argc UNUSED_PARAM, 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");
+ 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(argv += optind;)
+ IF_NOT_INCLUDE_SUSv2(argv += 1;)
+
+ /* gnu tty outputs a warning that it is ignoring all args. */
+ bb_warn_ignoring_args(argv[0]);
+
+ retval = EXIT_SUCCESS;
+
+ s = xmalloc_ttyname(STDIN_FILENO);
+ 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 = EXIT_FAILURE;
}
- exit(isatty(0) ? TRUE : FALSE);
+ IF_INCLUDE_SUSv2(if (!silent) puts(s);)
+ IF_NOT_INCLUDE_SUSv2(puts(s);)
+
+ fflush_stdout_and_exit(retval);
}