/* vi: set sw=4 ts=4: */
/*
- * Mini tty implementation for busybox
+ * tty implementation for busybox
*
- * Copyright (C) 2000 Edward Betts <edward@debian.org>.
+ * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.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
*
*/
-#include "internal.h"
-#include <stdio.h>
-#include <sys/types.h>
+/* BB_AUDIT SUSv3 compliant */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/tty.html */
-static const char tty_usage[] = "tty\n"
-#ifndef BB_FEATURE_TRIVIAL_HELP
- "\nPrint the file name of the terminal connected to standard input.\n\n"
- "Options:\n"
- "\t-s\tprint nothing, only return an exit status\n"
-#endif
- ;
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "busybox.h"
-extern int tty_main(int argc, char **argv)
+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");
+ const char *s;
+ int silent; /* Note: No longer relevant in SUSv3. */
+ int retval;
+
+ bb_default_error_retval = 2; /* SUSv3 requires > 1 for error. */
+
+ silent = bb_getopt_ulflags(argc, argv, "s");
+
+ /* 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;
}
- exit(isatty(0) ? TRUE : FALSE);
+
+ if (!silent) {
+ puts(s);
+ }
+
+ bb_fflush_stdout_and_exit(retval);
}