1 files changed, 44 insertions, 0 deletions
diff --git a/coreutils/tty.c b/coreutils/tty.c
new file mode 100644
index 0000000..e832894
--- /dev/null
+++ b/coreutils/tty.c
@@ -0,0 +1,44 @@
+/* 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 SKIP_INCLUDE_SUSv2(UNUSED_PARAM))
+{
+	const char *s;
+	USE_INCLUDE_SUSv2(int silent;)	/* Note: No longer relevant in SUSv3. */
+	int retval;
+
+	xfunc_error_retval = 2;	/* SUSv3 requires > 1 for error. */
+
+	USE_INCLUDE_SUSv2(silent = getopt32(argv, "s");)
+	USE_INCLUDE_SUSv2(argc -= optind;)
+	SKIP_INCLUDE_SUSv2(argc -= 1;)
+
+	/* gnu tty outputs a warning that it is ignoring all args. */
+	bb_warn_ignoring_args(argc);
+
+	retval = 0;
+
+	s = 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;
+	}
+	USE_INCLUDE_SUSv2(if (!silent) puts(s);)
+	SKIP_INCLUDE_SUSv2(puts(s);)
+
+	fflush_stdout_and_exit(retval);
+}