Implement tty command.

diff --git a/toys/tty.c b/toys/tty.c
new file mode 100644 (file)
index 0000000..661e919
--- /dev/null
+++ b/toys/tty.c
@@ -0,0 +1,32 @@
+/* vi: set sw=4 ts=4:
+ *
+ * tty.c - Show stdin's terminal name
+ *
+ * Copyright 2011 Rob Landley <rob@landley.net>
+ *
+ * See http://opengroup.org/onlinepubs/9699919799/utilities/tty.html
+
+USE_TTY(NEWTOY(tty, "s", TOYFLAG_USR|TOYFLAG_BIN))
+
+config TTY
+       bool "tty"
+       default y
+       help
+         Show filename of terminal connected to stdin.
+
+         Prints "not a tty" and exits with nonzero status if no terminal
+         is connected to stdin.
+
+         -s    silent mode
+*/
+
+#include "toys.h"
+
+void tty_main(void)
+{
+       char *tty = ttyname(0);
+
+       if (!toys.optflags) puts(tty ? tty : "not a tty");
+
+       toys.exitval = !tty;
+}