Implement ttyname() in case /dev/tty is not available

Close #1266
Close #447

src/tui/light.go

@@ -32,6 +32,12 @@ var offsetRegexp *regexp.Regexp = regexp.MustCompile("\x1b\\[([0-9]+);([0-9]+)R"
 func openTtyIn() *os.File {
 	in, err := os.OpenFile(consoleDevice, syscall.O_RDONLY, 0)
 	if err != nil {
+		tty := ttyname()
+		if len(tty) > 0 {
+			if in, err := os.OpenFile(tty, syscall.O_RDONLY, 0); err == nil {
+				return in
+			}
+		}
 		fmt.Fprintln(os.Stderr, "Failed to open "+consoleDevice)
 		os.Exit(2)
 	}