Allow rc commands to control the exit code

tools/cmd/at/main.go

@@ -247,6 +247,16 @@ func get_response(do_io func(io_data *rc_io_data) ([]byte, error), io_data *rc_i
 	return
 }
 
+var running_shell = false
+
+type exit_error struct {
+	exit_code int
+}
+
+func (m *exit_error) Error() string {
+	return fmt.Sprintf("Subprocess exit with code: %d", m.exit_code)
+}
+
 func send_rc_command(io_data *rc_io_data) (err error) {
 	err = setup_global_options(io_data.cmd)
 	if err != nil {

tools/cmd/at/shell.go

@@ -203,6 +203,7 @@ func shell_main(cmd *cli.Command, args []string) (int, error) {
 	if err != nil {
 		return 1, err
 	}
+	running_shell = true
 	formatter = markup.New(true)
 	fmt.Println("Welcome to the kitty shell!")
 	fmt.Println("Use", formatter.Green("help"), "for assistance or", formatter.Green("exit"), "to quit.")

tools/cmd/at/template.go

@@ -90,6 +90,9 @@ func run_CMD_NAME(cmd *cli.Command, args []string) (return_code int, err error)
 	}
 
 	err = send_rc_command(&io_data)
+	if ee, ok := err.(*exit_error); ok && !running_shell {
+		return ee.exit_code, nil
+	}
 	return
 }