@ ls works phew

tools/cmd/at/main.go

@@ -66,8 +66,22 @@ func get_pubkey(encoded_key string) (encryption_version string, pubkey []byte, e
 	return
 }
 
+func wrap_in_escape_code(data []byte) []byte {
+	const prefix = "\x1bP@kitty-cmd"
+	const suffix = "\x1b\\"
+	ans := make([]byte, len(prefix)+len(data)+len(suffix))
+	n := copy(ans, []byte(prefix))
+	n += copy(ans[n:], data)
+	copy(ans[n:], []byte(suffix))
+	return ans
+}
+
 func simple_serializer(rc *utils.RemoteControlCmd) (ans []byte, err error) {
 	ans, err = json.Marshal(rc)
+	if err != nil {
+		return
+	}
+	ans = wrap_in_escape_code(ans)
 	return
 }
 
@@ -84,7 +98,14 @@ func create_serializer(password string, encoded_pubkey string, io_data *rc_io_da
 		}
 		io_data.serializer = func(rc *utils.RemoteControlCmd) (ans []byte, err error) {
 			ec, err := crypto.Encrypt_cmd(rc, global_options.password, pubkey, encryption_version)
+			if err != nil {
+				return
+			}
 			ans, err = json.Marshal(ec)
+			if err != nil {
+				return
+			}
+			ans = wrap_in_escape_code(ans)
 			return
 		}
 		if io_data.timeout < 120*time.Second {
@@ -159,6 +180,14 @@ func (self *rc_io_data) next_chunk(limit_size bool) (chunk []byte, err error) {
 	return
 }
 
+func single_rc_sender(rc *utils.RemoteControlCmd, serializer serializer_func) ([]byte, error) {
+	if rc.SingleSent() {
+		return make([]byte, 0), nil
+	}
+	rc.SetSingleSent()
+	return serializer(rc)
+}
+
 func get_response(do_io func(io_data *rc_io_data) ([]byte, error), io_data *rc_io_data) (ans *Response, err error) {
 	serialized_response, err := do_io(io_data)
 	if err != nil {
@@ -166,9 +195,7 @@ func get_response(do_io func(io_data *rc_io_data) ([]byte, error), io_data *rc_i
 			io_data.rc.Payload = nil
 			io_data.rc.CancelAsync = true
 			io_data.rc.NoResponse = true
-			io_data.next_block = func(rc *utils.RemoteControlCmd, serializer serializer_func) ([]byte, error) {
-				return serializer(rc)
-			}
+			io_data.next_block = single_rc_sender
 			_, err = do_io(io_data)
 		}
 		return
@@ -252,6 +279,10 @@ func get_password(password string, password_file string, password_env string, us
 			q, err = os.ReadFile(password_file)
 			if err == nil {
 				ans = strings.TrimRight(string(q), " \n\t")
+			} else {
+				if errors.Is(err, os.ErrNotExist) {
+					err = nil
+				}
 			}
 		}
 		if err != nil {