kitten @ run: A new remote control command to run a process on the machine kitty is running on and get its output

Fixes #7429

tools/cmd/at/run.go

@@ -0,0 +1,80 @@
+package at
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"kitty/tools/tty"
+)
+
+var _ = fmt.Print
+
+type run_response_data struct {
+	Stdout      string `json:"stdout"`
+	Stderr      string `json:"stderr"`
+	Exit_code   int    `json:"exit_code"`
+	Exit_status int    `json:"exit_status"`
+}
+
+func run_handle_response(data []byte) error {
+	var r run_response_data
+	if err := json.Unmarshal(data, &r); err != nil {
+		return err
+	}
+	if stdout, err := base64.StdEncoding.DecodeString(r.Stdout); err == nil {
+		_, _ = os.Stdout.Write(stdout)
+	} else {
+		return err
+	}
+	if stderr, err := base64.StdEncoding.DecodeString(r.Stderr); err == nil {
+		_, _ = os.Stderr.Write(stderr)
+	} else {
+		return err
+	}
+	if r.Exit_code != 0 {
+		return &exit_error{r.Exit_code}
+	}
+	return nil
+}
+
+func read_run_data(io_data *rc_io_data, args []string, payload *run_json_type) (func(io_data *rc_io_data) (bool, error), error) {
+	is_first_call := true
+	is_tty := tty.IsTerminal(os.Stdin.Fd())
+	buf := make([]byte, 4096)
+	cmdline := make([]escaped_string, len(args))
+	for i, s := range args {
+		cmdline[i] = escaped_string(s)
+	}
+	payload.Cmdline = cmdline
+	io_data.handle_response = run_handle_response
+
+	return func(io_data *rc_io_data) (bool, error) {
+		if is_first_call {
+			is_first_call = false
+		} else {
+			io_data.rc.Stream = false
+		}
+		buf = buf[:cap(buf)]
+		var n int
+		var err error
+		if is_tty {
+			buf = buf[:0]
+			err = io.EOF
+		} else {
+			n, err = os.Stdin.Read(buf)
+			if err != nil && err != io.EOF {
+				return false, err
+			}
+			buf = buf[:n]
+		}
+		set_payload_data(io_data, base64.StdEncoding.EncodeToString(buf))
+		if err == io.EOF {
+			return true, nil
+		}
+		return false, nil
+	}, nil
+
+}