kitty/docs/remote-control.rst

Control kitty from scripts
----------------------------

.. highlight:: sh

|kitty| can be controlled from scripts or the shell prompt. You can open new
windows, send arbitrary text input to any window, change the title of windows
and tabs, etc.

Let's walk through a few examples of controlling |kitty|.


Tutorial
------------

Start by running |kitty| as::

    kitty -o allow_remote_control=yes -o enabled_layouts=tall

In order for control to work, :opt:`allow_remote_control` must be enabled in
:file:`kitty.conf`. Here we turn it on explicitly at the command line.

Now, in the new |kitty| window, enter the command::

    kitty @ launch --title Output --keep-focus cat

This will open a new window, running the :program:`cat` program that will appear
next to the current window.

Let's send some text to this new window::

    kitty @ send-text --match cmdline:cat Hello, World

This will make ``Hello, World`` show up in the window running the :program:`cat`
program. The :option:`kitty @ send-text --match` option is very powerful, it
allows selecting windows by their titles, the command line of the program
running in the window, the working directory of the program running in the
window, etc. See :ref:`kitty @ send-text --help <at_send-text>` for details.

More usefully, you can pipe the output of a command running in one window to
another window, for example::

    ls | kitty @ send-text --match title:^Output --stdin

This will show the output of :program:`ls` in the output window instead of the
current window. You can use this technique to, for example, show the output of
running :program:`make` in your editor in a different window. The possibilities
are endless.

You can even have things you type show up in a different window. Run::

    kitty @ send-text --match title:^Output --stdin

And type some text, it will show up in the output window, instead of the current
window. Type :kbd:`Ctrl+D` when you are ready to stop.

Now, let's open a new tab::

   kitty @ launch --type=tab --tab-title "My Tab" --keep-focus bash

This will open a new tab running the bash shell with the title "My Tab".
We can change the title of the tab to "New Title" with::

   kitty @ set-tab-title --match title:^My New Title

Let's change the title of the current tab::

   kitty @ set-tab-title Master Tab

Now lets switch to the newly opened tab::

   kitty @ focus-tab --match title:^New

Similarly, to focus the previously opened output window (which will also switch
back to the old tab, automatically)::

   kitty @ focus-window --match title:^Output

You can get a listing of available tabs and windows, by running::

   kitty @ ls

This outputs a tree of data in JSON format. The top level of the tree is all
:term:`OS windows <os_window>`. Each OS window has an id and a list of
:term:`tabs <tab>`. Each tab has its own id, a title and a list of :term:`kitty
windows <window>`. Each window has an id, title, current working directory,
process id (PID) and command-line of the process running in the window. You can
use this information with :option:`kitty @ focus-window --match` to control
individual windows.

As you can see, it is very easy to control |kitty| using the ``kitty @``
messaging system. This tutorial touches only the surface of what is possible.
See ``kitty @ --help`` for more details.

Note that in the example's above, ``kitty @`` messaging works only when run
inside a |kitty| window, not anywhere. But, within a |kitty| window it even
works over SSH. If you want to control |kitty| from programs/scripts not running
inside a |kitty| window, you have to implement a couple of extra steps. First
start |kitty| as::

    kitty -o allow_remote_control=yes --listen-on unix:/tmp/mykitty

The :option:`kitty --listen-on` option tells |kitty| to listen for control
messages at the specified UNIX-domain socket. See ``kitty --help`` for details.
Now you can control this instance of |kitty| using the :option:`kitty @ --to`
command line argument to ``kitty @``. For example::

    kitty @ --to unix:/tmp/mykitty ls


Note that if all you want to do is run a single |kitty| "daemon" and have
subsequent |kitty| invocations appear as new top-level windows, you can use the
simpler :option:`kitty --single-instance` option, see ``kitty --help`` for that.


The builtin kitty shell
--------------------------

You can explore the |kitty| command language more easily using the builtin
|kitty| shell. Run ``kitty @`` with no arguments and you will be dropped into
the |kitty| shell with completion for |kitty| command names and options.

You can even open the |kitty| shell inside a running |kitty| using a simple
keyboard shortcut (:sc:`kitty_shell` by default).

.. note:: This has the added advantage that you don't need to use
   :opt:`allow_remote_control` to make it work.


Allowing only some windows to control kitty
----------------------------------------------

If you do not want to allow all programs running in |kitty| to control it, you
can selectively enable remote control for only some |kitty| windows. Simply
create a shortcut such as::

    map ctrl+k launch --allow-remote-control some_program

Then programs running in windows created with that shortcut can use ``kitty @``
to control kitty. Note that any program with the right level of permissions can
still write to the pipes of any other program on the same computer and therefore
can control |kitty|. It can, however, be useful to block programs running on
other computers (for example, over SSH) or as other users.

.. note:: You don't need :opt:`allow_remote_control` to make this work as it is
   limited to only programs running in that specific window. Be careful with
   what programs you run in such windows, since they can effectively control
   kitty, as if you were running with :opt:`allow_remote_control` turned on.


.. _rc_mapping:

Mapping key presses to remote control commands
--------------------------------------------------

If you wish to trigger a remote control command easily with just a keypress,
you can map it in :file:`kitty.conf`. For example::

    map f1 remote_control set-spacing margin=30

Then pressing the :kbd:`F1` key will set the active window margins to
:code:`30`. The syntax for what follows :ac:`remote_control` is exactly the same
as the syntax for what follows :code:`kitty @` above.

.. note:: You do not need :opt:`allow_remote_control` to use these mappings,
   as they are not actual remote programs, but are simply a way to resuse the
   remote control infrastructure via keybings.


Broadcasting what you type to all kitty windows
--------------------------------------------------

As a simple illustration of the power of remote control, lets
have what we type sent to all open kitty windows. To do that define the
following mapping in :file:`kitty.conf`::

    map f1 launch --allow-remote-control kitty +kitten broadcast

Now press :kbd:`F1` and start typing, what you type will be sent to all windows,
live, as you type it.


The remote control protocol
-----------------------------------------------

If you wish to develop your own client to talk to |kitty|, you can use the
:doc:`remote control protocol specification <rc_protocol>`.


.. _search_syntax:

Matching windows and tabs
----------------------------

Many remote control operations operate on windows or tabs. To select these, the
:code:`--match` option is often used. This allows matching using various
sophisticated criteria such as title, ids, cmdlines, etc. These criteria are
expressions of the form :code:`field:query`. Where :italic:`field` is the field
against which to match and :italic:`query` is the expression to match. They can
be further combined using Boolean operators, best illustrated with some
examples::

    title:"My special window" or id:43
    title:bash and env:USER=kovid
    not id:1
    (id:2 or id:3) and title:something

.. toctree::
   :hidden:

   rc_protocol

.. include:: generated/cli-kitty-at.rst