:orphan:

Glossary
=========

.. glossary::

   os_window
     kitty has two kinds of windows. Operating System windows, refered to as :term:`OS
     Window <os_window>`, and *kitty windows*. An OS Window consists of one or more kitty
     :term:`tabs <tab>`. Each tab in turn consists of one or more *kitty
     windows* organized in a :term:`layout`.

   tab
     A *tab* refers to a group of :term:`kitty windows <window>`, organized in
     a :term:`layout`. Every :term:`OS Window <os_window>` contains one or more tabs.

   layout
     A *layout* is a system of organizing :term:`kitty windows <window>` in
     groups inside a tab. The layout automatically maintains the size and
     position of the windows, think of a layout as a tiling window manager for
     the terminal. See :doc:`layouts` for details.

   window
     kitty has two kinds of windows. Operating System windows, refered to as :term:`OS
     Window <os_window>`, and *kitty windows*. An OS Window consists of one or more kitty
     :term:`tabs <tab>`. Each tab in turn consists of one or more *kitty
     windows* organized in a :term:`layout`.

   overlay
      An *overlay window* is a :term:`kitty window <window>` that is placed on
      top of an existing kitty window, entirely covering it. Overlays are used
      throught kitty, for example, to display the :ref:`the scrollback buffer <scrollback>`,
      to display :doc:`hints </kittens/hints>`, for :doc:`unicode input
      </kittens/unicode-input>` etc.

   hyperlinks
      Terminals can have hyperlinks, just like the internet. In kitty you can
      :doc:`control exactly what happens <open_actions>` when clicking on a
      hyperlink, based on the type of link and its URL.

.. _env_vars:

Environment variables
------------------------

Variables that influence kitty behavior

.. envvar:: KITTY_CONFIG_DIRECTORY

   Controls where kitty looks for :file:`kitty.conf` and other configuration
   files. Defaults to :file:`~/.config/kitty`. For full details of the config
   directory lookup mechanism see, :option:`kitty --config`.


.. envvar:: VISUAL

   The terminal editor (such as ``vi`` or ``nano``) kitty uses, when, for
   instance, opening :file:`kitty.conf` in response to :sc:`edit_config_file`.


.. envvar:: EDITOR

   Same as :envvar:`VISUAL`. Used if :envvar:`VISUAL` is not set.


Variables that kitty sets when running child programs

.. envvar:: LANG

   This is set only on macOS, and only if the country and language from the
   macOS user settings form a valid locale.


.. envvar:: KITTY_WINDOW_ID

   An integer that is the id for the kitty :term:`window` the program is running in.
   Can be used with the :doc:`kitty remote control facility <remote-control>`.


.. envvar:: KITTY_PID

   An integer that is the process id for the kitty process in which the program
   is running. Allows programs to tell kitty to reload its config by sending it
   the SIGUSR1 signal.


.. envvar:: WINDOWID

   The id for the :term:`OS Window <os_window>` the program is running in. Only available
   on platforms that have ids for their windows, such as X11 and macOS.


.. envvar:: TERM

   The name of the terminal, defaults to ``xterm-kitty``. See :opt:`term`.


.. envvar:: TERMINFO

   Path to a directory containing the kitty terminfo database.


.. envvar:: COLORTERM

   Set to the value ``truecolor`` to indicate that kitty supports 16 million
   colors.


.. envvar:: KITTY_LISTEN_ON

   Set when the :doc:`remote control <remote-control>` facility is enabled and
   the a socket is used for control via :option:`kitty --listen-on` or :opt:`listen_on`.
   Contains the path to the socket. Avoids needs to use :option:`kitty @ --to` when
   issuing remote control commands.


.. envvar:: KITTY_PIPE_DATA

   Set to data describing the layout of the screen when running child
   programs using :option:`launch --stdin-source` with the contents of the
   screen/scrollback piped to them.


.. envvar:: KITTY_CHILD_CMDLINE

   Set to the command line of the child process running in the kitty
   window when calling the notification callback program on terminal bell, see
   :opt:`command_on_bell`.


.. envvar:: KITTY_COMMON_OPTS

   Set with the values of some common kitty options when running
   kittens, so kittens can use them without needing to load kitty.conf.
