content: 
  Termonad
  =========
  
  [![CI](https://github.com/cdepillabout/termonad/actions/workflows/ci.yml/badge.svg)](https://github.com/cdepillabout/termonad/actions/workflows/ci.yml)
  [![Hackage](https://img.shields.io/hackage/v/termonad.svg)](https://hackage.haskell.org/package/termonad)
  [![Stackage LTS](http://stackage.org/package/termonad/badge/lts)](http://stackage.org/lts/package/termonad)
  [![Stackage Nightly](http://stackage.org/package/termonad/badge/nightly)](http://stackage.org/nightly/package/termonad)
  [![BSD3 license](https://img.shields.io/badge/license-BSD3-blue.svg)](./LICENSE)
  [![Join the chat at https://gitter.im/termonad/Lobby](https://badges.gitter.im/termonad/Lobby.svg)](https://gitter.im/termonad/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
  
  Termonad is a terminal emulator configurable in Haskell.  It is extremely
  customizable and provides hooks to modify the default behavior.  It can be
  thought of as the "XMonad" of terminal emulators.
  
  ![image of Termonad](./img/termonad.png)
  
  Termonad was
  [featured on an episode](https://www.youtube.com/watch?v=TLNr_gBv5HY) of
  [DistroTube](https://www.youtube.com/channel/UCVls1GmFKf6WlTraIb_IaJg).
  This video gives a short overview of Termonad.
  
  <!-- markdown-toc start - Don't edit this section. Run M-x markdown-toc-refresh-toc -->
  **Table of Contents**
  
  - [Termonad](#termonad)
    - [Installation](#installation)
      - [Arch Linux](#arch-linux)
      - [Ubuntu / Debian](#ubuntu--debian)
      - [Nix](#nix)
      - [Mac OS X](#mac-os-x)
        - [Installing with just `stack`](#installing-with-just-stack)
        - [Installing with just `nix`](#installing-with-just-nix)
        - [Installing with `stack` using `nix`](#installing-with-stack-using-nix)
      - [Windows](#windows)
    - [How to use Termonad](#how-to-use-termonad)
      - [Default Key Bindings](#default-key-bindings)
      - [Configuring Termonad](#configuring-termonad)
      - [Compiling Local Settings](#compiling-local-settings)
        - [Running with `stack`](#running-with-stack)
        - [Running with `nix`](#running-with-nix)
    - [Goals](#goals)
    - [Where to get help](#where-to-get-help)
    - [Contributions](#contributions)
    - [Maintainers](#maintainers)
  
  <!-- markdown-toc end -->
  
  ## Installation
  
  Termonad can be installed on any system as long as the necessary GTK libraries
  are available.  The following are instructions for installing Termonad on a few
  different distributions and systems.  If the given steps don't work for you, or
  you want to add instructions for an additional system, please send a pull
  request.
  
  The following steps use the
  [`stack`](https://docs.haskellstack.org/en/stable/README/) build tool to build
  Termonad, but [`cabal`](https://www.haskell.org/cabal/) can be used as well. Steps for
  installing `stack` can be found on
  [this page](https://docs.haskellstack.org/en/stable/install_and_upgrade/).
  
  
  ### Arch Linux
  
  First, you must install the required Gnome/GTK system libraries:
  
  ```sh
  $ pacman -S vte3 gobject-introspection
  ```
  
  In order to install Termonad, clone this repository and run `stack install`.
  This will install the `termonad` binary to `~/.local/bin/`:
  
  ```sh
  $ git clone https://github.com/cdepillabout/termonad
  $ cd termonad/
  $ stack install
  ```
  
  Note that Termonad depends on the [`haskell-gi`](https://github.com/haskell-gi/haskell-gi) family of Haskell libraries.  `haskell-gi` contains Haskell wrappers for for Gnome/GTK system libraries.  It uses the [GObject Introspection](https://gi.readthedocs.io/en/latest/) functionality from the Gnome libraries.
  
  One problem that Arch users often run into is that their system Gnome/GTK libraries are newer than what the `haskell-gi` dependencies from Stackage support.  If you run into this problem, there are a couple things you can try:
  
  - Manually switch to a newer Stackage resolver (probably Stackage Nightly).  Newer Stackage resolvers often have newer versions of the `haskell-gi` libraries.  Newer versions of the `haskell-gi` libraries are more likely to support your newer system Gnome/GTK libraries.  If you get something working like this, please open a PR.
  - Use `cabal` for building Termonad instead of `stack`.  Make sure `cabal`'s constraint solver picks the latest versions of the `haskell-gi` libraries on Hackage.
  - Use Nix for installing Termonad.
  
  My suggestion is to use Nix, since it is highly likely to "just work" (because with Nix, _all_ libraries are pinned to known working versions, even system libraries).
  
  ### Ubuntu / Debian
  
  Termonad can be installed through `apt` on Debian and Ubuntu:
  
  ```console
  $ sudo apt install termonad libghc-termonad-dev
  ```
  
  Note that the `libghc-termonad-dev` package is necessary if you want to be able
  to compile the Haskell-based settings file, `termonad.hs`.
  
  #### Compiling from source on Ubuntu / Debian
  
  First, you must install the required Gnome/GTK system libraries:
  
  ```sh
  $ apt-get install gobject-introspection libgirepository1.0-dev libgtk-3-dev libvte-2.91-dev libpcre2-dev
  ```
  
  In order to install Termonad, clone this repository and run `stack install`.
  This will install the `termonad` binary to `~/.local/bin/`:
  
  ```sh
  $ git clone https://github.com/cdepillabout/termonad
  $ cd termonad/
  $ stack install
  ```
  
  ### Nix
  
  If you have `nix` installed, you should be able to use it to obtain Termonad.
  This means that it will work on NixOS, or with `nix` on another distro.  There
  are three different ways to use `nix` to get Termonad:
  
  1.  Get Termonad from Nixpkgs.  Termonad is provided as a top-level `termonad`
      attribute in Nixpkgs.
  
      For instance, run a `nix-shell` with Termonad:
  
      ```console
      $ nix-shell -p termonad
      $ termonad   # run termonad within the nix-shell
      ```
  
      You can also install `termonad` with tools like `nix-env` or home-manager.
      If you're using NixOS, you can add `termonad` to your
      `environment.systemPackages` list.
  
      Keep in mind that if you're using an old release of NixOS, you'll likely
      get an older version of Termonad.
  
  2.  Build Termonad using the code in this repository. The following commands
      clone this repo and build the `termonad` binary at `./result/bin/`:
  
      ```sh
      $ git clone https://github.com/cdepillabout/termonad
      $ cd termonad/
      $ nix-build
      ```
  
  3.  Build Termonad using `stack` with Nix-integration. The following commands
      install `stack` for your user, clone this repository, and install the
      `termonad` binary to `~/.local/bin/`:
  
      ```sh
      $ nix-env -i stack
      $ git clone https://github.com/cdepillabout/termonad
      $ cd termonad/
      $ stack --nix install
      ```
  
      (_edit_: Building with `stack` using Nix-integration does not currently work.
      See [#99](https://github.com/cdepillabout/termonad/issues/99).)
  
  ### Mac OS X
  
  Building and installing Termonad on Mac OS X should be possible with any of the following three methods:
  
  -   Install the required system libraries (like GTK and VTE) by hand, then use
      `stack` to build Termonad.
  
      This is probably the easiest method.  You don't have to understand anything
      about `nix`.  However, it is slightly annoying to have to install GTK and
      VTE by hand.
  
  -   Use `nix` to install both the required system libraries and Termonad itself.
  
      If you are a nix user and want an easy way to install Termonad, this
      is the recommended method.
  
  -   Use `nix` to install install the required system libraries, and `stack` to
      build Termonad.
  
      If you are a nix user, but want to use `stack` to actually do development
      on Termonad, using `stack` may be easier than using `cabal`.
  
  The following sections describe each method.
  
  #### Installing with just `stack`
  
  (*currently no instructions available.  please send a PR adding instructions if you get termonad to build using this method.*)
  
  #### Installing with just `nix`
  
  `nix` can be used to install Termonad with the following steps, assuming you
  have `nix` [installed](https://nixos.org/nix/download.html).  These commands
  clone this repository and build the `termonad` binary at `./result/bin/`:
  
  ```sh
  $ git clone https://github.com/cdepillabout/termonad
  $ cd termonad/
  $ nix-build
  ```
  
  #### Installing with `stack` using `nix`
  
  `stack` can be used in conjunction with `nix` to install Termonad.  `nix` will
  handle installing system dependencies (like GTK and VTE), while `stack` will
  handle compiling and installing Haskell packages.
  
  You must have `nix` [installed](https://nixos.org/nix/download.html).
  
  You will also need `stack` installed.  You can do that with the following command:
  
  ```sh
  $ nix-env -i stack
  ```
  
  After `stack` is installed, you will need to clone Termonad and build it:
  
  ```
  $ git clone https://github.com/cdepillabout/termonad
  $ cd termonad/
  $ stack --nix install
  ```
  
  This will install the `termonad` binary to `~/.local/bin/`.
  
  ### Windows
  
  To run Termonad on Windows, you'll need:
  
  * any X server app, for example **Vcxsrv**
  * any WSL, for example **Ubuntu**
  
  I'm using both Vcxsrv and Ubuntu WSL.
  
  Configure both Vcxsrv and WSL. For Vcxsrv go with default settings
  everywhere, it will be fine. Configure your WSL as you want (choose
  your name etc.). After you set up the user, you'll have to update your
  OS, run:
  
  ```console
  $ sudo apt-get update
  $ sudo apt-get upgrade -y
  $ sudo apt-get dist-upgrade -y
  $ sudo apt-get autoremove -y
  ```
  
  Configure the `DISPLAY` environment variable for the X server, and load the changes in bash:
  
  For WSL1:
  
  ```console
  $ echo "export DISPLAY=localhost:0.0" >> ~/.bashrc
  $ source ~/.bashrc
  ```
  
  For WSL2:
  
  ```console
  $ echo export DISPLAY=$(awk '/nameserver / {print $2; exit}' /etc/resolv.conf 2>/dev/null):0 >> ~/.bashrc
  $ echo export LIBGL_ALWAYS_INDIRECT=1 >> ~/.bashrc
  $ source ~/.bashrc
  ```
  
  If you're using WSL2, you have to create a separate **inbound rule** for TCP port 6000, to allow WSL access to the X server.
  If you're using mentioned earlier **Vcxsrv** you can enable public access for your X server by disabling Access Control on the Extra Settings.
  You can also use `-ac` flag in the Additional parameters for VcXsrv section.
  
  Your X server should now be configured.
  
  Execute following command to install the necessary GTK system libraries:
  
  ```console
  $ apt-get install gobject-introspection libgirepository1.0-dev libgtk-3-dev libvte-2.91-dev libpcre2-dev
  ```
  
  The required GTK system libraries should now be installed.
  
  Clone the Termonad repo:
  
  ```sh
  $ git clone https://github.com/cdepillabout/termonad
  $ cd termonad/
  $ stack build
  $ stack run
  ```
  After `stack run`, you should see a new window with your Termonad running.
  
  ## How to use Termonad
  
  Termonad is similar to XMonad. The above steps will install a `termonad` binary
  somewhere on your system. If you have installed Termonad using `stack`, the
  `termonad` binary will be in `~/.local/bin/`. If you have installed Termonad using
  your Linux distro, the `termonad` binary will likely be in `/usr/bin/`. This
  binary is a version of Termonad configured with default settings. You can try
  running it to get an idea of what Termonad is like:
  
  ```sh
  $ /usr/bin/termonad
  ```
  
  If you would like to configure Termonad with your own settings, first you will
  need to create a Haskell file called `~/.config/termonad/termonad.hs`. A following
  section gives an example configuration file.
  
  If this configuration file exists, when the `/usr/bin/termonad` binary
  launches, it will try to use GHC to compile the configuration file. If GHC
  is able to successfully compile the configuration file, a separate binary will
  be created called something like `~/.cache/termonad/termonad-linux-x86_64`.
  This binary file can be thought of as your own personal Termonad, configured
  with all your own settings.
  
  When you run `/usr/bin/termonad`, it will re-exec
  `~/.cache/termonad/termonad-linux-x86_64` if it exists.
  
  However, there is one difficulty with this setup. In order for the
  `/usr/bin/termonad` binary to be able to compile your
  `~/.config/termonad/termonad.hs` configuration file, Termonad needs to know
  where GHC is, as well as where all your Haskell packages live. This presents
  some difficulties that will be discussed in one of the following sections.
  
  ### Default Key Bindings
  
  Termonad provides the following default key bindings.
  
  | Key binding | Action |
  |------------|--------|
  | <kbd>Ctrl</kbd> <kbd>Shift</kbd> <kbd>t</kbd> | Open new tab. |
  | <kbd>Ctrl</kbd> <kbd>Shift</kbd> <kbd>w</kbd> | Close tab. |
  | <kbd>Ctrl</kbd> <kbd>Shift</kbd> <kbd>f</kbd> | Open Find dialog for searching for a regex. |
  | <kbd>Ctrl</kbd> <kbd>Shift</kbd> <kbd>p</kbd> | Find the regex **above** the current position. |
  | <kbd>Ctrl</kbd> <kbd>Shift</kbd> <kbd>i</kbd> | Find the regex **below** the current position. |
  | <kbd>Ctrl</kbd> <kbd>+</kbd> | Increase font size. |
  | <kbd>Ctrl</kbd> <kbd>-</kbd> | Decrease font size. |
  | <kbd>Ctrl</kbd> <kbd>PgUp</kbd> | Switch to previous tab. |
  | <kbd>Ctrl</kbd> <kbd>PgDown</kbd> | Switch to next tab. |
  | <kbd>Alt</kbd> <kbd>(number key)</kbd> | Switch to tab `number`.  For example, <kbd>Alt</kbd> <kbd>2</kbd> switches to tab 2. |
  
  ### Configuring Termonad
  
  Termonad has three different ways to be configured.
  
  1.  Pass arguments on the command line.  For instance, run
      `termonad --no-show-menu` to never show the `File` menubar.
  
      Arguments passed on the command line will normally override other
      configuration methods.
  
  2.  Use the built-in Preferences editor.  You can find this in
      the `Preferences` menu under `Edit` in the menubar.
  
      When opening Termonad for the first time, it will create a preferences file
      at `~/.config/termonad/termonad.yaml`.  When you change a setting in the
      Preferences editor, Termonad will update the setting in the preferences
      file.
  
      When running Termonad, it will load settings from the preferences file. Do
      not edit the preferences file by hand, because it will be overwritten when
      updating settings in the Preferences editor.
  
      This method is perfect for users who only want to make small changes to the
      Termonad settings, like the default font size.
  
  3.  Use a Haskell-based settings file, called `~/.config/termonad/termonad.hs` by default.
      This method allows you to make large, sweeping changes to Termonad.  This
      method is recommended for power users.
  
      The rest of this section explains the `~/.config/termonad/termonad.hs` file.
  
  **WARNING: If you have a `~/.config/termonad/termonad.hs` file, then all
  settings from `~/.config/termonad/termonad.yaml` will be ignored.  If you want
  to set *ANY* settings in `~/.config/termonad/termonad.hs`, then you must
  set *ALL* settings in `~/.config/termonad/termonad.hs`.  However, as stated above,
  CLI arguments will override settings in `~/.config/termonad/termonad.hs` by default.**
  
  The following is an example Termonad configuration file. You should save this to
  `~/.config/termonad/termonad.hs`. You can find more information on the available
  configuration options within the
  [`Termonad.Config`](https://hackage.haskell.org/package/termonad/docs/Termonad-Config.html)
  module.
  
  ```haskell
  {-# LANGUAGE OverloadedStrings #-}
  
  module Main where
  
  import Termonad
    ( FontConfig, FontSize(FontSizePoints), Option(Set)
    , ShowScrollbar(ShowScrollbarAlways), defaultConfigOptions, defaultFontConfig
    , defaultMain, defaultTMConfig, fontConfig, fontFamily, fontSize, options
    , showScrollbar
    )
  import Termonad.Config.Colour
    ( AlphaColour, ColourConfig, addColourExtension, createColour
    , createColourExtension, cursorBgColour, defaultColourConfig
    )
  
  -- | This sets the color of the cursor in the terminal.
  --
  -- This uses the "Data.Colour" module to define a dark-red color.
  -- There are many default colors defined in "Data.Colour.Names".
  cursBgColour :: AlphaColour Double
  cursBgColour = createColour 204 0 0
  
  -- | This sets the colors used for the terminal.  We only specify the background
  -- color of the cursor.
  colConf :: ColourConfig (AlphaColour Double)
  colConf =
    defaultColourConfig
      { cursorBgColour = Set cursBgColour
      }
  
  -- | This defines the font for the terminal.
  fontConf :: FontConfig
  fontConf =
    defaultFontConfig
      { fontFamily = "DejaVu Sans Mono"
      , fontSize = FontSizePoints 13
      }
  
  main :: IO ()
  main = do
    colExt <- createColourExtension colConf
    let termonadConf =
          defaultTMConfig
            { options =
                defaultConfigOptions
                  { fontConfig = fontConf
                    -- Make sure the scrollbar is always visible.
                  , showScrollbar = ShowScrollbarAlways
                  }
            }
          `addColourExtension` colExt
    defaultMain termonadConf
  ```
  
  There are other example configuration files in the
  [example-config/](./example-config) directory.
  
  If you want to test what all the colors look like, you may find it convenient
  to use the
  [`print-console-colors`](http://hackage.haskell.org/package/print-console-colors)
  package, which provides an executable called `print-console-colors` that prints
  all of the colors for your terminal.
  
  ### Compiling Local Settings
  
  If you launch Termonad by calling `/usr/bin/termonad`, it will try to
  compile the `~/.config/termonad/termonad.hs` file if it exists.  The problem is
  that `/usr/bin/termonad` needs to be able to see GHC and the required
  Haskell libraries to be able to compile `~/.config/termonad/termonad.hs`.
  
  There are a couple solutions to this problem, listed in the sections below.
  
  (These steps are definitely confusing. I would love to figure out a better
  way to do this.  Please submit an issue or PR if you have a good idea about
  how to fix this.)
  
  #### Running with `stack`
  
  If you originally compiled Termonad with `stack` and installed it to
  `~/.local/bin/termonad`, you can use `stack` to execute Termonad.  First, you
  must change to the directory with the Termonad source code.  From there, you
  can run `stack exec`:
  
  ```sh
  $ cd termonad/  # change to the termonad source code directory
  $ stack exec -- termonad
  ```
  
  `stack` will pick up the correct GHC version and libraries from the
  `stack.yaml` and `termonad.cabal` file.  `termonad` will be run in an
  environment with GHC available.  `termonad` will use this GHC and libraries to
  compile your `~/.config/termonad/termonad.hs` file.  It if succeeds, it should
  create a `~/.cache/termonad/termonad-linux-x86_64` binary.
  
  If you need extra Haskell libraries available when compiling your
  `~/.config/termonad/termonad.hs` file, you can specify them to `stack exec`:
  
  ```sh
  $ stack exec --package lens --package conduit -- termonad
  ```
  
  The problem with this is that `stack exec` changes quite a few of your
  environment variables.  It is not recommended to actually run Termonad from
  within `stack exec`.  After you run `stack exec -- termonad` and let it
  recompile your `~/.config/termonad/termonad.hs` file, exit Termonad.
  Re-run Termonad by calling it directly.  Termonad will notice that
  `~/.config/termonad/termonad.hs` hasn't changed since
  `~/.cache/termonad/termonad-linux-x86_64` has been recompiled, so it will
  directly execute `~/.cache/termonad/termonad-linux-x86_64`.
  
  #### Running with `nix`
  
  Building Termonad with `nix` (by running `nix-build` in the top
  directory) sets it up so that Termonad can see GHC.  Termonad should be able
  to compile the `~/.config/termonad/termonad.hs` file by default.
  
  If you're interested in how this works, or want to change which Haskell
  packages are available from your `~/.config/termonad/termonad.hs` file, please
  see the documentation in the
  [`.nix-helpers/termonad-with-packages.nix`](./.nix-helpers/termonad-with-packages.nix)
  file.
  
  ## Additional Info
  
  This section contains some additional info that may be helpful for using Termonad.
  
  ### Opening URLs by right-clicking
  
  It is possible to open a URL in a browser by right-clicking on it, and
  selecting `Open URL in browser`.  In order for this you work, you may
  have to setup your XDG defaults.  You can set the default browser to
  Firefox with a command like the following:
  
  ```console
  $ xdg-mime default firefox.desktop x-scheme-handler/http
  $ xdg-mime default firefox.desktop x-scheme-handler/https
  ```
  
  This `xdg-mime` executable comes from a package called `xdg-utils` in both
  Nixpkgs and Ubutun/Debian.
  
  ## Goals
  
  Termonad has the following goals:
  
  * fully configurable in Haskell
  
    There are already
    [many](https://gnometerminator.blogspot.com/p/introduction.html)
    [good](https://www.enlightenment.org/about-terminology.md)
    [terminal](http://software.schmorp.de/pkg/rxvt-unicode.html)
    [emulators](https://launchpad.net/sakura).  However, there are no terminal
    emulators fully configurable in Haskell.  Termonad fills this niche.
  
  * flexible
  
    Most people only need a terminal emulator that lets you change the font-size,
    cursor color, etc.  They don't need tons of configuration options.  Termonad
    should be for people that like lots of configuration options.  Termonad
    should provide many hooks to allow the user full control over its behavior.
  
  * stable
  
    Termonad should be able to be used everyday as your main terminal
    emulator.  It should not crash for any reason.  If you experience a crash,
    please file an issue or a pull request!
  
  * good documentation
  
    The [documentation](https://hackage.haskell.org/package/termonad) for
    Termonad on Hackage should be good.  You shouldn't have to guess at what
    certain data types or functions do.  If you have a hard time understanding
    anything in the documentation, please submit an issue or PR.
  
  ## Where to get help
  
  If you find a bug in Termonad, please either
  [send a PR](https://github.com/cdepillabout/termonad/pulls) fixing it or create
  an [issue](https://github.com/cdepillabout/termonad/issues) explaining it.
  
  If you just need help with configuring Termonad, you can either join the
  [Gitter room](https://gitter.im/termonad/Lobby) or
  [#termonad on irc.freenode.net](https://webchat.freenode.net/).
  
  ## Contributions
  
  Contributions are highly appreciated.  Termonad is currently missing many
  helpful configuration options and behavior hooks.  If there is something you
  would like to add, please submit an issue or PR.
  
  ## Maintainers
  
  - [cdepillabout](https://github.com/cdepillabout)
  