xremap/README.md

# 𝑋𝑟𝑒𝑚𝑎𝑝 :keyboard: [![cargo](https://github.com/k0kubun/xremap/actions/workflows/build.yml/badge.svg)](https://github.com/k0kubun/xremap/actions/workflows/build.yml)

`xremap` is a key remapper for Linux. Unlike `xmodmap`, it supports app-specific remapping and Wayland.

## Concept

* **Fast** - Xremap is written in Rust, which is faster than JIT-less interpreters like Python.

* **Cross-platform** - Xremap uses `evdev` and `uinput`, which works whether you use X11 or Wayland.

* **Language-agnostic** - The config is JSON-compatible. Generate it from any language,
  e.g. [Ruby](https://github.com/xremap/xremap-ruby), [Python](https://github.com/xremap/xremap-python).

## Features

* Remap any keys, e.g. Ctrl or CapsLock.
* Remap any key combination to another, even to a key sequence.
* Remap a key sequence as well. You could do something like Emacs's `C-x C-c`.
* Remap a key to two different keys depending on whether it's pressed alone or held.
* Application-specific remapping. Even if it's not supported by your application, xremap can.
* Automatically remap newly connected devices by starting xremap with `--watch`.
* Support [Emacs-like key remapping](example/emacs.yml), including the mark mode.
* Trigger commands on key press/release events.
* Use a non-modifier key as a virtual modifier key.

## Installation

Download a binary from [Releases](https://github.com/k0kubun/xremap/releases).

If it doesn't work, please [install Rust](https://doc.rust-lang.org/cargo/getting-started/installation.html)
and run one of the following commands:

```bash
cargo install xremap --features x11   # X11
cargo install xremap --features gnome # GNOME Wayland
cargo install xremap --features sway  # Sway
cargo install xremap                  # Others
```

You may also need to install `libx11-dev` to run the `xremap` binary for X11.

### Arch Linux

If you are on Arch Linux and X11, you can install [xremap-x11-bin](https://aur.archlinux.org/packages/xremap-x11-bin/) from AUR.

### NixOS

If you are using NixOS, xremap can be installed and configured through a [flake](https://github.com/xremap/nix-flake/).

## Usage

Write [a config file](#Configuration) directly, or generate it with
[xremap-ruby](https://github.com/xremap/xremap-ruby) or [xremap-python](https://github.com/xremap/xremap-python).
Then run:

```
sudo xremap config.yml
```

<details>
<summary>If you want to run xremap without sudo, click here.</summary>

### Running xremap without sudo

To do so, your normal user should be able to use `evdev` and `uinput` without sudo.
In Ubuntu, this can be configured by running the following commands and rebooting your machine.

```bash
sudo gpasswd -a YOUR_USER input
echo 'KERNEL=="uinput", GROUP="input", TAG+="uaccess"' | sudo tee /etc/udev/rules.d/input.rules
```

#### Arch Linux

The following can be used on Arch.

```bash
lsmod | grep uinput
```
If this module is not loaded, add to `/etc/modules-load.d/uinput.conf`:
```bash
uinput
```
Then add udev rule.

```bash
echo 'KERNEL=="uinput", GROUP="input", MODE="0660"' | sudo tee /etc/udev/rules.d/99-input.rules
```

#### Other platforms

In other platforms, you might need to create an `input` group first
and run `echo 'KERNEL=="event*", NAME="input/%k", MODE="660", GROUP="input"' | sudo tee /etc/udev/rules.d/input.rules` as well.

If you do this, in some environments, `--watch` may fail to recognize new devices due to temporary permission issues.
Using `sudo` might be more useful in such cases.

---

</details>

See the following instructions for your environment to make `application`-specific remapping work.

### X11

If you use `sudo` to run `xremap`, you may need to run `xhost +SI:localuser:root` if you see `No protocol specified`.

### GNOME Wayland

Install xremap's GNOME Shell extension from [this link](https://extensions.gnome.org/extension/5060/xremap/),
switching OFF to ON.

<details>
<summary>If you use <code>sudo</code> to run <code>xremap</code>, also click here.</summary>

Update `/usr/share/dbus-1/session.conf` as follows, and reboot your machine.

```diff
   <policy context="default">
+    <allow user="root"/>
     <!-- Allow everything to be sent -->
     <allow send_destination="*" eavesdrop="true"/>
     <!-- Allow everything to be received -->
```

</details>

## Configuration
Your `config.yml` should look like this:

```yml
modmap:
  - name: Except Chrome
    application:
      not: Google-chrome
    remap:
      CapsLock: Esc
keymap:
  - name: Emacs binding
    application:
      only: Slack
    remap:
      C-b: left
      C-f: right
      C-p: up
      C-n: down
```

See also: [example/config.yml](example/config.yml) and [example/emacs.yml](example/emacs.yml)

### modmap

`modmap` is for key-to-key remapping like xmodmap.
Note that remapping a key to a modifier key, e.g. CapsLock to Control\_L,
is supported only in `modmap` since `keymap` handles modifier keys differently.

```yml
modmap:
  - name: Name # Optional
    remap: # Required
      # Replace a key with another
      KEY_XXX: KEY_YYY # Required
      # Dispatch different keys depending on whether you hold it or press it alone
      KEY_XXX:
        held: KEY_YYY # Required
        alone: KEY_ZZZ # Required
        alone_timeout_millis: 1000 # Optional
      # Hook `keymap` action on key press/release events.
      KEY_XXX:
        press: { launch: ["xdotool", "mousemove", "0", "7200"] } # Required
        release: { launch: ["xdotool", "mousemove", "0", "0"] } # Required
    application: # Optional
      not: [Application, ...]
      # or
      only: [Application, ...]
```

For `KEY_XXX` and `KEY_YYY`, use [these names](https://github.com/emberian/evdev/blob/1d020f11b283b0648427a2844b6b980f1a268221/src/scancodes.rs#L26-L572).
You can skip `KEY_` and the name is case-insensitive. So `KEY_CAPSLOCK`, `CAPSLOCK`, and `CapsLock` are the same thing.
Some [custom aliases](src/config/key.rs) like `SHIFT_R`, `CONTROL_L`, etc. are provided.

If you specify a map containing `held` and `alone`, you can use the key for two purposes.
The key is considered `alone` if it's pressed and released within `alone_timeout_millis` (default: 1000)
before any other key is pressed. Otherwise it's considered `held`.

### keymap

`keymap` is for remapping a sequence of key combinations to another sequence of key combinations or other actions.

```yml
keymap:
  - name: Name # Optional
    remap: # Required
      # Key press -> Key press
      MOD1-KEY_XXX: MOD2-KEY_YYY
      # Sequence (MOD1-KEY_XXX, MOD2-KEY_YYY) -> Key press (MOD3-KEY_ZZZ)
      MOD1-KEY_XXX:
        remap:
          MOD2-KEY_YYY: MOD3-KEY_ZZZ
        timeout_millis: 200 # Optional. No timeout by default.
      # Key press (MOD1-KEY_XXX) -> Sequence (MOD2-KEY_YYY, MOD3-KEY_ZZZ)
      MOD1-KEY_XXX: [MOD2-KEY_YYY, MOD3-KEY_ZZZ]
      # Execute a command
      MOD1-KEY_XXX:
        launch: ["bash", "-c", "echo hello > /tmp/test"]
      # Let `with_mark` also press a Shift key (useful for Emacs emulation)
      MOD1-KEY_XXX: { set_mark: true } # use { set_mark: false } to disable it
      # Also press Shift only when { set_mark: true } is used before
      MOD1-KEY_XXX: { with_mark: MOD2-KEY_YYY }
      # The next key press will ignore keymap
      MOD1-KEY_XXX: { escape_next_key: true }
      # Set mode to configure Vim-like modal remapping
      MOD1-KEY_XXX: { set_mode: default }
    application: # Optional
      not: [Application, ...]
      # or
      only: [Application, ...]
    mode: default # Optional
default_mode: default # Optional
```

For `KEY_XXX`, use [these names](https://github.com/emberian/evdev/blob/1d020f11b283b0648427a2844b6b980f1a268221/src/scancodes.rs#L26-L572).
You can skip `KEY_` and the name is case-insensitive. So `KEY_CAPSLOCK`, `CAPSLOCK`, and `CapsLock` are the same thing.

For the `MOD1-` part, the following prefixes can be used (also case-insensitive):

* Shift: `SHIFT-`
* Control: `C-`, `CTRL-`, `CONTROL-`
* Alt: `M-`, `ALT-`
* Windows: `SUPER-`, `WIN-`, `WINDOWS-`

You can use multiple prefixes like `C-M-Shift-a`.
You may also suffix them with `_L` or `_R` (case-insensitive) so that
remapping is triggered only on a left or right modifier, e.g. `Ctrl_L-a`.

If you use `virtual_modifiers` explained below, you can use it in the `MOD1-` part too.

### application

`application` can be used for both `modmap` and `keymap`, which allows you to specify application-specific remapping.

```yml
application:
  not: Application
  # or
  not: [Application, ...]
  # or
  only: Application
  # or
  only: [Application, ...]
```

The application name can be specified as a normal string to exactly match the name,
or a regex surrounded by `/`s like `/application/`.

To check the application names, you can use the following commands:

#### X11

```
$ wmctrl -x -l
0x02800003  0 slack.Slack           ubuntu-jammy Slack | general | ruby-jp
0x05400003  0 code.Code             ubuntu-jammy application.rs - xremap - Visual Studio Code
```

You may use the entire string of the third column (`slack.Slack`, `code.Code`),
or just the last segment after `.` (`Slack`, `Code`).

#### GNOME Wayland

```
busctl --user call org.gnome.Shell /com/k0kubun/Xremap com.k0kubun.Xremap WMClass
```

#### Sway

```
swaymsg -t get_tree
```

Locate `app_id` in the output.

#### application-specific key overrides

Sometimes you want to define a generic key map that is available in all applications, but give specific keys in that map their own definition in specific applications. You can do this by putting the generic map at the bottom of the config, after any specific overrides, as follows.

```yml
# Emacs-style word-forward and word-back
keymap:
  - name: override to make libreoffice-writer go to end of word but before final space like emacs
    application:
      only: libreoffice-writter
    remap:
      Alt-f: [right, C-right, left]
  - name: generic for all apps
    remap:
      Alt-f: C-right
      Alt-b: C-left
```

Note how Alt-f and Alt-b work in all apps, but the definition of Alt-f is slightly different in LibreOffice Writer. When that app is active, the first definition overrides the second definition; but for any other app, only the second definition is found. This is because xremap uses the first matching definition that it finds.

### virtual\_modifiers

You can declare keys that should act like a modifier.

```yml
virtual_modifiers:
  - CapsLock
keymap:
  - remap:
      CapsLock-i: Up
      CapsLock-j: Left
      CapsLock-k: Down
      CapsLock-l: Right
```

### keypress_delay_ms

Some applications have trouble understanding synthesized key events, especially on
Wayland. `keypress_delay_ms` can be used to workaround the issue.
See [#179](https://github.com/k0kubun/xremap/issues/179) for the detail.

## License

`xremap` is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).