input-remapper/readme/usage.md

Usage

To open the UI to modify the mappings, look into your applications menu and search for 'Input Remapper'. You should be prompted for your sudo password as special permissions are needed to read events from /dev/input/ files. You can also start it via input-remapper-gtk.

First, select your device (like your keyboard) from the large dropdown on the top. Then you can already edit your keys, as shown in the screenshots.

In the text input field, type the key to which you would like to map this key. More information about the possible mappings can be found below.

Changes are saved automatically. Afterwards press the "Apply" button.

To change the mapping, you need to use the "Stop Injection" button, so that the application can read the original keycode. It would otherwise be invisible since the daemon maps it independently of the GUI.

Troubleshooting

If stuff doesn't work, check the output of input-remapper-gtk -d and feel free to open up an issue here. Make sure to not post any debug logs that were generated while you entered private information with your device. Debug logs are quite verbose.

If input-remapper or your presets prevents your input device from working at all due to autoload, please try to unplug and plug it in twice. No injection should be running anymore.

Combinations

Change the key of your mapping (Change Key - Button) and hold a few of your device keys down. Releasing them will make your text cursor jump into the mapping column to type in what you want to map it to.

Combinations involving Modifiers might not work. Configuring a combination of two keys to output a single key will require you to push down the first key, which of course ends up injecting that first key. Then the second key will trigger the mapping, because the combination is complete. This is not a bug. Otherwise every combination would have to automatically disable all keys that are involved in it.

For example a combination of LEFTSHIFT + a for b would write "B" instead, because shift will be activated before you hit the "a". Therefore the environment will see shift and a "b", which will then be capitalized.

Consider using a different key for the combination than shift. You could use KP1 + a and map KP1 to disable.

The second option is to release the modifier in your combination by writing the modifier one more time. This will write lowercase "b" characters. To make this work shift has to be injected via key-mappers devices though, which just means it has to be forwarded. So the complete mapping for this would look like:

• Shift L + a -> key(Shift_L).hold(b)
• Shift L -> Shift_L

Writing Combinations

You can write Control_L + a as mapping, which will inject those two keycodes into your system on a single key press. An arbitrary number of names can be chained using +.

UI Shortcuts

• ctrl + del stops the injection (only works while the gui is in focus)
• ctrl + q closes the application
• ctrl + r refreshes the device list

Key Names

Check the autocompletion of the GUI for possible values. You can also obtain a complete list of possiblities using input-remapper-control --symbol-names.

Input-remapper only recognizes symbol names, but not the symbols themselves. So for example, input-remapper might (depending on the system layout) know what a minus is, but it doesn't know -.

Key names that start with KEY_ are keyboard layout independent constants that might not result in the expected output. For example using KEY_Y would result in "z" if the layout of the environment is set to german. Using y on the other hand would correctly result in "y" to be written.

Limitations

If your fingers can't type it on your keyboard, input-remapper can't inject it.

The available symbols depend on the environments keyboard layout, and only those that don't require a combination to be pressed can be used without workarounds (so most special characters need some extra steps to use them). Furthermore, if your configured keyboard layout doesn't support the special character at all (not even via a combination), then it also won't be possible for input-remapper to map that character at all.

For example, mapping a key to an exclamation mark is not possible if the keyboard layout is set to german. However, it is possible to mimic the combination that would be required to write it, by writing Shift_L + 1 into the mapping.

This is because input-remapper creates a new virtual keyboard and injects numeric keycodes, and it won't be able to inject anything a usb keyboard wouldn't been able to. This has the benefit of being compatible to all display servers, but means the environment will ultimately decide which character to write.

External tools

Repositories listed here are made by input-remappers users. Feel free to extend. Beware, that I can't review their code, so use them at your own risk (just like everything).

• input-remapper-xautopresets: https://github.com/DreadPirateLynx/input-remapper-xautopresets

Advanced

Configuration Files

If you don't have a graphical user interface, you'll need to edit the configuration files. All configuration files need to be valid json files, otherwise the parser refuses to work.

Note for the Beta branch: All configuration files are copied to: ~/.config/input-remapper/beta_VERSION/

The default configuration is stored at ~/.config/input-remapper/config.json, which doesn't include any mappings, but rather other parameters that are interesting for injections. The current default configuration as of 1.5 looks like, with an example autoload entry:

{
  "autoload": {
      "Logitech USB Keyboard": "preset name"
    },
  "version": "1.5"
}

preset name refers to ~/.config/input-remapper/presets/device name/preset name.json. The device name can be found with sudo input-remapper-control --list-devices.

Preset

The preset files are a collection of mappings. Here is an example configuration for preset "a" for the "gamepad" device: ~/.config/input-remapper/presets/gamepad/a.json

{
    "1,307,1": {
        "target_uinput": "keyboard",
        "output_symbol": "k(2).k(3)",
        "macro_key_sleep_ms": 100
    },
    "1,315,1+1,16,1": {
        "target_uinput": "keyboard",
        "output_symbol": "1"
    },
    "3,1,0": {
        "target_uinput": "mouse",
        "output_type": 2,
        "output_code": 1,
        "gain": 0.5
    }
}

This preset consists of three mappings.

• The first maps the key event with code 307 to a macro and sets the time between injected events of macros to 100 ms. The macro injects its events to the virtual keyboard.
• The second mapping is a key combination, chained using +.
• The third maps the y-Axis to the y-Axis on the virtual mouse.

Mapping

As shown above, the mapping is part of the preset. It consists of the input-combination and the mapping parameters.

<input-combination>: {
    <parameter 1>: <value1>,
    <parameter 2>: <value2>
}

The input-combination is a string like "EV_TYPE, EV_CODE, EV_VALUE + ...". EV_TYPE and EV_CODE describe the input event. Use the program evtest to find Available types and codes. See also the evdev documentation

The EV_VALUE describes the intention of the input. A value of 0 means that the event will be mapped to an axis. A non-zero value means that the event will be treated as a key input.

If the event type is 3 (EV_ABS) (as in: map a joystick axis to a key or macro) the value can be between -100 [%] and 100 [%]. The mapping will be triggered once the joystick reaches the position described by the value.

If the event type is 2 (EV_REL) (as in: map a relative axis (e.g. mouse wheel) to a key or macro) the value can be anything. The mapping will be triggered once the speed and direction of the axis is higher than described by the value.

The following table contains all possible parameters and their default values:

Parameter	Default	Type	Description
target_uinput		string	The UInput to which the mapped event will be sent
output_symbol		string	The symbol or macro string if applicable
output_type		int	The event type of the mapped event
output_code		int	The event code of the mapped event
release_combination_keys	true	bool	If release events will be sent to the forwarded device as soon as a combination triggers see also #229
Macro settings
macro_key_sleep_ms	20	positive int
Axis settings
deadzone	0.1	float ∈ (0, 1)	The deadzone of the input axis
gain	1.0	float	Scale factor when mapping an axis to an axis
expo	0	float ∈ (-1, 1)	Non liniarity factor see also GeoGebra
EV_REL output
rate	60	positive int	The frequency [Hz] at which EV_REL events get generated (also effects mouse and wheel macro)
rel_speed	100	positive int	The base speed of the relative axis, compounds with the gain (also effects mouse and wheel macro)
EV_REL as input
rel_input_cutoff	100	positive int	The absolute value at which a EV_REL axis is considered at its maximum
release_timeout	0.05	positive float	The time [s] until a relative axis is considered stationary if no new events arrive

CLI

input-remapper-control

--command requires the service to be running. You can start it via systemctl start input-remapper or sudo input-remapper-service if it isn't already running (or without sudo if your user has the appropriate permissions).

Examples:

Description	Command
Load all configured presets for all devices	input-remapper-control --command autoload
If you are running as root user, provide information about the whereabouts of the input-remapper config	input-remapper-control --command autoload --config-dir "~/.config/input-remapper/"
List available device names for the --device parameter	sudo input-remapper-control --list-devices
Stop injecting	input-remapper-control --command stop --device "Razer Razer Naga Trinity"
Load ~/.config/input-remapper/presets/Razer Razer Naga Trinity/a.json	input-remapper-control --command start --device "Razer Razer Naga Trinity" --preset "a"
Loads the configured preset for whatever device is using this /dev path	/bin/input-remapper-control --command autoload --device /dev/input/event5

systemctl

Stopping the service will stop all ongoing injections

sudo systemctl stop input-remapper
sudo systemctl start input-remapper
systemctl status input-remapper

Testing your Installation

The following commands can be used to make sure it works:

sudo input-remapper-service &
input-remapper-control --command hello

should print Daemon answered with "hello". And

sudo input-remapper-control --list-devices

should print Found "...", .... If anything looks wrong, feel free to create an issue.