{"id":47158,"date":"2024-09-03T09:33:18","date_gmt":"2024-09-03T09:33:18","guid":{"rendered":"https:\/\/ubuntuhandbook.org\/?p=47158"},"modified":"2024-09-03T09:33:18","modified_gmt":"2024-09-03T09:33:18","slug":"remap-keyboard-keys-ubuntu","status":"publish","type":"post","link":"https:\/\/ubuntuhandbook.org\/index.php\/2024\/09\/remap-keyboard-keys-ubuntu\/","title":{"rendered":"Remap Keyboard Keys in Ubuntu 24.04 without 3rd Party Apps"},"content":{"rendered":"

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This is a step by step tutorial shows how to manually remap (or disable) keyboard keys in Ubuntu without using any third-party apps.<\/p>\n

There are a few free open-source applications that can re-map your mouse, keyboard, and other input devices keys in Linux. As far as know, they include input remmaper<\/a> and AntiMicroX<\/a>.<\/p>\n

For GNOME, the default desktop for Ubuntu and Fedora Workstation, there’s popular GNOME Tweak tool (available in AppCenter\/GNOME Software) with options to remap Ctrl, Alt, and Caps Lock keys.<\/p>\n

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GNOME Tweaks<\/p><\/div>\n

<\/p>\n

Without the tools mentioned above, Linux also provides system config files to manually re-map your keyboard key-codes. And, here I’m going to show you how to do the trick in Ubuntu (tested in 24.04).<\/p>\n

NOTE: The method in this tutorial can be only used for simple 1:1 key remaps.<\/b><\/p>\n

Step 1: Find out the scancodes of the keys you want to remap<\/h3>\n

When you pressing a physical key on keyboard, it sends a scancode<\/b> to the computer. Then, your system maps the scancode to a virtual keycode<\/b>. By re-mapping the scancode<\/code> to another keycode<\/code> as you want will do the job.<\/p>\n

1.<\/b> To find out the scancode of the keys, first, press Ctrl+Alt+T<\/code> on keyboard to open up a terminal window. When it opens, run command:<\/p>\n

evtest<\/pre>\n
If command not found, run sudo apt install evtest<\/code> to install. And in the terminal output, it will print all the available input devices.<\/p>\n
In my case, I have laptop’s built-in keyboard (AT Translated Set 2 keyboard) and wireless keyboard (YICHIP Wireless Device) using a USB receiver.<\/p>\n
As the screenshot below shows, I have to type 7<\/b>, the number in \/dev\/input\/event7<\/code>, for the wireless keyboard.<\/p>\n
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2.<\/b> Once you input the corresponding number and hit enter in last command, you can then hit any key<\/b> on keyboard. The terminal will output the information about what you pressed\/released.<\/p>\n
In the screenshot below, the value code (e.g., 70028, 70025, 700e0, 700e2) are the scancodes for the corresponding key press\/release.<\/p>\n
NOTE: Different keyboards have different scan-codes for even same key-codes. In my case, the built-in laptop keyboard includes 1d, 1e, 1f, 20, etc scancodes, while the wireless keyboard has 700e0, 700e2, 70025, and so forth.<\/b><\/p>\n
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Step 2: Get the ID of your Keyboard<\/h3>\n
Before remapping, you also need to find out the information to identify your keyboard.<\/p>\n
For USB keyboard<\/b>, simply run the command below in terminal (Ctrl+Alt+T):<\/p>\n
lsusb<\/pre>\n
In the output, find out your keyboard according to its name. And write down the ID. It’s usually xxxx:xxxx, while the first 4 numbers is vendor ID<\/strong> and later 4 is product ID<\/strong>.<\/p>\n
Also, run the command below to tell the bus ID<\/strong> (usually 03 in hex):<\/p>\n
cat \/usr\/include\/linux\/input.h |grep BUS_*<\/pre>\n
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If it’s NOT USB device<\/b>, try running the command below instead to get the modalias<\/strong>:<\/p>\n
cat \/sys\/class\/input\/event7\/device\/modalias<\/pre>\n
In the command, replace event7<\/b> for the correct device according to the evtest<\/code> command in “Step 1”. In terminal output, copy the “input:b****v****p****e****”<\/p>\n
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Step 3: Add udev rule to remap keyboard key<\/h3>\n
After found out the scancodes of the keys you want to remap, and the ID for your keyboard device, you can then edit the udev config file to remap.<\/p>\n
First, in Ubuntu Linux there’s built-in \/usr\/lib\/udev\/hwdb.d\/60-keyboard.hwdb<\/code> config file for scancode<\/code> and keycode<\/code> mapping.<\/p>\n
However, it’s recommended to create a rule under \/etc\/<\/code> directory for user custom key mapping.<\/p>\n
1.<\/b> First, run command in terminal (Ctrl+Alt+T) to create and edit the udev config file:<\/p>\n
sudo gnome-text-editor \/etc\/udev\/hwdb.d\/61-keyboard-local.hwdb<\/pre>\n
Here, replace gnome-text-editor<\/code> with gedit<\/code> for 22.04, or mousepad<\/code> for XFCE, pluma<\/code> for MATE, or nano<\/code> command line text editor that works in most desktop environments.<\/p>\n
2.<\/b> When files opens, add similar lines below:<\/p>\n
evdev:input:b0003v3151p3020e0200*\r\n KEYBOARD_KEY_7001e=reserved\r\n KEYBOARD_KEY_700e2=leftctrl\r\n KEYBOARD_KEY_700e0=leftalt<\/pre>\n
The first line evdev:input:b0003v3151p3020e0200*<\/code> is used to identify which keyboard device to remap. While input:b0003v3151p3020e0200<\/code> is the modalias you got in “Step 2”.<\/p>\n
In my case, it can be replaced with evdev:input:b0003<\/b>v3151<\/b>p3020<\/b>*<\/code>. While, 0003 is the USB bus ID, 3151 is vendor ID, and 3020 is product ID. And, both has * in the end.<\/p>\n
And following lines tell to remap the scan-codes to your desired key-codes:<\/p>\n