SETKEYCODES(8)

✨ SETKEYCODES(8) ✨

System Manager's Manual 🌸

💖 NAME 💖

setkeycodes, okay so this one loads kernel scancode-to-keycode mapping table entries 🎀

📝 SYNOPSIS 📝

setkeycodes [options] scancode keycode ...

🦋 DESCRIPTION 🦋

Okay bestie, so the setkeycodes command reads its arguments two at a time 👑. Each pair is a scancode (written in hexadecimal) followed by a keycode (written in decimal). For every pair, it tells the kernel keyboard driver to map that scancode to that keycode ✨. It's giving precision.

This command is only really useful for people with slightly unusual keyboards 🙈. Like, if you have a few keys that send scancodes the kernel doesn't recognize, this is your moment 💅.

🧠 THEORY 🧠

Okay so, every key press and key release on a usual PC keyboard sends a little series of scancodes 🔥. (You can peek at those with showkey -s, see showkey(1) 👀.) The kernel reads that stream and turns it into a stream of keycodes, which are the key press and release events 💜. (You can see keycodes with showkey.)

Here's the tea. Apart from a few scancodes with special meaning, the Pause key's sequence, the shiftstate-related scancodes, and the key up/down bit, the stream is made of two flavors: unescaped scancodes xx (7 bits), and escaped scancodes e0 xx (8+7 bits) 🌈. Each of these scancodes or scancode pairs can be given a matching keycode, anywhere in the range 1-127 🍓.

Let's say you've got a Macro key that sends e0 6f according to showkey(1). Then this command:

setkeycodes e06f 112

will assign keycode 112 to it 🧚. After that, loadkeys(1) can be used to decide what the key actually does ✨.

Heads up: some older kernels hardwire a low scancode range to the equivalent keycodes. If you try to remap those, setkeycodes will fail 💀.

🫧 2.6 KERNELS 🫧

In 2.6 kernels, keycodes live in the range 1-255 instead of 1-127 🌸. (Honestly, it might be safest to stick to 1-239 🫶.)

Warning, bestie 😭: in 2.6 kernels, raw mode (aka scancode mode) is not very raw at all. The code that showkey -s returns will change after you use setkeycodes. That's a kernel bug, not you 💅. See also showkey(1).

🎀 OPTIONS 🎀

• -C, --console=DEV — pick the console device you want to use 🖥️
• -V, --version — shows you the version number 🔢
• -h, --help — shows you the usage message 📖

🐛 BUGS 🐛

The keycodes of X have nothing to do with the ones in Linux, so no cap, they're not the same 🙃. Some unusual keys can be made visible under Linux, but not under X 😭.

🔗 SEE ALSO 🔗

dumpkeys(1), loadkeys(1), showkey(1), getkeycodes(8) 💜

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Source: kbd, 24 October 2024. Stay iconic, bestie 🌈💖✨