Ten Flying Fingers

tff (Ten Flying Fingers) is a Linux tool for remapping keys.

I learned touch typing several years ago, and I can write most keys without looking at the keyboard.

I want to keep my index fingers on "F" and "J" as much as possible (a.k.a. the "home row").

Currently, tff only works on Linux. PRs to support other plattforms are welcome.

Example combos.yaml

This combos.yaml file will print 1 if you overlap F J and 2 if you overlap J F:

combos:
  - keys: f j
    outKeys: 1
  - keys: j f
    outKeys: 2

The tff combos sub-command does the magic. It listens to the chosen device and translates events:

sudo $(go env GOPATH)/bin/tff combos combos.yaml

After starting above command move the input to an other window and see if you can produce 1 by overlapping J F. Overlapping F J emits 2.

Use tff print to see which characters your keys emit.

My config

my-combos.yaml is an example config.

Usage

Usage

Keys That Are Hard to Access

These keys are hard to access if you want to keep your index fingers on "F" and "J":

• Home (Pos1), End
• Arrow keys: Up, Down, Left, Right
• PageUp, PageDown
• Backspace
• Delete (Del)
• Escape (Esc)
• ...

Example: Choosing an Item from an Auto-Complete List

Imagine the active cursor is in the address bar of your browser.

You enter some characters to find a page you visited yesterday.

It appears in the drop-down box (autocomplete list)

Up to this point, you could keep your fingers on "F" and "J."

But now, how do you choose the item from the list without using the mouse?

Arrow-down is not easy to reach.

I Am Happy with Most Other Keys on the Keyboard

I know there are alternative keyboard layouts like Neo2 or Colemak, but I am happy with the default QWERTY/QWERTZ layout.

I want to extend the default layout, not replace it. I want to be able to use the keyboards of my teammates and family members as I am used to.

Combos: Using Several Keys at Once

Does a piano player hit one key after the other? No, a piano player hits several keys at once.

I want pressing (and holding) F and then J to be one combo, and J F another combo.

Initially, I used KMonad, but its syntax is not easy for me to understand and (as far as I know) it cannot differentiate between a F J and a J F combo.

I searched a bit and found go-evdev, a Go package for receiving and sending events on Linux.

Overlap vs Combo

While typing fluently, you may have some overlap between key presses. tff differentiates between hitting F and then J with an overlap time of 40ms. If both keys are pressed simultaneously and for longer, it is treated as one combination. Otherwise, it is interpreted as two separate keys.

You do not need to write in a staccato style.

Drawback

Keys that are part of a combo must not be emitted immediately. The code needs to wait a few milliseconds to determine if it is a combo or not. This delay exists but is almost unnoticeable.

Install

You can install tff via go install:

go install github.com/guettli/tff@latest

Use sudo because reading and writing from the Linux evdev needs root:

sudo $(go env GOPATH)/bin/tff -h

Keyboard Input Details on Linux

• Arch Linux Docs: "Keyboard Input"
• Linux Kernel Input Documentation

Trackpoint with Sandpaper

This is not directly related to the ttf tool, but you might find it interesting:

I want to keep my fingers close to the home row for moving the mouse cursor.

That's why I use a keyboard with a Trackpoint.

There are the well-known Lenovo keyboards, but there are alternatives like the Tex Shinobi.

To get maximum grip, I stick sandpaper on the Trackpoint.

Caution: Don't stick sandpaper on the Trackpoint of your laptop. If you close the laptop, the sandpaper may scratch the screen.

That’s why I use an external ThinkPad keyboard.

I Love Feedback

Did you find a typo? Do you have the same needs as I do? Do you know how to solve this?

Please send me feedback via a GitHub issue!

More

• Thomas WOL: Working Out Loud
• Desktop Tips
• I post updates to this article here: https://www.reddit.com/r/typing/