Lock All The Computers

2025-07-23

I wanted a way to simultaneously lock all of the computers - a mixture of Linux, MacOS and Windows boxen - on my desk, when I'm going to step away. Here's what I came up with:

One button. And everything locks. Nice!

Here's how it works:

1. The mini keyboard is just 10 cheap mechanical keys wired up to a CH552 chip. It's configured to send CTRL+ALT+F13 through CTRL+ALT+F22 (F13 through F24 are absolutely valid "standard" key assignments, of course: it's just that the vast majority of keyboards don't have keys for them! This makes them excellent candidates for non-clashing personal-use function keys, but I like to append one or more modifier keys to the as well to be absolutely certain that I don't interact with things I didn't intend to!) when one of its keys are pressed.

2. The "lock" key is captured by my KVM tool Deskflow (which I migrated to when Barrier became neglected, which in turn I migrated to when I fell out of love with Synergy). It then relays this hotkey across to all currently-connected machines (Some of the other buttons on my mini keyboard are mapped to "jumping" my cursor to particular computers (if I lose it, which happens more often than I'd like to admit), and "locking" my cursor to the system it's on.).

3. That shortcut is captured by each recipient machine in different ways, as described below:

The OS-specific solutions are:

1. The Linux computers run LXDE, so I added a line to /etc/xdg/openbox/rc.xml to set a <keybind> that executes xscreensaver-command -lock.

2. For the Macs, I created a Quick Action in Automator that runs pmset displaysleepnow as a shell script (These boxes are configured to lock as soon as the screen blanks; if yours don't then you might need a more-sophisticated script.), and then connected that via Keyboard Shortcuts > Services.

3. On the Windows box, I've got AutoHotKey running anyway, so I just have it run { DllCall("LockWorkStation") } when it hears the keypress.

That's all there is to is! A magic "lock all my computers, I'm stepping away" button, that's much faster and more-convenient than locking two to five computers individually.