You can do this with a combination of ntfy and MacroDroid [1] or Tasker. With those apps, you can do things like "if I shake my phone, publish this message to this HTTP endpoint". And then you can subscribe to a ntfy topic via the ntfy CLI and execute a command.

Here's how you do it:

1. Install MacroDroid [1] on your phone

2. Set up an action in MacroDroid to publish a message to a ntfy topic via a HTTP GET (see [2])

3. On your computer, install the ntfy CLI and set up the ntfy-client systemd service (or use `ntfy subscribe mytopic 'echo $m'` or something similar); see instructions here: [3]

Here are some screenshots/videos of how to integrate MacroDroid and Tasker with ntfy [4]. Please note that the MacroDroid notes are a little out of date, since you can now use HTTP GET to publish messages, so you don't need to use the "Send intent" thing anymore, which means you don't need the ntfy app on your phone.

If you need more help, you can find me on Discord [4] and I'll help out.

[1] https://play.google.com/store/apps/details?id=com.arlosoft.m...

[2] https://ntfy.sh/docs/publish/#webhooks-send-via-get

[3] https://ntfy.sh/docs/subscribe/cli/#subscribe-to-multiple-to...

[4] https://ntfy.sh/docs/subscribe/phone/#integrations

[5] https://discord.gg/cT7ECsZj9w