This little tool displays the native MacOS OSD via command line. Useful to embed in various scripts.
Install XCode
After downloading, to build, enter:
make release
See the built app in the .build/release folder afterwards. Don't forget to install XCode beforehand!
showosd - Shows an empty OSD (not very useful)
showosd brightness 40 - Shows brightness OSD at level 40 (out of 100)
showosd volume 60 - Shows volume OSD at level 60 (out of 100)
showosd volume - Shows volume with the last set value
showosd volume 4 16 - Volume OSD as 4 chiclets full out of the total possible 16
showosd brightness 15 64 - Shows voume OSD as 3 and 3/4 chiclets full
showosd mute 0 primary - Shows volume muted symbol on the primary display only
showosd keylight lock - Shows a locked keyboard birghtness symbol
showosd eject - Eject
showosd link - Shows link icon
showosd sleep - Shows a sleep icon and then initiates sleep ..zZz
Check out the following hammerspoon script.
This script allows you to control the volume of your external Display's brightness, contrast and volume via DDC (if you use an M1 mac) using m1ddc and also control your Yamaha AV Receiver through network. The script listens to the standard Apple keyboard media keys and shows the standard macOS Birghtness and Volume OSDs via uses showosd :
https://gist.github.com/waydabber/3241fc146cef65131a42ce30e4b6eab7
Thanks to @alin23 for all the help!
Enjoy!