Turn virtual screen on or off from terminal?

[AaronKelley]

Does anyone know if there is a way to turn a dummy display on or off using a terminal command? I'm using a dummy display to force the system to 16:9 ratio. (Using a M2 MacBook Pro 16", which is 16:10 + notch bit at the top.) It works great, but I'm looking to script it to happen automatically as part of a job when I am opening up a set of applications.

Thanks!

[waydabber]

Here is a simple command line tool: https://github.com/waydabber/betterdisplaycli

Here is a simple command line tool: https://github.com/waydabber/createdummy

[AaronKelley]

Here is a simple command line tool: https://github.com/waydabber/createdummy

Has this tool been moved? The site appears to no longer exist.

[waydabber]

Yes, sorry, the createdummy tool was discontinued. You can now use betterdisplaycli to manage virtual screens (+ a lot more) with BetterDisplay.

https://github.com/waydabber/betterdisplaycli

[waydabber]

Some examples.

Creating a virtual screen (with an aspect ratio of 12:10):

betterdisplaycli create -devicetype=virtualscreen -virtualscreenname=MyVirtual -aspectWidth=12 -aspectHeight=10

Connecting a created virtual screen:

betterdisplaycli set -namelike=virtual -connected=on

Discard a virtual screen (use any identifier parameters to narrow the virtual screens to be discarded):

betterdisplaycli discard -namelike=virtual

Discard all virtual screens (rather dangerous, will happen with no comment):

betterdisplaycli discard

Rename a virtual screen from MyVirtual to TestVirtual:

betterdisplaycli set -name=MyVirtual -virtualscreenname=TestVirtual

Please note that while name is an identifier parameter to specify the device(s) you work on, virtualScreenName is a create/set/get parameter to modify the name of the virtual screen. The same with serial, modelNumber, vendorNumber.

[AaronKelley]

This looks great. Thanks. I will check it out.

[AaronKelley]

Thank you. It looks like this creates the dummy monitor and leaves the terminal app running, and terminating the app also kills the dummy.

I was able to use this along with displayplacer to achieve the automation that I was looking for. Thanks!

[waydabber]

Yes. You need to start the process in background to have the dummy keep running.