You can make an AppleScript thing and call it from bash. I think this is the sort of documentation I used at one point: https://developer.apple.com/library/archive/documentation/La...

AppleScript does work well for this. It might also be nice for somebody to write a little UNIX-y command-line app that just allows you to pop up a notification, and potentially get a response to it. Maybe I will...

Thanks!

I'm using Pushover (https://pushover.net/) to send notifications to my Apple devices. To make use of it easier on command line I wrote a simple Python script which I've found to be very useful for things like allowing Transmission to send notifications when a download is finished or in scripts that do backup jobs which take a long time, letting me know when my Mac has booted, etc... Reply to this comment if you're interested in my script (note that the pushover site has good examples of how to call their API).

terminal-notifier does this.

https://github.com/julienXX/terminal-notifier

Pushover. Dead easy to use in a bash script etc with curl or wget. It also has an email gateway.