Firefox "minimize memory"

 One of the things I do is have a lot of open tabs, and firefox happily fills up all the available memory.

If you go to "about:memory" and click on "minimize memory usage" it will free up some much needed memory.

After clicking on this my total memory usage went from 31GB to 21GB.

Switching audio and adding a notification

 Once you get the audio switching working, it's nice to have a little bit of feedback, so add a little message with notify-send.

so CTRL+ALT+9 does

sh -c "pactl set-card-profile 0 output:hdmi-stereo;notify-send 'switch to hdmi'"

 

and CTRL+ALT+0 does:

 sh -c "pactl set-card-profile 0 output:analog-stereo; notify-send 'switch to headphone'"

Thanks to this page:

https://askubuntu.com/questions/60379/how-to-combine-two-commands-as-a-launcher

Switching the audio from HDMI to headphones

One of the things I do too frequently is to switch from my headphone output to the hdmi output. It's too hard to use the control panel, I want a keystroke to do it: 

After wrestling with pactl awhile I got it working.

 

If you run "pactl list cards" It will show you a list of profiles:

 "pactl set-card-profile 0 output:hdmi-stereo" 

"pactl set-card-profile 0 output:analog-stereo" 

would switch between the different outputs, so just add some Keyboard Shortcuts in the Settings.

Sometimes I have to kill gnome shell

Using Ubuntu 20.04, sometimes the screen will go black and I can't do anything. I can still see my mouse pointer and move it around, I can drop to a text console with CTRL+ALT+F4 and back with CTRL+ALT+F2 but it's not working right. I've found that if I get to a text console and login and then find the number of the gnome-shell process with "ps -ax | grep gnome-shell" then "kill -9 " it will close the gnome-shell and after a few seconds the system will relaunch it, bringing the system back to normal. It doesn't always work, but sometimes it's a lifesaver when it goes non responsive and you can save what you were working on.