Ubuntu comes with some indicator panel applet on the top right corner of your screen, for example on my laptop, i have sound, date, battery, language, network and session indicator. The question is how to refresh these indicators.
Why you want to refresh the indicators? because sometimes the indicators are not up-to-date in terms of data and you need to refresh it somehow. Like for example i uninstall a music player, but on the sound indicator, that music player is still there with a blank icon.
So how do i refresh these indicators? to refresh indicator panel on ubuntu we can use 'killall' command, this will not close the indicator permanently, it will only restart the indicator (stop and then start).Example:
The command above will restart the sound indicator panel, here's list of other indicator name that you can use to restart/refresh :