How to send KDE5 desktop notification from a bash script?
On my install of Kubuntu 15.10 and KDE neon, notify-send command was not available until I installed the libnotify-bin package.
After installing libnotify-bin, notify-send works fine:
sudo apt-get install libnotify-bin
At least first two options should work, I just have a problem with notifications in KDE in general: https://bugs.launchpad.net/ubuntu/+source/kde-runtime/+bug/1547752
notify-send 'text'
kdialog --passivepopup 'text' 5