notify-send — Use the current desktop environment's notification system to create a notification. More information

Show a notification with the title "Test" and the content "This is a test"

notify-send "Test" "This is a test"

Show a notification with a custom icon

notify-send {{[-i|--icon]}} {{icon.png}} "{{Test}}" "{{This is a test}}"

Show a notification for 5 seconds

notify-send {{[-t|--expire-time]}} 5000 "{{Test}}" "{{This is a test}}"

Show a notification with the specified urgency level (default: normal)

notify-send {{[-u|--urgency]}} {{low|normal|critical}} "{{Test}}" "{{This is a test}}"

Show a notification with an app's icon and name

notify-send "{{Test}}" {{[-i|--icon]}} {{google-chrome}} {{[-a|--app-name]}} "{{Google Chrome}}"