notify-send - Linux

Overview

The notify-send command is a utility in Linux that triggers a desktop notification to appear on the user’s screen. Notifications created by notify-send are useful for alerting the user after a long-running process has completed or for displaying system information in a non-intrusive way. The command interfaces with the desktop’s native notification system, making it widely applicable in desktop scripting and automation.

Syntax

The basic syntax of the notify-send command is:

notify-send [OPTIONS] <SUMMARY> [BODY]
  • <SUMMARY>: The title or main text of the notification.
  • [BODY]: The optional secondary text which provides more detail.

Options/Flags

The notify-send command offers several options:

  • -u, --urgency=LEVEL: Sets the urgency level (low, normal, critical).
  • -t, --expire-time=TIME: Time in milliseconds for the notification to expire. The default is to follow system settings or remain until dismissed.
  • -i, --icon=ICON[,ICON...]: Specifies an icon filename or stock icon to display alongside the notification.
  • -c, --category=TYPE[,TYPE...]: Specifies the notification category.
  • -h, --hint=TYPE:NAME:VALUE: Supplies extra data in the form of key-value pairs.

Typical use cases involve specifying urgency, an icon, and expiration time to tailor the notification depending on the context it’s used.

Examples

  1. Basic Notification:

    notify-send "Hello, World!"

    Displays a basic notification with the text “Hello, World!”.

  2. Notification with Title and Body:

    notify-send "Reminder" "Meeting at 3 PM"

    Shows a notification titled “Reminder” with more details in the body.

  3. Notification with Urgency and Icon:

    notify-send -u critical -i error "Alert" "Temperature too high!"

    Displays a critical urgency notification with an error icon.

  4. Notification with Expiration Time:

    notify-send -t 10000 "Break" "Time to relax!"

    This notification will expire after 10 seconds.

Common Issues

  • Urgency Levels Not Respected: Some desktop environments may not support different urgency levels or may treat them the same.
  • Persistent Notifications: If -t 0 is used, notifications may not expire as intended depending on the desktop settings.

Workaround: Ensure compatibility with your desktop environment, and avoid setting a zero timeout unless desired.

Integration

Script Completion Notification:
Imagine running a backup script and wanting a notification when it finishes:

#!/bin/bash
# Backup script example
tar -czf backup.tar.gz /my/directory
notify-send "Backup Complete" "Your files are now safe."

Combining with Cron Jobs:
Schedule a reminder every Monday morning using cron:

0 9 * * 1 notify-send "Weekly Meeting" "Don't forget the team meeting at 10 AM."
  • zenity: Tool for displaying dialog boxes in the GUI.
  • xmessage: Older tool for displaying alert text in a window.

For more advanced usage, refer to the freedesktop.org notifications specifications.