#352 macOS Notifications with Ruby

Modern alternatives to the old growl notification system for ruby programming on macOS: osascript, terminal-notifier

Notes

Growl was a notification system for macOS developed in 2004. It was quite commonly used with ruby for desktop notifications, but has since become obsolete.

What are modern alternatives specifically for local/desktop messaging circa 2025? The two main ones that come to mind:

• calling AppleScript/oascript - limited and poorly supported
• using the terminal-notifier gem - much better and actively maintained solution

Using AppleScript/oascript

The osascript command can be used to execute AppleScript. Although poorly supported these days, some of the notification features still work.

For example, to always show a message in the foreground, can tell the “System Events” application to display dialog or display alert. Note that the display notification command no longer seems to work.

A dialog is displayed with both an OK and Cancel button:

osascript -e 'tell app "System Events" to display dialog "Hello World"'

An alert only has an OK button:

osascript -e 'tell app "System Events" to display alert "Hello World"'

osascript -e 'tell app "System Events" to display notification "Hello World"'

From ruby, oascript can be invoked as a shell command. See oascript-example.rb:

#! /usr/bin/env ruby
app = "System Events"
message = "Ruby task finished"
system("osascript -e 'tell app \"#{app}\" to display alert \"#{message}\"'")

terminal-notifier gem

The terminal-notifier gem is used to send user notifications on macOS 10.10 or higher. It may be used from the command line or from ruby code.

Running from the command line:

terminal-notifier -title ProjectX -subtitle "new tag detected" -message "Finished"

On first use, the system will prompt for permissions:

Subsequent messages will be displayed as expected:

Notifications may also be invoked directly from ruby using the gem’s API. See terminal-notifier-example.rb for an example:

#! /usr/bin/env ruby
require 'terminal-notifier'
TerminalNotifier.notify('Task finished successfully!', title: 'Ruby Script', subtitle: 'Done')

Execute the script:

ruby ./terminal-notifier-example.rb

The message is displayed as expected in the notification centre:

Credits and References

• Growl (deprecated)
  • https://en.wikipedia.org/wiki/Growl_(software)
  • https://growl.github.io/growl/
  • https://github.com/tj/growl/tree/master
  • https://formulae.brew.sh/cask/growlnotify
• AppleScript/ oascript
  • https://en.wikipedia.org/wiki/AppleScript
  • https://stackoverflow.com/questions/5588064/how-do-i-make-a-mac-terminal-pop-up-alert-applescript
• terminal-notifier
  • https://github.com/julienXX/terminal-notifier
  • https://rubygems.org/gems/terminal-notifier