Send macOS User Notifications. More information: https://github.com/julienXX/terminal-notifier.
terminal-notifier -group {{tldr-info}} -title {{TLDR}} -message '{{TLDR rocks}}'
echo '{{Piped Message Data!}}' | terminal-notifier -sound {{default}}
terminal-notifier -message '{{Check your Apple stock!}}' -open '{{http://finance.yahoo.com/q?s=AAPL}}'
terminal-notifier -message '{{Imported 42 contacts.}}' -activate {{com.apple.AddressBook}}