I wrote a quick little script this morning to notify myself of updates
to MacPorts via the Mac OS X notification app Growl. The script
is a bash script that is designed to run as root from a cronjob (as the
port sync command requires root permissions). You can find the script
committed in my dotfiles repository on github. For convenience, I
pasted the script below, though the copy on github will always be
the most up-to-date copy:
Assuming the script is at ~/bin/port-update-notifier, you can install
the script to a crontab by running sudo crontab -e, then adding the
line 0 12 * * * /Users/<username>/bin/port-update-notifier to the end
of the file (substituting <username> for your username, or wherever
you've put the script). I've chosen to run the script every day at noon
because my computer is likely to be on and connected to a network.