Portmaster - ports-mgmt/portmaster

You can use Portmaster to manage installing, deinstalling, and updating all your installed packages via ports.

Install portmaster
cd /usr/ports/ports-mgmt/portmaster
make install clean
or
pkg install portmaster

To check all installed ports and update as necessary use the following command:
portmaster -a

or optionally with additional useful options:
portmaster -abdwG

-a check all ports, update as necessary
-b create and keep a backup package of an installed port
-d always clean distfiles
-w save old shared libraries before deinstall
-G prevents 'make config'

To list the installed ports that have an update available:
pkg version -vPL=

or with portmaster:
portmaster -L | grep -i "new version" -B 1

To automate the portsnap/portmaster update process and notify you via email that an update is available, add the following to root's crontab:

portsnap auto > /dev/null; pkg version -vPL=

When you receive the email notification, login and install the updates with portmaster:
portmaster -a