sudo port -v selfupdate

http://trac.macosforge.org/projects/macports/wiki/UsingMacPortsQuickStart

After installing MacPorts, try running a selfupdate to grab all the latest MacPorts Portfiles (Portfiles contain information about how to install MacPorts software "ports"). You will need to run this command as an administrator, and it requires root access, so you'll need to "sudo":

sudo port selfupdate

Running MacPorts commands, you can add the -v command for more verbose ("v" for "verbose") output if you'd like more detail about what MacPorts is attempting to do:

sudo port -v selfupdate

If you are a developer and would like even more specific accounting of what MacPorts is doing, add the -d flag.

port (Update outdated portfiles)

Bash, mac, osx

Bash