Do you want to do this in real-time? This is not an elegant solution, but it is easy... just write a script that will follow your ftp server's logfile, and format the lines as they come in. If you don't need the real-time aspect, then write a script that runs on demand, or from cron, to parse the server log.

You didn't mention the platform or server prduct, but with ProFTP on my Linux box the files of interest are /var/log/proftpd.log and /var/log/xferlog.

Like I said, it ain't glamorous, but it will work, and you don't have to go through the hassle of examining raw network data (as interesting as that sounds ;^)

PCS