Problem with cups

["Dave Bartmess" <dingodave@edingo.net>]

I'm trying to get CUPS working on this machine, and it seems like
there's another port connecting to 631, which stops cups dead... The
entry from the /var/log/cups/error_log is below.

How can I check which ports are in use? I know there's a command for it,
but I can't seem to find it anywhere online.

Thanks!

I [16/Sep/2002:12:37:47 -0600] Listening to 0:80
I [16/Sep/2002:12:37:47 -0600] Listening to 0:631
I [16/Sep/2002:12:37:47 -0600] Listening to a000003:631
I [16/Sep/2002:12:37:47 -0600] Listening to a000003:80
I [16/Sep/2002:12:37:47 -0600] Listening to a000003:631
I [16/Sep/2002:12:37:47 -0600] Configured for up to 100 clients.
I [16/Sep/2002:12:37:47 -0600] LoadPPDs: Read "/etc/cups/ppds.dat", 1059
PPDs...
I [16/Sep/2002:12:37:47 -0600] LoadPPDs: No new or changed PPDs...
E [16/Sep/2002:12:38:02 -0600] StartListening: Unable to bind socket -
Address already