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Re: Excuse me, is that port taken?

by clintp (Curate)
on Aug 17, 2002 at 15:50 UTC ( #190873=note: print w/replies, xml ) Need Help??

in reply to Excuse me, is that port taken?

Two ways spring to mind. First, connect to the port yourself to see if anything is listening (untested):
use IO::Socket::INET; $sock=IO::Socket::INET->new(PeerAddr => 'machinename', PeerPort => $portnumber, Proto => 'tcp');
And if you get a "connection refused" there's probably no listener.

Another way is to bind the port yourself. If it's a low-numbered port, you'll have to be root.

use IO::Socket::INET; $sock=IO::Socket::INET->new(Listen => 1, LocalAddr => $interfaceaddres, LocalPort => $portnumber, ReuseAddr => 1, Proto => 'tcp');
If you don't get a "port already bound" error, then it's not bound.

If either of these fail, $sock will be undef and $! will have your error message.

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