How to find free port

To: kernelnewbies@xxxxxxxxxxxx
Subject: How to find free port
From: "Rajath N R" <rajathnr@xxxxxxxxx>
Date: Tue, 6 Mar 2007 12:40:31 +0530
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Hi all,

How to find the available port numbers?

i.e logic for find the port status,whether the port number is connected,busy or free?

Thanks in advance.
Rajath N R