The netstat command will show you the status of your network connections

netstat -nat

Will print out a list of all open TCP connections with ports (on Linux, check your local manpage if you're running a different *NIX, netstat tends to have subtly different syntax on the different variants). Since you're only communicating on the local host you'll likely only be interested in communications on 127.0.0.1

netstat -nlt

will print out a list of sockets your machine is listening on (and which are therefore blocked). For Linux you can also add "-p" to give you the processes listening on these sockets (if you're root).

BTW, if you're expecting to want to reuse the same port for a different process a lot, you should set SO_REUSEADDR when opening the socket for listening.

Update: Check out Net::Netstat::Wrapper for a Perl interface to netstat


There are ten types of people: those that understand binary and those that don't.

In reply to Re: Checking if a port is allready used by tirwhan
in thread Checking if a port is allready used by Outaspace

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.