On Wed, Jan 30, 2013 at 3:54 PM, Mamba B. [email protected]
I personally prefer to put the “true” before the “rescue” because this
is the regular control flow. You can even change that to a one liner
def port_alive? port
(TCPServer.new(‘localhost’, port).close; true) rescue false
Port will be closed. While closing if an exception occurs, it
returns false. Else true.
But note that your system may have multiple network addresses and this
check verifies just one. The same port could be occupied on another
Plus, if you do the check to decide whether to start a server on that
port the port may be closed the very moment you try to open the port
“for real”. In these situations it’s usually better to just open the
port and deal with the error because you need to do that anyway.