_Added in 1.9.0_

*$portfree(N,[ipaddress])*

Returns [[$true]] if the specified port number is not in use, otherwise [[$false]].

*Parameters*

table(ktable).
|*Parameter*|*Description*|
| N | The port number to check. |
| [ipaddress] | If specified, only the interface with that IP address is checked for used ports, otherwise all active interfaces are checked. An adapter name can also be used instead of an IP address. |

*Example*

<pre>
; Check if port 4242 is free.
//echo -ag Port 4242 is $iif($portfree(4242), open, not open)
</pre>