I'm trying to find the best way to check if the FTPeek plugin (v1.6.1) is registered already, otherwise my script will register it.

Looking at the demo file it checks for:

Position( FTPeek_LicenseInfo; "*UNLICENSED*"; 1; 1 ) > 0

however this appears to not work as an unregistered plugin returns:

360Works FTPeek v1.61

Major Version: 1

Type: Demo version

Registered To: null

Expires on: May 9, 2012 12:59:35 PM

I'm presuming I can simply check for "Registered To: null" unless there's other options I need to check for?

What is the performance hit if the script just registers the plug-in every time without registering?

You could also check for "Demo version" as that is what indicates the plugin has not been registered and is running in Demo mode.