asterisk users - Mar 2006 - Status of another channel from AGI

I have an AGI program with an array containing a set of ${UNIQUEID} 
variables for channels that may be active on the system. I need a way 
for the program to tell if they are or not.

It's certainly possible using the manager interface, or appropriate 
"asterisk -rx" commands, but I'd prefer to do it directly from AGI
for
performance, security, and ease of configuration.

Does anyone know a neat way of doing this?

Does anyone know a neater way using console commands to get the 
uniqueids on the system than "show channels concise", then for each
row
returned a "show channel <channel>" and parsing for uniqueid?

All systems this will run on are Asterisk 1.2.4 or higher.

-- 
Alistair Cunningham,
Integrics Ltd,
+44 20 799 39 799
sip:acunningham@integrics.com
http://integrics.com/