The Hex code I guess changes each time I run the script: Net::Telnet=GLOB(0x1cf82110)

Sure it does. Net::Telnet is an object, and its methods are documented in Net::Telnet. You might be interested in the eof and timed_out methods.

The documentation also states:

If you have the IO:: libraries installed (they come standard with perl5.004 and later) then IO::Socket::INET is used as a base class, otherwise FileHandle is used.

So, it is very likely that Net::Telnet inherits some more methods from IO::Socket::INET, which inherits from IO::Socket, which inherits from IO::Handle.

Alexander