                           CBT - Clean-up Blind TACLs
                           --------------------------


What is a 'blind TACL'?
  A TACL is considered blind, when its home terminal is gone.

How can a TACL made blind?
  By setting it in PAUSE, and stopping the dynamic TELNET window.

What is wrong with a blind TACL?
  A blind TACL sits there, waiting for a BREAK that wakes it up.  But
  because the home terminal is gone, there is no way in sending a
  BREAK.  A blind TACL wastes system resources.

How to clean-up a blind TACL
  The one and only possibility to stop a blind TACL is by sending it a
  -20 (WAKE message), or by stopping it through the STOP command.
  But this might be a task.
  The GreenHouse FreeWare tool CBT makes life much easier:
  - it displays all blind TACL processes.
  - it optionally sends a WAKE message to the blind TACL processes,
    causing them to stop.

What happens when a -20 is sent to a TACL?
  The wake message (-20) causes a paused TACL to wake up, and to
  display its prompt. In case the home terminal no longer exists,
  writing the prompt fails with an error, which causes TACL to stop.

Who can send a wake message to TACL processes?
  Normally TACL processes can be opened by everybody, and when an OPEN
  pipe exists, the WAKE message can be sent.
  The beauty of this is, that CBT does not need any privilege to
  perform its duty!

16Jan2015, CW
