SEA Technical Memorandum #0204, SEAdog 4.50; External Event Triggers
Last updated: December 8, 1988
Copyright 1988 by System Enhancement Associates, Inc.



                                SEAdog 4.50

                          External Event Triggers


Earlier versions of SEAdog introduced the concept of the "external event 
trigger" by allowing the CRASH modifier on an external event and using it 
in that fashion.  In version 4.50 we have expanded the concept to include 
several sorts of triggers, and have added "trigger thresholds".

The complete list of possible event triggers is as follows:

    Modifier       Triggered by
    ========       ============
    CRASH          Receipt of crash priority mail
    MAIL           Receipt of normal priority mail
    FILES          Receipt of attached file
    REQS           Receipt of file request or update request

For example, an external event triggered by receipt of one or more attached 
files would be defined thus:

    Event X5 all 03:00 09:00 files


Any of these modifiers can be specified at a given threshold by appending a 
dash and the threshold value.  For example, an external event triggered by 
the receipt of five or more files would be defined thus:

    Event X5 all 03:00 09:00 files-5

Multiple triggers may be placed on a given event, in which case they 
operate in parallel.  In other words, consider the following event:

    Event X5 all 03:00 09:00 files-5 mail-3 crash

This event would be triggered by the receipt of five or more files, or 
three or more normal priority messages, or one or more crash priority 
messages.  


External event triggers, in conjunction with interruptable mail events, 
allow a SEAdog system to perform "instant processing" of received mail.  
For example, consider the following:

    Event X all 06:00 18:00 mail do group in
    Event D all 06:00 18:00

This causes the SEAdog mailer to execute an event D from 06:00 to 18:00, 
interrupting it to execute a "group in" command any time mail is received.