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Invoking Actions

Actions can be invoked each time an event occurs, or they can be dispatched once and then be passed many events. The type of action being used determines the data passing method ENS uses to inform the action of the event or events destined for it.

There are two data passing methods: using the command line or an interprocess communication (IPC). The following table explains them in detail.

Data Passing Method

Description

Action Type

Command line

All event details are passed on the command line used to dispatch the action. This method is used for actions requiring only details of the single event they were dispatched for.

Shell script, command procedure or image

IPC

All event details are passed to the action through a UNIX domain socket or OpenVMS mailbox. This method is used for actions that are to be sent multiple events.

Image

The values you give to the Action Type attribute determines the data passing method. The possible values are shown in the following table.

Action Type

Data Passing Method

Dispatch Behavior

Command procedure

Command line

One instance of the action is dispatched for each event and each userdata item.

Image

IPC

One instance of the action is dispatched for all events and all userdata items.

Image

IPC

One instance of the action is dispatched for all events and each userdata item.