Front end

The front end of the adapter is responsible for reading data from an input source and formatting it for processing by an ASL rule set. The adapter can run with one of the following front ends:

• File—Reads data from an ASCII file.

• File tail—Is designed to read the log files of long-running Domain Managers.Like the file front end, the file tail front end reads data from an ASCII file. But instead of opening the file, reading the contents and closing the file, this front end opens the file, skips to its end and waits for additional lines to be written to the file.

• Program—Reads data from the output of a command pipeline.

• Subscribe—Is used in outflow adapters. This front end connects to a Domain Manager and issues a set of subscription requests. Subsequent notifications received from the Domain Manager are formatted and delivered to the ASL rule set. There are many configuration options available with this front end. The options include selecting the subscription set to performing sophisticated smoothing and filtering of events.

  Each front end is described in a subsequent subsection. A list of options is provided in “sm_adapter front end options” on page 135. Examples of the sm_adapter command with front ends are provided in “Sample front end invocations” on page 135.