The alert functions notify network service programs and applications of network events. An event is a particular instance of a process or state of hardware as defined by an application. The alert functions allow applications to indicate when predefined events occur.
Other programs, network services, or internal network components use the NetAlertRaise function to raise an alert, notifying various applications or users when a particular type of event occurs. The Alert category functions, datatypes, structures, and constants are defined in the LMCONS.H, LMERR.H, and LMALERT.H header files. A source program can gain access to these definitions by defining the constants INCL_NETERRORS and INCL_NETALERT, and by including the header file LM.H.
The LMALERT.H include file defines the following classes of events for which alerts are sent out:
·A network event requiring administrative assistance
·An entry is added to an error log file
·A user or application receives a broadcast message
·A print job completes
·A user accesses or uses certain applications or resources
You can define other classes of alerts for network applications as needed. For example, an application on a server routinely writes large amounts of data to a disk drive, running the risk of filling the disk. In this case, you might want the event ``no free disk space'' to trigger an alert that notifies the application to pause or terminate the process that is filling the disk.
An application or network service program, also known as a client, registers a request to be notified of an event (or class of events) by calling the NetAlertStart function. You can register the client for several types of events by calling the NetAlertStart function multiple times. Each registration adds an entry to an alert table. An application or network service program receives alert messages through the use of a mailslot (registered as \mailslot\name). If a program requires detailed information about an event, register it as a mailslot.
You can register an application or network service program for one type of event, or for several types, by calling the NetAlertStart function multiple times. For a registered application or network service program, use the NetAlertStop function to remove that application or network service program entry from the alert table for the particular class of event.
The alert functions are:
The NetAlertRaise function is used to indicate that an event has occurred.
The fixed-length header contains the standard alert structure, STD_ALERT.
Additional information is included in the following structures:
ADMIN_OTHER_INFO
ERRLOG_OTHER_INFO
PRINT_OTHER_INFO
USER_OTHER_INFO