EvmFilterCreate(3)					     Library Functions Manual						EvmFilterCreate(3)

NAME

       EvmFilterCreate(),  EvmFilterDestroy(),	EvmFilterIsFile(),  EvmFilterReadFile(),  EvmFilterSet(), EvmFilterTest() - event filter evaluator
       routines

SYNOPSIS

   Library
       EVM Support Library

   Parameters
       filter_evaluator For filter_evaluator is the return handle of an established filter evaluator.

			For filter_evaluator , identifies the filter evaluator that uses the filter_string in subsequent matches.

			For filter_evaluator identifies the filter evaluator that compares the supplied event with the filter string.

			For filter_evaluator identifies the filter evaluator to be destroyed.

       filter_string	The filter string used by the filter evaluator in subsequent matches.  See the EvmFilter(5) manpage for the syntax.

       event		The event to be compared with the filter string currently associated with the filter evaluator.

       matchFlag	The result obtained when the supplied event is compared with the filter string currently associated with the filter evalu-
			ator.  Possible return values are as follows:

			The event matches the
				    filter_string.

			The event does not match the
				    filter_string.

DESCRIPTION

       The filter evaluation routines check whether an event matches a given event filter.  These functions are useful to clients that pass a com-
       plex filter to the EVM daemon.  Then the clients test incoming events against subcomponents of the  filter  to  determine  the  appropriate
       action.

       The routine establishes an instance of a filter evaluator, returning a handle in filter_evaluator.

       The routine passes a filter_string to the filter_evaluator for subsequent matches.

       The  routine  compares the supplied event with the filter_string currently associated with the filter_evaluator.  The result is returned in
       matchFlag.  Possible return values are as follows:

	      The event matches the
			  filter_string.

	      The event does not match the
			  filter_string.

       The indirect filter syntax, is supported by the and routines.  Programs which support indirect filters may use to determine whether a user-
       supplied filter string is indirect.  If so, then use to expand the file to a regular filter string.

       returns if the supplied filter_string uses indirect filter notation, and returns otherwise.

       interprets  the supplied filter_string, and attempts to open and read the referenced file.  returns a pointer to heap space memory contain-
       ing the expanded filter string.	The caller is responsible for freeing the memory when it is no longer needed.	NULL  is  returned  if	an
       error occurs while reading the file.  Note that does not attempt to validate the filter string contained in the file.

       The routine destroys the filter_evaluator, freeing all associated resources.

RETURN VALUE

       The operation completed without error.

       A filter string that is syntactically invalid passed to the filter evaluator.

       One of the arguments to the function is invalid.

       A value in a structure member is invalid.

       An operation failed because an attempt to acquire heap memory failed.

       An attempt was made to use a filter evaluator without first calling
	      which provides an initial filter string.

       An attempt to read a filter file failed.

ERRORS

       The value of is not set.

SEE ALSO

   Event Management
       EVM(5).

   EVM Events
       EvmEvent(5).

   Event Filter
       EvmFilter(5).

																EvmFilterCreate(3)