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log::log4perl::filter::boolean(3) [suse man page]

Filter::Boolean(3)					User Contributed Perl Documentation					Filter::Boolean(3)

NAME

       Log::Log4perl::Filter::Boolean - Special filter to combine the results of others

SYNOPSIS

	   log4perl.logger = WARN, AppWarn, AppError

	   log4perl.filter.Match1	= sub { /let this through/ }
	   log4perl.filter.Match2	= sub { /and that, too/ }
	   log4perl.filter.MyBoolean	   = Log::Log4perl::Filter::Boolean
	   log4perl.filter.MyBoolean.logic = Match1 || Match2

	   log4perl.appender.Screen	   = Log::Dispatch::Screen
	   log4perl.appender.Screen.Filter = MyBoolean
	   log4perl.appender.Screen.layout = Log::Log4perl::Layout::SimpleLayout

DESCRIPTION

       Sometimes, it's useful to combine the output of various filters to arrive at a log/no log decision. While Log4j, Log4perl's mother ship,
       chose to implement this feature as a filter chain, similar to Linux' IP chains, Log4perl tries a different approach.

       Typically, filter results will not need to be passed along in chains but combined in a programmatic manner using boolean logic. "Log if
       this filter says 'yes' and that filter says 'no'" is a fairly common requirement but hard to implement as a chain.

       "Log::Log4perl::Filter::Boolean" is a special predefined custom filter for Log4perl which combines the results of other custom filters in
       arbitrary ways, using boolean expressions:

	   log4perl.logger = WARN, AppWarn, AppError

	   log4perl.filter.Match1	= sub { /let this through/ }
	   log4perl.filter.Match2	= sub { /and that, too/ }
	   log4perl.filter.MyBoolean	   = Log::Log4perl::Filter::Boolean
	   log4perl.filter.MyBoolean.logic = Match1 || Match2

	   log4perl.appender.Screen	   = Log::Dispatch::Screen
	   log4perl.appender.Screen.Filter = MyBoolean
	   log4perl.appender.Screen.layout = Log::Log4perl::Layout::SimpleLayout

       "Log::Log4perl::Filter::Boolean"'s boolean expressions allow for combining different appenders by name using AND (&& or &), OR (|| or |)
       and NOT (!) as logical expressions. Parentheses are used for grouping. Precedence follows standard Perl. Here's a bunch of examples:

	   Match1 && !Match2		# Match1 and not Match2
	   !(Match1 || Match2)		# Neither Match1 nor Match2
	   (Match1 && Match2) || Match3 # Both Match1 and Match2 or Match3

SEE ALSO

       Log::Log4perl::Filter, Log::Log4perl::Filter::LevelMatch, Log::Log4perl::Filter::LevelRange, Log::Log4perl::Filter::StringRange

COPYRIGHT AND LICENSE

       Copyright 2002-2009 by Mike Schilli <m@perlmeister.com> and Kevin Goess <cpan@goess.org>.

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.12.1							    2010-02-07							Filter::Boolean(3)

Check Out this Related Man Page

Appender::RRDs(3)					User Contributed Perl Documentation					 Appender::RRDs(3)

NAME

       Log::Log4perl::Appender::RRDs - Log to a RRDtool Archive

SYNOPSIS

	   use Log::Log4perl qw(get_logger);
	   use RRDs;

	   my $DB = "myrrddb.dat";

	   RRDs::create(
	     $DB, "--step=1",
	     "DS:myvalue:GAUGE:2:U:U",
	     "RRA:MAX:0.5:1:120");

	   print time(), "
";

	   Log::Log4perl->init(qq{
	     log4perl.category = INFO, RRDapp
	     log4perl.appender.RRDapp = Log::Log4perl::Appender::RRDs
	     log4perl.appender.RRDapp.dbname = $DB
	     log4perl.appender.RRDapp.layout = Log::Log4perl::Layout::PatternLayout
	     log4perl.appender.RRDapp.layout.ConversionPattern = N:%m
	   });

	   my $logger = get_logger();

	   for(10, 15, 20, 25) {
	       $logger->info($_);
	       sleep 1;
	   }

DESCRIPTION

       "Log::Log4perl::Appender::RRDs" appenders facilitate writing data to RRDtool round-robin archives via Log4perl. For documentation on RRD
       and its Perl interface "RRDs" (which comes with the distribution), check out <http://rrdtool.org>.

       Messages sent to Log4perl's RRDs appender are expected to be numerical values (ints or floats), which then are used to run a "rrdtool
       update" command on an existing round-robin database. The name of this database needs to be set in the appender's "dbname" configuration
       parameter.

       If there's more parameters you wish to pass to the "update" method, use the "rrdupd_params" configuration parameter:

	   log4perl.appender.RRDapp.rrdupd_params = --template=in:out

       To read out the round robin database later on, use "rrdtool fetch" or "rrdtool graph" for graphic displays.

COPYRIGHT AND LICENSE

       Copyright 2002-2009 by Mike Schilli <m@perlmeister.com> and Kevin Goess <cpan@goess.org>.

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.12.1							    2010-02-07							 Appender::RRDs(3)
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