Log::Handler::Examples(3pm)				User Contributed Perl Documentation			       Log::Handler::Examples(3pm)

NAME

       Log::Handler::Examples - Examples.

CREATE LOGGER

       Quite simple

	   use Log::Handler;

	   my $log = Log::Handler->new();
	   $log->add( screen => \%options );

       Create a application wide logger

	   my $log = Log::Handler->create_logger("myapp");
	   $log->add( screen => \%options );

       Once created you can use the application logger in all modules of your project:

	   package MyApp;
	   use Log::Handler;

	   my $log = Log::Handler->create_logger("myapp");
	   $log->add( screen => \%options );

	   package MyApp::Admin;
	   use Log::Handler;

	   my $log = Log::Handler->get_logger("myapp");
	   $log->info("message");

ADD OUTPUTS

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->add( dbi     => \%options );
	   $log->add( email   => \%options );
	   $log->add( file    => \%options );
	   $log->add( forward => \%options );
	   $log->add( screen  => \%options );
	   $log->add( socket  => \%options );

       This is the same like

	   $log->add( "Log::Handler::Output::DBI"     => \%options );
	   $log->add( "Log::Handler::Output::Email"   => \%options );
	   $log->add( "Log::Handler::Output::File"    => \%options );
	   $log->add( "Log::Handler::Output::Forward" => \%options );
	   $log->add( "Log::Handler::Output::Screen"  => \%options );
	   $log->add( "Log::Handler::Output::Socket"  => \%options );

RELOAD THE LOGGER

   Quite simple
	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->config(config => "logger.conf");

	   $log->reload(config => "logger.conf");

   Reload on HUP
	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->config(config => "logger.conf");

	   $SIG{HUP} = sub {
	       unless ($log->reload(config => "logger.conf")) {
		   warn "unable to reload configuration";
		   warn $log->errstr;
	       }
	   };

   Validate first
       It's possible to make a configuration check before you reload:

	   $log->validate(config => "logger.conf")
	       or warn $log->errstr;

LOG VIA DBI

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->add(
	       dbi => {
		   database   => "database",
		   driver     => "mysql",
		   host       => "127.0.0.1",
		   port       => 3306,
		   user       => "user",
		   password   => "password",
		   table      => "messages",
		   columns    => [ qw/level ctime cdate pid hostname caller progname mtime message/ ],
		   values     => [ qw/%level %time %date %pid %hostname %caller %progname %mtime %message/ ],
		   maxlevel   => "error",
		   minlevel   => "emergency"
		   newline    => 0,
		   message_pattern => "%L %T %D %P %H %C %S %t %m",
	       }
	   );

	   $log->error("log an error");

       Or with "dbname"

	   $log->add(
	       dbi => {
		   dbname     => "database",
		   driver     => "Pg",
		   host       => "127.0.0.1",
		   port       => 5432,
		   user       => "user",
		   password   => "password",
		   table      => "messages",
		   columns    => [ qw/level ctime cdate pid hostname caller progname mtime message/ ],
		   values     => [ qw/%level %time %date %pid %hostname %caller %progname %mtime %message/ ],
		   maxlevel   => "error",
		   minlevel   => "emergency"
		   newline    => 0,
		   message_pattern => "%L %T %D %P %H %C %S %t %m",
	       }
	   );

       Or with "data_source"

	   $log->add(
	       dbi => {
		   data_source => "dbi:SQLite:dbname=database.sqlite",
		   table       => "messages",
		   columns     => [ qw/level ctime cdate pid hostname caller progname mtime message/ ],
		   values      => [ qw/%level %time %date %pid %hostname %caller %progname %mtime %message/ ],
		   maxlevel    => "error",
		   minlevel    => "emergency"
		   newline     => 0,
		   message_pattern => "%L %T %D %P %H %C %S %t %m",
	       }
	   );

LOG VIA EMAIL

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->add(
	       email => {
		   host     => "mx.bar.example",
		   hello    => "EHLO my.domain.example",
		   timeout  => 30,
		   from     => "bar@foo.example",
		   to	    => "foo@bar.example",
		   subject  => "your subject",
		   buffer   => 0,
		   maxlevel => "emergency",
		   minlevel => "emergency",
		   message_pattern => '%L',
	       }
	   );

	   $log->emergency("log an emergency issue");

LOG VIA SENDMAIL

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->add(
	       sendmail => {
		   from     => "bar@foo.example",
		   to	    => "foo@bar.example",
		   subject  => "your subject",
		   maxlevel => "error",
		   minlevel => "error",
		   message_pattern => '%L',
	       }
	   );

	   $log->emergency("message");

LOG VIA FILE

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->add(
	       file => {
		   filename => "file1.log",
		   maxlevel => 7,
		   minlevel => 0
	       }
	   );

	   $log->error("log an error");

LOG VIA FORWARD

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->add(
	       forward => {
		   forward_to	   => &my_func,
		   message_pattern => [ qw/%L %T %P %H %C %S %t/ ],
		   message_layout  => "%m",
		   maxlevel	   => "info",
	       }
	   );

	   $log->info("log a information");

	   sub my_func {
	       my $params = shift;
	       print Dumper($params);
	   }

LOG VIA SCREEN

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->add(
	       screen => {
		   log_to   => "STDERR",
		   maxlevel => "info",
	       }
	   );

	   $log->info("log to the screen");

LOG VIA SOCKET

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->add(
	       socket => {
		   peeraddr => "127.0.0.1",
		   peerport => 44444,
		   maxlevel => "info",
		   die_on_errors => 0,
	       }
	   );

	   while ( 1 ) {
	       $log->info("test")
		   or warn "unable to send message: ", $log->errstr;
	       sleep 1;
	   }

   SIMPLE SOCKET SERVER (TCP)
	   use strict;
	   use warnings;
	   use IO::Socket::INET;
	   use Log::Handler::Output::File;

	   my $sock = IO::Socket::INET->new(
	       LocalAddr => "127.0.0.1",
	       LocalPort => 44444,
	       Listen	 => 2,
	   ) or die $!;

	   my $file = Log::Handler::Output::File->new(
	       filename => "file.log",
	       fileopen => 1,
	       reopen	=> 1,
	   );

	   while ( 1 ) {
	       $file->log(message => "waiting for next connection
");

	       while (my $request = $sock->accept) {
		   my $ipaddr = sprintf("%-15s", $request->peerhost);
		   while (my $message = <$request>) {
		       $file->log(message => "$ipaddr - $message");
		   }
	       }
	   }

DIFFERENT OUTPUTS

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->add(
	       file => {
		   filename => "common.log",
		   maxlevel => 6,
		   minlevel => 5,
	       }
	   );

	   $log->add(
	       file => {
		   filename => "error.log",
		   maxlevel => 4,
		   minlevel => 0,
	       }
	   );

	   $log->add(
	       email => {
		   host     => "mx.bar.example",
		   hello    => "EHLO my.domain.example",
		   timeout  => 120,
		   from     => "bar@foo.example",
		   to	    => "foo@bar.example",
		   subject  => "your subject",
		   buffer   => 0,
		   maxlevel => 0,
	       }
	   );

	   # log to common.log
	   $log->info("this is a info message");

	   # log to error.log
	   $log->warning("this is a warning");

	   # log to error.log and to foo@bar.example
	   $log->emergency("this is a emergency message");

FILTER MESSAGES

	   my $log = Log::Handler->new();

	   $log->add(
	       screen => {
		   maxlevel => 6,
		   filter_message => {
		       match1	 => "foo",
		       match2	 => "bar",
		       match3	 => "baz",
		       condition => "(match1 && match2) && !match3"
		   }
	       }
	   );

	   $log->info("foo");
	   $log->info("foo bar");
	   $log->info("foo baz");

   FILTER CALLER
       This example shows you how it's possilbe to debug messages only from a special namespace.

	   my $log = Log::Handler->new();

	   $log->add(
	       file => {
		   filename => "file1.log",
		   maxlevel => "warning",
	       }
	   );

	   $log->add(
	       screen => {
		   maxlevel => "debug",
		   message_layout => "message from %p - %m",
		   filter_caller  => qr/^Foo::Barz/,
	       }
	   );

	   $log->warning("a warning here");

	   package Foo::Bar;
	   $log->info("an info here");
	   1;

   ANOTHER FILTER
	   filter_message => "as string"

	   filter_message => qr/as regexp/

	   filter_message => sub { shift->{message} =~ /as code ref/ }

	   # or with conditions

	   filter_message => {
	       match1	 => "as string",
	       match2	 => qr/as regexp/,
	       condition => "match1 || match2",
	   }

	   filter_caller => "as string"

	   filter_caller => qr/as regexp/

CONFIG

       Examples:

	   my $log = Log::Handler->new( config => "logger.conf" );

	   # or

	   $log->add( config => "logger.conf" );

	   # or

	   $log->config( config => "logger.conf" );

       Example with Config::General.

       Script:

	   use Log::Handler;

	   my $log = Log::Handler->new();

	   $log->config( config => "logger.conf" );

       Config (logger.conf):

	   <file>
	       alias	= common
	       filename = example.log
	       maxlevel = info
	       minlevel = warn
	   </file>

	   <file>
	       alias	= error
	       filename = example-error.log
	       maxlevel = warn
	       minlevel = emergency
	   </file>

	   <file>
	       alias	= debug
	       filename = example-debug.log
	       maxlevel = debug
	       minlevel = debug
	   </file>

	   <screen>
	       log_to	= STDERR
	       dump	= 1
	       maxlevel = debug
	       minlevel = debug
	   </screen>

CHECK FOR ACTIVE LEVELS

       It can be very useful if you want to check if a level is active.

	   use Log::Handler;
	   use Data::Dumper;

	   my $log = Log::Handler->new();

	   $log->add(
	       file => {
		   filename   => "file1.log",
		   maxlevel   => 4,
	       }
	   );

	   my %hash = (foo => 1, bar => 2);

       Now you want to dump the hash, but not in any case.

	   if ( $log->is_debug ) {
	       my $dump = Dumper(\%hash);
	       $log->debug($dump);
	   }

       This would dump the hash only if the level debug is active.

AUTHOR

       Jonny Schulz <jschulz.cpan(at)bloonix.de>.

perl v5.14.2							    2012-11-21					       Log::Handler::Examples(3pm)