Provided by: liblog-handler-perl_0.88-1_all 
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\n");
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::Bar\z/,
}
);
$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>.