Level(3) User Contributed Perl Documentation Level(3)
NAME
Log::Log4perl::Level - Predefined log levels
SYNOPSIS
use Log::Log4perl::Level;
print $ERROR, "\n";
# -- or --
use Log::Log4perl qw(:levels);
print $ERROR, "\n";
DESCRIPTION
"Log::Log4perl::Level" simply exports a predefined set of Log4perl log
levels into the caller's name space. It is used internally by
"Log::Log4perl". The following scalars are defined:
$OFF
$FATAL
$ERROR
$WARN
$INFO
$DEBUG
$TRACE
$ALL
"Log::Log4perl" also exports these constants into the caller's
namespace if you pull it in providing the ":levels" tag:
use Log::Log4perl qw(:levels);
This is the preferred way, there's usually no need to call
"Log::Log4perl::Level" explicitly.
The numerical values assigned to these constants are purely virtual,
only used by Log::Log4perl internally and can change at any time, so
please don't make any assumptions. You can test for numerical equality
by directly comparing two level values, that's ok:
if( get_logger()->level() == $DEBUG ) {
print "The logger's level is DEBUG\n";
}
But if you want to figure out which of two levels is more verbose, use
Log4perl's own comparator:
if( Log::Log4perl::Level::isGreaterOrEqual( $level1, $level2 ) ) {
print Log::Log4perl::Level::to_level( $level1 ),
" is equal or more verbose than ",
Log::Log4perl::Level::to_level( $level2 ), "\n";
}
If the caller wants to import level constants into a different
namespace, it can be provided with the "use" command:
use Log::Log4perl::Level qw(MyNameSpace);
After this $MyNameSpace::ERROR, $MyNameSpace::INFO etc. will be
defined accordingly.
Numeric levels and Strings
Level variables like $DEBUG or $WARN have numeric values that are
internal to Log4perl. Transform them to strings that can be used in a
Log4perl configuration file, use the c<to_level()> function provided by
Log::Log4perl::Level:
use Log::Log4perl qw(:easy);
use Log::Log4perl::Level;
# prints "DEBUG"
print Log::Log4perl::Level::to_level( $DEBUG ), "\n";
To perform the reverse transformation, which takes a string like
"DEBUG" and converts it into a constant like $DEBUG, use the
to_priority() function:
use Log::Log4perl qw(:easy);
use Log::Log4perl::Level;
my $numval = Log::Log4perl::Level::to_priority( "DEBUG" );
after which $numval could be used where a numerical value is required:
Log::Log4perl->easy_init( $numval );
LICENSE
Copyright 2002-2026 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 v5.34.3 2026-08-15 Level(3)
log-log4perl 1.580.0 - Generated Wed Aug 26 13:29:41 CDT 2026