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


NAME
       Log::Log4perl::Appender::Screen - Log to STDOUT/STDERR

SYNOPSIS
           use Log::Log4perl::Appender::Screen;

           my $app = Log::Log4perl::Appender::Screen->new(
             autoflush => 1,
             stderr    => 0,
             utf8      => 1,
           );

           $file->log(message => "Log me\n");

DESCRIPTION
       This is a simple appender for writing to STDOUT or STDERR.

       The constructor new() takes an optional parameter "stderr":

       o   If set to a false value, it will log all levels to STDOUT (or, more
           accurately, whichever file handle is selected via select(), STDOUT
           by default).

       o   If set to a hash, then any "log4p_level" with a truthy value will
           dynamically use STDERR, or STDOUT otherwise.

       o   Otherwise, if a true value (the default setting is 1), messages
           will be logged to STDERR.

           # All messages/levels to STDERR
           my $app = Log::Log4perl::Appender::Screen->new(
               stderr  => 1,
           );

           # Only ERROR and FATAL to STDERR (case-sensitive)
           my $app = Log::Log4perl::Appender::Screen->new(
               stderr  => { ERROR => 1, FATAL => 1},
           );

       Design and implementation of this module has been greatly inspired by
       Dave Rolsky's "Log::Dispatch" appender framework.

       To enable printing wide utf8 characters, set the utf8 option to a true
       value:

           my $app = Log::Log4perl::Appender::Screen->new(
             stderr    => 1,
             utf8      => 1,
           );

       This will issue the necessary binmode command to the selected output
       channel (stderr/stdout).

       To enable autoflush, set the "autoflush" option to a true value:

           my $app = Log::Log4perl::Appender::Screen->new(
             autoflush => 1,
           );

       This will issue the necessary autoflush command to the selected output
       channel (stderr/stdout).

       This is required in containers, especially when the log volume is low,
       to not buffer the log messages and cause a significant delay.

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 v5.42.2                      2026-08-14               Appender::Screen(3)