Log::Log4perl::Config - phpMan

NAME
    Log::Log4perl::Config - Log4perl configuration file syntax

DESCRIPTION
    In "Log::Log4perl", configuration files are used to describe how the
    system's loggers ought to behave.

    The format is the same as the one as used for "log4j", just with a few
    perl-specific extensions, like enabling the "Bar::Twix" syntax instead
    of insisting on the Java-specific "Bar.Twix".

    Comment lines and blank lines (all whitespace or empty) are ignored.

    Comment lines may start with arbitrary whitespace followed by one of:

    # - Common comment delimiter
    ! - Java .properties file comment delimiter accepted by log4j
    ; - Common .ini file comment delimiter

    Comments at the end of a line are not supported. So if you write

        log4perl.appender.A1.filename=error.log #in current dir

    you will find your messages in a file called "error.log #in current
    dir".

    Also, blanks between syntactical entities are ignored, it doesn't matter
    if you write

        log4perl.logger.Bar.Twix=WARN,Screen

    or

        log4perl.logger.Bar.Twix = WARN, Screen

    "Log::Log4perl" will strip the blanks while parsing your input.

    Assignments need to be on a single line. However, you can break the line
    if you want to by using a continuation character at the end of the line.
    Instead of writing

        log4perl.appender.A1.layout=Log::Log4perl::Layout::SimpleLayout

    you can break the line at any point by putting a backslash at the very
    (!) end of the line to be continued:

        log4perl.appender.A1.layout=\
            Log::Log4perl::Layout::SimpleLayout

    Watch out for trailing blanks after the backslash, which would prevent
    the line from being properly concatenated.

  Loggers
    Loggers are addressed by category:

        log4perl.logger.Bar.Twix      = WARN, Screen

    This sets all loggers under the "Bar::Twix" hierarchy on priority "WARN"
    and attaches a later-to-be-defined "Screen" appender to them. Settings
    for the root appender (which doesn't have a name) can be accomplished by
    simply omitting the name:

        log4perl.logger = FATAL, Database, Mailer

    This sets the root appender's level to "FATAL" and also attaches the
    later-to-be-defined appenders "Database" and "Mailer" to it.
    Alternatively, the root logger can be addressed as "rootLogger":

        log4perl.rootLogger = FATAL, Database, Mailer

    The additivity flag of a logger is set or cleared via the "additivity"
    keyword:

        log4perl.additivity.Bar.Twix = 0|1

    (Note the reversed order of keyword and logger name, resulting from the
    dilemma that a logger name could end in ".additivity" according to the
    log4j documentation).

  Appenders and Layouts
    Appender names used in Log4perl configuration file lines need to be
    resolved later on, in order to define the appender's properties and its
    layout. To specify properties of an appender, just use the "appender"
    keyword after the "log4perl" intro and the appender's name:

            # The Bar::Twix logger and its appender
        log4perl.logger.Bar.Twix = DEBUG, A1
        log4perl.appender.A1=Log::Log4perl::Appender::File
        log4perl.appender.A1.filename=test.log
        log4perl.appender.A1.mode=append
        log4perl.appender.A1.layout=Log::Log4perl::Layout::SimpleLayout

    This sets a priority of "DEBUG" for loggers in the "Bar::Twix" hierarchy
    and assigns the "A1" appender to it, which is later on resolved to be an
    appender of type "Log::Log4perl::Appender::File", simply appending to a
    log file. According to the "Log::Log4perl::Appender::File" manpage, the
    "filename" parameter specifies the name of the log file and the "mode"
    parameter can be set to "append" or "write" (the former will append to
    the logfile if one with the specified name already exists while the
    latter would clobber and overwrite it).

    The order of the entries in the configuration file is not important,
    "Log::Log4perl" will read in the entire file first and try to make sense
    of the lines after it knows the entire context.

    You can very well define all loggers first and then their appenders (you
    could even define your appenders first and then your loggers, but let's
    not go there):

        log4perl.logger.Bar.Twix = DEBUG, A1
        log4perl.logger.Bar.Snickers = FATAL, A2

        log4perl.appender.A1=Log::Log4perl::Appender::File
        log4perl.appender.A1.filename=test.log
        log4perl.appender.A1.mode=append
        log4perl.appender.A1.layout=Log::Log4perl::Layout::SimpleLayout

        log4perl.appender.A2=Log::Log4perl::Appender::Screen
        log4perl.appender.A2.stderr=0
        log4perl.appender.A2.layout=Log::Log4perl::Layout::PatternLayout
        log4perl.appender.A2.layout.ConversionPattern = %d %m %n

    Note that you have to specify the full path to the layout class and that
    "ConversionPattern" is the keyword to specify the printf-style
    formatting instructions.

Configuration File Cookbook
    Here's some examples of often-used Log4perl configuration files:

  Append to STDERR
        log4perl.category.Bar.Twix      = WARN, Screen
        log4perl.appender.Screen        = Log::Log4perl::Appender::Screen
        log4perl.appender.Screen.layout = \
            Log::Log4perl::Layout::PatternLayout
        log4perl.appender.Screen.layout.ConversionPattern = %d %m %n

  Append to STDOUT
        log4perl.category.Bar.Twix      = WARN, Screen
        log4perl.appender.Screen        = Log::Log4perl::Appender::Screen
        log4perl.appender.Screen.stderr = 0
        log4perl.appender.Screen.layout = \
            Log::Log4perl::Layout::PatternLayout
        log4perl.appender.Screen.layout.ConversionPattern = %d %m %n

  Append to a log file
        log4perl.logger.Bar.Twix = DEBUG, A1
        log4perl.appender.A1=Log::Log4perl::Appender::File
        log4perl.appender.A1.filename=test.log
        log4perl.appender.A1.mode=append
        log4perl.appender.A1.layout = \
            Log::Log4perl::Layout::PatternLayout
        log4perl.appender.A1.layout.ConversionPattern = %d %m %n

    Note that you could even leave out

        log4perl.appender.A1.mode=append

    and still have the logger append to the logfile by default, although the
    "Log::Log4perl::Appender::File" module does exactly the opposite. This
    is due to some nasty trickery "Log::Log4perl" performs behind the scenes
    to make sure that beginner's CGI applications don't clobber the log file
    every time they're called.

  Write a log file from scratch
    If you loathe the Log::Log4perl's append-by-default strategy, you can
    certainly override it:

        log4perl.logger.Bar.Twix = DEBUG, A1
        log4perl.appender.A1=Log::Log4perl::Appender::File
        log4perl.appender.A1.filename=test.log
        log4perl.appender.A1.mode=write
        log4perl.appender.A1.layout=Log::Log4perl::Layout::SimpleLayout

    "write" is the "mode" that has "Log::Log4perl::Appender::File"
    explicitly clobber the log file if it exists.

  Configuration files encoded in utf-8
    If your configuration file is encoded in utf-8 (which matters if you
    e.g. specify utf8-encoded appender filenames in it), then you need to
    tell Log4perl before running init():

        use Log::Log4perl::Config;
        Log::Log4perl::Config->utf( 1 );

        Log::Log4perl->init( ... );

    This makes sure Log4perl interprets utf8-encoded config files correctly.
    This setting might become the default at some point.

SEE ALSO
    Log::Log4perl::Config::PropertyConfigurator

    Log::Log4perl::Config::DOMConfigurator

    Log::Log4perl::Config::LDAPConfigurator (coming soon!)

LICENSE
    Copyright 2002-2013 by Mike Schilli <m AT perlmeister.com> and Kevin Goess
    <cpan AT goess.org>.

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

AUTHOR
    Please contribute patches to the project on Github:

        http://github.com/mschilli/log4perl

    Send bug reports or requests for enhancements to the authors via our

    MAILING LIST (questions, bug reports, suggestions/patches):
    log4perl-devel AT lists.net

    Authors (please contact them via the list above, not directly): Mike
    Schilli <m AT perlmeister.com>, Kevin Goess <cpan AT goess.org>

    Contributors (in alphabetical order): Ateeq Altaf, Cory Bennett, Jens
    Berthold, Jeremy Bopp, Hutton Davidson, Chris R. Donnelly, Matisse
    Enzer, Hugh Esco, Anthony Foiani, James FitzGibbon, Carl Franks, Dennis
    Gregorovic, Andy Grundman, Paul Harrington, Alexander Hartmaier David
    Hull, Robert Jacobson, Jason Kohles, Jeff Macdonald, Markus Peter, Brett
    Rann, Peter Rabbitson, Erik Selberg, Aaron Straup Cope, Lars Thegler,
    David Viner, Mac Yang.