Badger::Log::File(3pm)

NAME
Badger::Log::File - writes log messages to a log file

SYNOPSIS
    use Badger::Log::File;

    my $log = Badger::Log::File->new({
        filename  => '/var/log/badger.log',
        keep_open => 1,
    });

    $log->log('a debug message');
    $log->info('an info message');
    $log->warn('a warning message');
    $log->error('an error message');
    $log->fatal('a fatal error message');

DESCRIPTION
This module is a subclass of Badger::Log that implements a simple mechanism for logging messages to a file. It uses Badger::Filesystem for all the underlying file operations.

CONFIGURATION OPTIONS
The following configuration options are available in addition to those inherited form the Badger::Log base class.

  filename
The name of the log file which you want messages appended to. Either this or the filename_format option must be provided.

  filename_format
A format which can be used to generate a filename to write messages to. This can include any of the strftime() character sequences, e.g. %Y for the four digit year, %m for a two digit month number, %d for a two digit day of the month, etc.

    my $log = Badger::Log::File->new({
        filename_format  => '/var/log/badger-%Y-%m-%d.log',
        keep_open => 1,
    });

If, like me, you find it hard to remember the strftime() character sequences, then you can use an alternate format where the elements of the date and/or time are encoded as upper case words embedded in angle brackets. e.g. "badger-<DATE>.log", or "badger-<YEAR>-<MONTH>.log".

The words that can be embedded this way, and their corresponding strftime() character sequences are:

    DATE    => '%Y-%m-%d'       # e.g. 2022-08-24
    TIME    => '%H-%M-%S'       # e.g. 13:54:07
    YEAR    => '%Y'             # e.g. 2022
    MONTH   => '%m'             # e.g. 08
    DAY     => '%d'             # e.g. 24
    HOURS   => '%H'             # e.g. 13
    MINUTES => '%M'             # e.g. 54
    SECONDS => '%S'             # e.g. 07

The module will automatically create a new logfile when the "filename_format" generates a filename that is different to any previous value.

  filesystem
An optional reference to a Badger::Filesystem object, or the name of a filesystem class having a file() method similar to that in Badger::Filesystem. This defaults to the Badger::Filesystem class.

  keep_open
A flag indicating if the log file should be kept open between calls to logging methods. The default value is 0 meaning that the file will be opened for each message and closed again afterwards. Set it to any true value to have the file kept open.

METHODS
The following methods are implemented in addition to those inherited from Badger::Log and its base classes.

  log($level,$message)
This method redefines the log() method in Badger::Log to write logging messages to the log file.

  INTERNAL METHODS

  init(\%config)
Custom initialiser method which calls the base class init_log() method followed by the init_file() method.

  init_file(\%config)
Custom initialiser method which handles the configuration and initialisation of the file-specific parts of the logger.

  expand_filename()
Expands the format defined by the "filename_format" configuration option to a filename using the current date and time.

If "filename_format" has not been specified then it returns the value of the "filename" configuration option.

  filename_changed()
Calls expand_filename() to expand any "filename_format" and compares it to the current "filename" (which may have been generated by a previous call to this method).

If they are the same then it returns "undef". Otherwise it saves the new filename to the internal "filename" value and returns it.

  file()
Returns a reference to a Badger::Filesystem::File object based on the "filename" which can either be defined as a static configuration option or will be generated by the expand_filename() method from the "filename_format" configuration option.

  filehandle()
Returns a filehandle for the current logfile. If the filename has changed since the last call this method (determined by calling filename_changed()) then any existing filehandle is closed (by calling release()) and the new file is opened to return a new filehandle (by calling acquire()).

  acquire()
This method acquires a file handle (an IO::File object) for the specified filename, opened ready for appending log messages.

  release()
The method releases a previously acquired file handle. i.e. it closes the log file.

AUTHOR
Andy Wardley <http://wardley.org/>

COPYRIGHT
Copyright (C) 2005-2022 Andy Wardley. All Rights Reserved.

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

SEE ALSO
Badger::Log