Badger::Log
- NAME
- SYNOPSIS
- DESCRIPTION
- CONFIGURATION OPTIONS
- debug
- info
- warn
- error
- fatal
- format
- system
- strftime
- METHODS
- new(\%options)
- debug($message)
- info($message)
- warn($message)
- error($message)
- fatal($message)
- debug_msg($format,@args)
- info_msg($format,@args)
- warn_msg($format,@args)
- error_msg($format,@args)
- fatal_msg($format,@args)
- log($level, $message)
- level($level, $action)
- enable($level)
- disable($level)
- INTERNAL METHODS
- _error_msg($format,@args)
- _fatal_msg($format,@args)
- AUTHOR
- COPYRIGHT
- SEE ALSO
use Badger::Log; my $log = Badger::Log->new({ debug => 0, # ignore debug messages info => 1, # print info messages warn => \@warn, # add warnings to list error => $log2, # delegate errors to $log2 fatal => sub { # custom fatal error handler my $message = shift; print "FATAL ERROR: $message\n"; }, }); $log->debug('a debug message'); $log->info('an info message'); $log->warn('a warning message'); $log->error('an error message'); $log->fatal('a fatal error message');
This module defines a simple base class module for logging messages generated by an application. It is intentionally very simple in design, providing the bare minimum in functionality with the possibility for extension by subclassing.
It offers little, if anything, over the many other fine logging modules available from CPAN. It exists to provide a basic logging facility that integrates cleanly with, and can be bundled up with the other Badger modules so that you've got something that works "out of the box".
There are five message categories:
- debug
A debugging message.
- info
A message providing some general information.
- warn
A warning message.
- error
An error message.
- fatal
A fatal error message.
Flag to indicate if debugging messages should be generated and output.
The default value is 0
. It can be set to 1
to
enable debugging messages or to one of the other reference values
described in the documentation for the new()
method.
Flag to indicate if information messages should be generated and output.
The default value is 0
. It can be set to 1
to
enable information messages or to one of the other reference values
described in the documentation for the new()
method.
Flag to indicate if warning messages should be generated and output. The
default value is 1
. It can be set to 0
to
disable warning messages or to one of the other reference values
described in the documentation for the new()
method.
Flag to indicate if error messages should be generated and output. The
default value is 1
. It can be set to 0
to
disable error messages or to one of the other reference values described
in the documentation for the new() method.
Flag to indicate if fatal messages should be generated and output. The
default value is 1
. It can be set to 0
to
disable fatal error messages (at your own peril) or to one of the other
reference values described in the documentation for the new() method.
This option can be used to define a different log message format.
my $log = Badger::Log->new( format => '[<level>] [<time>] <message>', );
The default message format is:
[<time>] [<system>] [<level>] <message>
The <XXX>
snippets are replaced with their equivalent
values:
time The current local time system A system identifier, defaults to 'Badger' level The message level: debug, info, warn, error or fatal message The log message itself
The format can also be set using a $FORMAT
package variable
in a subclass of Badger::Log
.
package Your::Log::Module; use base 'Badger::Log'; our $FORMAT = '[<level>] [<time>] <message>'; 1;
A system identifier which is inserted into each message via the
<system>
snippet. See format for further information. The default
value is Badger
.
my $log = Badger::Log->new( system => 'MyApp', );
The system identifier can also be set using a $SYSTEM
package variable in a subclass of Badger::Log
.
package Your::Log::Module; use base 'Badger::Log'; our $SYSTEM = 'MyApp'; 1;
This option can be used to set the format for the timestamp added to
messages via the via the <time<gt
> snippet.
my $log = Badger::Log->new( strftime => '%a %b %d %Y', );
The format string is passed to the format() method of Badger::Timestamp.
Constructor method which creates a new Badger::Log
object.
It accepts a list of named parameters or reference to hash of
configuration options that define how each message type should be
handled.
my $log = Badger::Log->new({ debug => 0, # ignore debug messages info => 1, # print info messages warn => \@warn, # add warnings to list error => $log2, # delegate errors to $log2 fatal => sub { # custom fatal error handler my $message = shift; print "FATAL ERROR: $message\n"; }, });
Each message type can be set to 0
to ignore messages or
1
to have them printed to STDERR
. They can also
be set to reference a list (the message is appended to the list), a
subroutine (which is called, passing the message as an argument), or any
object which implements a log() method (to
which the message is delegated).
Generate an information message.
$log->info('The pod doors are closed');
Generate an error message.
$log->error("I'm sorry Dave, I can't do that');
Generate a fatal error message.
$log->fatal('HAL is dead, aborting mission');
This method uses the message() method inherited from Badger::Base to generate a debugging message from the arguments provided. To use this facility you first need to create your own logging subclass which defines the message formats that you want to use.
package Your::Log; use base 'Badger::Log'; our $MESSAGES = { denied => "Denied attempt by %s to %s", }; 1;
You can now use your logging module like so:
use Your::Log; my $log = Your::Log->new; $log->debug_msg( denied => 'Arthur', 'make tea' );
The log message generated will look something like this:
# TODO
This method uses the message() method inherited from Badger::Base to generate an info message from the arguments provided. See debug_msg() for an example of using message formats.
This method uses the message() method inherited from Badger::Base to generate a warning message from the arguments provided. See debug_msg() for an example of using message formats.
This method uses the message() method inherited from Badger::Base to generate an error message from the arguments provided. See debug_msg() for an example of using message formats.
This method uses the message() method inherited from Badger::Base to generate a fatal error message from the arguments provided. See debug_msg() for an example of using message formats.
This is the general-purpose logging method that the above methods call.
$log->log( info => 'star child is here' );
This method is used to get or set the action for a particular level. When called with a single argument, it returns the current action for that level.
my $debug = $log->level('debug');
When called with two arguments it sets the action for the log level to the second argument.
$log->level( debug => 0 ); # disable $log->level( info => 1 ); # enable $log->level( warn => $list ); # push to list $log->level( error => $code ); # call code $log->level( fatal => $log2 ); # delegate to another log
This method can be used to enable one or more logging levels.
$log->enable('debug', 'info', 'warn');
The error_msg() method redefines the error_msg()
method inherited from Badger::Base (which can be considered both a bug and a feature).
The internal _error_msg()
method effectively bypasses the
new method and performs the same functionality as the base class method,
in throwing an error as an exception.
As per _error_msg(), this method provides access to the functionality of the fatal_msg() method in Badger::Base.
Andy Wardley http://wardley.org/
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.