filterfish-logging

Logging by Tim Pease

• {Homepage}[http://logging.rubyforge.org/]
• {Rubyforge Project}[http://rubyforge.org/projects/logging]
• email tim dot pease at gmail dot com

== DESCRIPTION

Logging is a flexible logging library for use in Ruby programs based on the design of Java's log4j library. It features a hierarchical logging system, custom level names, multiple output destinations per log event, custom formatting, and more.

== INSTALL

sudo gem install logging

== EXAMPLE

This example configures a logger to output messages in a format similar to the core ruby Logger class. Only log messages that are warnings or higher will be logged.

require 'logging'

logger = Logging.logger(STDOUT) logger.level = :warn

logger.debug "this debug message will not be output by the logger" logger.warn "this is your last warning"

In this example, a single logger is crated that will append to STDOUT and to a file. Only log messages that are informational or higher will be logged.

require 'logging'

logger = Logging::Logger['example_logger'] logger.add_appenders( Logging::Appender.stdout, Logging::Appenders::File.new('example.log') ) logger.level = :info

logger.debug "this debug message will not be output by the logger" logger.info "just some friendly advice"

The Logging library was created to allow each class in a program to have its own configurable logger. The logging level for a particular class can be changed independently of all other loggers in the system. This example shows the recommended way of accomplishing this.

require 'logging'

Logging::Logger['FirstClass'].level = :warn Logging::Logger['SecondClass'].level = :debug

class FirstClass def initialize @log = Logging::Logger[self] end

 def some_method
   @log.debug "some method was called on #{self.inspect}"
 end

end

class SecondClass def initialize @log = Logging::Logger[self] end

 def another_method
   @log.debug "another method was called on #{self.inspect}"
 end

end

== NOTES

Although Logging is intended to supersede Log4r, it is not a one-to-one replacement for the Log4r library. Most notably is the difference in namespaces -- Logging vs. Log4r. Other differences include renaming Log4r::Outputter to Logging::Appender and renaming Log4r::Formatter to Logging::Layout. These changes were meant to bring the Logging class names more in line with the Log4j class names.

== REQUIREMENTS

Logging does not depend on any other installed libraries or gems.

== LICENSE

Ruby