File: README — Documentation for yell (0.5.1)

Yell - Your Extensible Logging Library

Yell works and is tested with ruby 1.8.7, 1.9.x, jruby 1.8 and 1.9 mode, rubinius 1.8 and 1.9 as well as ree.

Installation

System wide:

gem install yell

Or in your Gemfile:

gem "yell"

Usage

On the basics, you can use Yell just like any other logging library with a more sophisticated message formatter.

logger = Yell.new STDOUT

logger.info "Hello World"
#=> "2012-02-29T09:30:00+01:00 [ INFO] 65784 : Hello World"
#    ^                         ^       ^       ^
#    ISO8601 Timestamp         Level   Pid     Message

The strength of Yell, however, comes when using multiple adapters. The already built-in ones are IO-based and require no further configuration. Also, there are additional ones available as separate gems. Please consult the wiki on that - they are listed there.

The standard adapters are:

:stdout : Messages will be written to STDOUT
:stderr : Messages will be written to STDERR
:file : Messages will be written to a file
:datefile : Messages will be written to a timestamped file

Here are some short examples on how to combine them:

Example: Notice messages go into `STDOUT` and error messages into `STDERR`

logger = Yell.new do |l|
  l.adapter STDOUT, :level => [:debug, :info, :warn]
  l.adapter STDERR, :level => [:error, :fatal]
end

Example: Typical production Logger

We setup a logger that starts passing messages at the :info level. Severities below :error go into the 'production.log', whereas anything higher is written into the 'error.log'.

logger = Yell.new do |l|
  l.level = :info # will only pass :info and above to the adapters

  l.adapter :datefile, 'production.log', :level => Yell.level.lte(:warn)
  l.adapter :datefile, 'error.log', :level => Yell.level.gte(:error)
end

Installation

Usage

Example: Notice messages go into STDOUT and error messages into STDERR

Example: Typical production Logger

Further Readings

Example: Notice messages go into `STDOUT` and error messages into `STDERR`