* lib/logger.rb: new file. Logger, formerly called devel-logger or

Devel::Logger.

* sample/logger/*: new file.  samples of logger.rb.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@4568 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

sample/logger/app.rb

@@ -0,0 +1,46 @@
+#!/usr/bin/env ruby
+
+require 'logger'
+
+class MyApp < Logger::Application
+  def initialize(a, b, c)
+    super('MyApp')
+
+    # Set logDevice here.
+    logfile = 'app.log'
+    self.log = logfile
+    self.level = INFO
+
+    # Initialize your application...
+    @a = a
+    @b = b
+    @c = c
+  end
+
+  def run
+    @log.info  { 'Started.' }
+
+    @log.info  { "This block isn't evaled because 'debug' is not severe here." }
+    @log.debug { "Result = " << foo(0) }
+    @log.info  { "So nothing is dumped." }
+
+    @log.info  { "This block is evaled because 'info' is enough severe here." }
+    @log.info  { "Result = " << foo(0) }
+    @log.info  { "Above causes exception, so not reached here." }
+
+    @log.info  { 'Finished.' }
+  end
+
+private
+
+  def foo(var)
+    1 / var
+  end
+end
+
+status = MyApp.new(1, 2, 3).start
+
+if status != 0
+  puts 'Some error(s) occured.'
+  puts 'See "app.log".'
+end