Logger

My first serious encounter with logging was in Java. There logging is like exception handling : so complex that you actually have to build up a secondary logic beside the main flow.

So in Ruby I wanted something closer to Ruby’s way : lightweight and efficient.

Probably there are dozens of loggers out there… ( Wait a moment. Let us see how many logger repositories are on GitHub. Well, there are many. )

Usage

Just instantiate a Logger object, set it up as you need, then call its methods whenever you fill appropriate :

sample code – using Logger

require_relative 'logger'

# default logger : writes to STDOUT messages of level INFO and above
$log = Logger.new

# this will be logged
$log.log Logger::INFO, "Hello World !"

# this not as message's level is inferior to logger's level
$log.debug "Waiting for response..."

# but if we adjust the level...
$log.level = Logger::TRACE

# ... then DEBUG messages will also be logged
$log.debug "Loosing my patience..."

# or we can adjust the log line format
$log.logformat = "on %d{\%d %B at %H:%M} the %x running with PID %p generated exception %e with message %m"

# and can log unconditionally, without specifying a message level
$log << "Goodbye, cruel World :("

# after a caught exception the %e placehold will have a value
0 / 0 rescue $log << "Goodbye again :(("

# but not in the later message
$log << "That's All Folks"

# well, not really necessary if you log to STDOUT, but a good practice
$log.close

sample log

2013-12-03 16:56:59     INFO    Hello World !
2013-12-03 16:56:59     DEBUG   Waiting for response...
2013-12-03 16:56:59     DEBUG   Loosing my patience...
on 03 December at 16:56 the sample.rb running with PID 8728 generated exception  with message Goodbye, cruel World :(
on 03 December at 16:56 the sample.rb running with PID 8728 generated exception divided by 0 with message Goodbye again :((
on 03 December at 16:56 the sample.rb running with PID 8728 generated exception  with message That's All Folks

Configuration

None.

Versions

• 0.0 - April 2009
  • Initial release.
• 0.1 - December 2013
  • Adjusted to Ruby syntax changes.

Plans

• Conditional fragments, similar to WinAmp ATF : “[] means «don’t display unless metadata was found».”
• ANSI colored log levels when logging to STDOUT.
• Access instances through the Logger class to avoid using global variables.

Download

You can find the related files on GitHub in my Ruby-script repository’s logger directory :

• logger.rb - script