Logger

This Logger class provides a simple logging utility for Ruby applications.

Log messages are sent to stdout, stderr, a file or a string by a Logger object.

The messages will have varying levels reflecting their varying importance.

The levels, and their meanings, are:

• NONE : no output
• ERROR : an error condition
• WARN : a warning
• INFO : generic (useful) information about system operation
• DEBUG : low-level information for developers

So each message has a level, and the Logger itself has a level, which acts as a filter, so you can control the amount of information emitted from the logger without having to remove actual messages.

1. Create a default logger which logs messages to STDOUT

   log = Logger.new

2. Create a logger which logs messages to STDOUT or STDERR.

   log = Logger.new(STDOUT)

   log = Logger.new(STDERR)

3. Create a logger for the file which has the specified name.

   log = Logger.new('logfile.log')

4. Create a logger which logs messages to a string.

   log = Logger.new(STRING)

 Logger.level = NONE

 log.level = INFO

Notice the different methods being used to log messages of various levels.

Messages lower than log.level are not sent to output.

Default log.level is DEBUG. That means all messages are emitted.

 DEBUG < INFO < WARN < ERROR < NONE

1. log.error "error is #{ @code }"

2. log.warn "a warning message"

3. log.info "some informations"

4. log.debug "dev info"

Messages are provided in a string or in a block, or both.

1. Message in block.

   log.error { "Argument 'foo' not given." }

2. Message as a string.

   log.error "Argument #{ @foo } mismatch."

3. Both arguments

   log.error("Argument ") { "#{ @foo } mismatch." }

 log.close

gem install pyer-logger

Building pyer-logger gem is a rake task.

rake build