CLI logger support

log.js

/*
 * NOTE: No packages for log, logger, log4j, etc. listed in NPM.
 * Assuming no log4j-style support for node exists.
 * 
 * NOTE: Not quite true. node-log4j is a project (1m old, "compatible with node 0.4")
 * https://github.com/nomiddlename/log4js-node
 *
 * This might be suitable but because of the lack of a package or regular maintenance
 * we may have difficulty maintaining it.
 * 
 * ----
 *
 * Due to the second requirement, we cannot use console() (requires
 * "multiple loggers") and would have to instead homebrew a Logger class
 * which would use multiple node APIs (probably all stable: 3) and probably
 * distribute it as an npm package.
 * 
 * This is a time-intensive task and falls outside of the scope of
 * a side-by-side.
 */

log.py

#!/usr/bin/env python

import logging
import sys

# Changing the StreamHandler() to a FileHandler() lets us log to a file,
# there are also RotatingFileHandler() and TimedRotatingFileHandler()
#
# See also the logging cookbook for things like multiple handlers:
# http://docs.python.org/howto/logging-cookbook.html#logging-cookbook

log = logging.getLogger('stdout')
log.setLevel(logging.WARN)
handler = logging.StreamHandler(sys.stdout)
handler.setFormatter(logging.Formatter("[%(levelname)s](%(processName)s --- %(asctime)s) %(message)s"))
log.addHandler(handler)

log.warn('oops!')

log.rb

#!/usr/bin/env ruby

require 'logger'

# The second test for ruby is not required; Logger.new() takes
# a filename or IO object as part of its constructor, as well
# as log refresh/rotation options.

logger = Logger.new(STDOUT)
logger.level = Logger::WARN #warn to stdout
logger.progname = $0
logger.formatter = proc do |severity, datetime, progname, msg|
	"[%s](%s --- %s) %s\n" % [severity, progname, datetime, msg]
end

logger.warn("oops!")
logger.close()