A sample script that uses OptionParser and Logger. A great template to start with! Shown off at @bmoreonrails on June 14, 2011

cmd_line_script.rb

# A sample script that uses OptionParser and Logger
# http://www.ruby-doc.org/stdlib/libdoc/optparse/rdoc/classes/OptionParser.html
require 'optparse'
require 'logger'

# Defaults. This hash will hold all of the options
# parsed from the command-line by
# OptionParser.
options = {
  :verbose => false,
  :quick => false,
  :logfile => nil
}

optparse = OptionParser.new do |opts|
  # Set a banner, displayed at the top
  # of the help screen.
  opts.banner = "Usage: #{$0} [options] file1 file2 ..."

  # Define the options, and what they do
  opts.on( '-v', '--verbose', 'Output more information' ) do
    options[:verbose] = true
  end

  opts.on( '-q', '--quick', 'Perform the task quickly' ) do
    options[:quick] = true
  end

  opts.on( '-l', '--logfile FILE', 'Write log to FILE' ) do |file|
    options[:logfile] = file
  end

  opts.on( '--color COLOR', ['red','green'], 'A silly param' ) do |color|
    options[:color] = color
  end
  
  opts.on( '--flavor FLAVOR', {:sweet => :candy, :bitter => :lemon}, 'A silly param' ) do |food|
    options[:food] = food
  end

  opts.on( '--phone num', /\d{3}\-\d{4}/, 'your digits' ) do |phone|
    options[:phone] = phone
  end
end

# Parse the command-line. Remember there are two forms
# of the parse method. The 'parse' method simply parses
# ARGV, while the 'parse!' method parses ARGV and removes
# any options found there, as well as any parameters for
# the options. What's left is the list of files.
optparse.parse!

def main(options, files)
  
  # replace with your awesome code
  
  $logger.debug "Being verbose" if options[:verbose]
  $logger.debug "Being quick" if options[:quick]
  $logger.debug "Logging to file #{options[:logfile]}" if options[:logfile]
  $logger.debug "color is #{options[:color]}" if options[:color]
  $logger.debug "food is #{options[:food]}" if options[:food]
  $logger.debug "call you at #{options[:phone]}" if options[:phone]

  files.each do |f|
    $logger.debug "working on file #{f}..."
    sleep 0.5
  end
  # exit with a proper return code (0 = success, 1 = failure)
  0 # success
end

$logger = Logger.new(options[:logfile] || STDOUT)
$logger.level = Logger::DEBUG
$logger.formatter = proc do |severity, datetime, progname, msg|
  "#{datetime.strftime('%Y-%m-%d %H:%M:%S')} #{severity}: #{msg}\n"
end

exit main(options, ARGV)