Log file iterator pattern

WalkDir.rb

require 'pathname'
require 'date'

class WalkDir

  def initialize (opts = {})
    # Set default handlers
    @file_pattern = opts[:file_pattern] || /^[^.]/  # no hidden files
    @dir_pattern  = opts[:dir_pattern]  || /^[^.]/  # no hidden directories
    @result       = opts[:result] || lambda { |pathname, match| return pathname, match }

    # Validate params
    @file_pattern.respond_to?('match')  || raise('invalid file_pattern')
    @dir_pattern.respond_to?('match')   || raise('invalid dir_pattern')
    @result.respond_to?('call')         || raise('invalid result')
  end

  def each (filenames)
    filenames.each do |filename|
      Pathname.new(filename).find() do |pathname|
        if pathname.file? then
          match = @file_pattern.match(pathname.basename.to_s)
          next if not match
          result = @result.call(pathname, match)
          next if not result
          yield result
        else
          Find.prune if not @dir_pattern.match(pathname.basename.to_s)
        end
      end
    end
  end

end

def date_expired? (date, daysOld)
  time = Date.strptime(date,"%Y%m%d").to_time
  delta = (Time.now - time) / (24 * 60 * 60)
  delta > daysOld
end

def recent_filename_selector (daysOld)
  filter = lambda do |pathname, match|
    date = match[1]
    return nil if date_expired?(date, daysOld)

    return pathname, date 
  end

  WalkDir.new(
    :file_pattern => /^error.log-([0-9]+)(\.gz){0,1}$/,
    :result => filter
  )
end

def recent_filename_opener (daysOld)
  filter = lambda do |pathname, match|
    date, zipped = match[1..2]
    return nil if date_expired?(date, daysOld)

    file = zipped ? IO.popen("gunzip -c -d #{pathname.to_s}") : File.open(pathname.to_s)
    return pathname, date, file
  end

  WalkDir.new(
    :file_pattern => /^error.log-([0-9]+)(\.gz){0,1}$/,
    :result => filter
  )
end

# Main
if $0 == __FILE__

  puts "* Test 0: defaults"
  WalkDir.new().each(ARGV) do |pathname, match|
    puts "  #{pathname.to_s}"
  end

  puts "* Test 1: regular expression"
  file_pattern = /error.log-([0-9]+)(\.gz){0,1}$/
  WalkDir.new(:file_pattern => file_pattern).each(ARGV) do |pathname, match|
    puts "  #{pathname.to_s} -> #{match[1]}"
  end

  puts "* Test 2: selector class for file names"
  recent_filename_selector(14).each(ARGV) do |pathname, date|
    puts "  #{pathname.to_s} -> #{date}"
  end

  puts "* Test 3: selector class for file data"
  recent_filename_opener(14).each(ARGV) do |pathname, date, file|
    puts "  #{pathname.to_s} -> #{date}"
    file.each_line { |line| puts "    #{line}" }
    file.close
  end

end

__END__