UNIX USER 2002年2月号のRuby特集の第3章「実践プログラミング〜メール編」で示したサンプルコード

popls.rb

#!/usr/bin/ruby
require 'net/pop'

def rc_parse(io)
  r = []
  io.each {|line|
    line.strip!
    if /^(?:(.*)@)?(\S+)\s+(.*)$/ =~ line
      r << if $1
	     [$1, $2, $3]
	   else
	     [ENV['USER'], $2, $3]
	   end
    end
  }

  r
end

def popstat(server, port, user, pass)
  begin
    Net::APOP.start(server, port, user, pass) {|pop|
      if pop.mails.empty?
	puts "#{user}@#{server} has no mail"
      else
	i = 0
	puts "#{user}@#{server} has mails:"
	pop.each {|mail|
	  i += 1
	  if mail.size < 1024
	    puts "  #{i}: #{mail.size}b (UIDL: #{mail.uidl})"
	  else
	    puts "  #{i}: #{mail.size/1024}Kb (UIDL: #{mail.uidl})"
	  end
	}
      end
    }
  rescue SocketError
    $stderr.puts "could not find host: #{server}"
  rescue Errno::ECONNREFUSED
    $stderr.puts "could not connect to #{server}"
  rescue Net::ProtoAuthError
    $stderr.puts "could not login to #{server} by #{user}"
  end
end

def main(rc)
  begin
    io = open(File.expand_path(rc))
    rc_parse(io).each {|user, server, pass|
      popstat(server, 110, user, pass)
    }
    
  rescue Errno::ENOENT
    $stderr.puts "#{rc} does not exist."
    exit 1
  end
end

rc = '~/.poplsrc'
main(rc)