From: Josef 'Jupp' Schugt <jupp@...>
Date: 2003-05-20T08:47:35+09:00
Subject: Re: NET::POPMail: Any progress information for pop()?

Saluton!

* Minero Aoki <aamine@loveruby.net>; 2003-05-19, 13:01 UTC:
> You can use iterator style #pop.

Thanks. I was quite sure that such a possiblity did exist but simply
didn't find it.

>   Net::POP.start(host, 110, user, pass) {|pop|
>     pop.each_mail do |msg|
>       $stderr.print 'reading a message: '
>       read = 0
>       msg.pop do |chunk|
>         read += chunk.size
>         if (read * 100 / msg.size) >= 10
>           $stderr.print '.'
>           read = 0
>         end
>       end
>       $stderr.puts
>       # msg.delete
>     end
>   }

Question on delete (assuming it were not commented out):

I prefer the following approach:

begin
  msg.pop do |chunk|
    read += chunk.size
    if (read * 100 / msg.size) >= 10
      $stderr.print '.'
      read = 0
    end
  end
  $stderr.puts
rescue => e
  puts "\n#{e}"
else
  msg.delete
end

This makes explicit that no message is deleted unless fetching was
successful. I use the follwing routine to fetch a mesage from a POP
server and have procmail deliver it locally. When this has been added
to the released version of my 'popclient.rb' program I will
officially announce the program. Purpose of the program is:

 - remove messages with headers that indicate they are unwanted

 - deliver other messages (or leave them on server)

By using procmail as an external MDA it is possible to make use of an
existing procmail configuration which may make use of a spamfilter
like spamassassin, deliver different types of messages to different
mailboxes, etc.

# Deliver a message using procmail as MDA
def deliver(msg)
  read  = 0
  bar   = '|'
  iter  = 0
  mail  = []
  rubout = BS.chr * (kib(msg.size).to_s.length + 12)
  begin
    msg.all{ |chunk|
      mail.push(chunk)
      print rubout unless read == 0
      read += chunk.size
      print "#{pad(kib(read), kib(msg.size))} KiB fetched"
      $stdout.flush
    }
    origin = mail.grep(/^Sender: /)
    from = nil
    if origin.empty?
      origin = mail.grep(/^From: /)
      unless origin.empty?
        origin = RMail::Address.parse(origin[0].gsub(/^From: /, ''))[0]
        from = origin.address unless origin.nil?
      end
    else
      origin = RMail::Address.parse(origin[0].gsub(/^Sender: /, ''))[0]
      from = origin.address unless origin.nil?
    end
    from = 'MAILER-DAEMON' if from.nil?
    print '. Delivering ... '
    $stdout.flush
    mda = IO.popen("procmail -f #{from}", 'a')
    mail.each{ |line|
      mda.puts line.gsub(/\r/, '')
    }
    mda.close
    puts 'Done.'
  rescue => e
    puts "\n{e}"
  else
    msg.delete
  end
end

Gis,

Josef 'Jupp' Schugt
-- 
e-mails that do not contain plain text, are larger than 50 KiB, are
unsolicited, or contain binarys are ignored unless payment from your
side or technical reasons give rise to a non-standard treatment.
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