Class: Net::POP3

Inherits:
Protocol
  • Object
show all
Defined in:
lib/net/pop.rb

Overview

Net::POP3

What is This Library?

This library provides functionality for retrieving email via POP3, the Post Office Protocol version 3. For details of POP3, see [RFC1939] (www.ietf.org/rfc/rfc1939.txt).

Examples

Retrieving Messages

This example retrieves messages from the server and deletes them on the server.

Messages are written to files named 'inbox/1', 'inbox/2', .… Replace 'pop.example.com' with your POP3 server address, and 'YourAccount' and 'YourPassword' with the appropriate account details.

require 'net/pop'

pop = Net::POP3.new('pop.example.com')
pop.start('YourAccount', 'YourPassword')             # (1)
if pop.mails.empty?
  puts 'No mail.'
else
  i = 0
  pop.each_mail do |m|   # or "pop.mails.each ..."   # (2)
    File.open("inbox/#{i}", 'w') do |f|
      f.write m.pop
    end
    m.delete
    i += 1
  end
  puts "#{pop.mails.size} mails popped."
end
pop.finish                                           # (3)
  1. Call Net::POP3#start and start POP session.

  2. Access messages by using POP3#each_mail and/or POP3#mails.

  3. Close POP session by calling POP3#finish or use the block form of #start.

Shortened Code

The example above is very verbose. You can shorten the code by using some utility methods. First, the block form of Net::POP3.start can be used instead of POP3.new, POP3#start and POP3#finish.

require 'net/pop'

Net::POP3.start('pop.example.com', 110,
                'YourAccount', 'YourPassword') do |pop|
  if pop.mails.empty?
    puts 'No mail.'
  else
    i = 0
    pop.each_mail do |m|   # or "pop.mails.each ..."
      File.open("inbox/#{i}", 'w') do |f|
        f.write m.pop
      end
      m.delete
      i += 1
    end
    puts "#{pop.mails.size} mails popped."
  end
end

POP3#delete_all is an alternative for #each_mail and #delete.

require 'net/pop'

Net::POP3.start('pop.example.com', 110,
                'YourAccount', 'YourPassword') do |pop|
  if pop.mails.empty?
    puts 'No mail.'
  else
    i = 1
    pop.delete_all do |m|
      File.open("inbox/#{i}", 'w') do |f|
        f.write m.pop
      end
      i += 1
    end
  end
end

And here is an even shorter example.

require 'net/pop'

i = 0
Net::POP3.delete_all('pop.example.com', 110,
                     'YourAccount', 'YourPassword') do |m|
  File.open("inbox/#{i}", 'w') do |f|
    f.write m.pop
  end
  i += 1
end

Memory Space Issues

All the examples above get each message as one big string. This example avoids this.

require 'net/pop'

i = 1
Net::POP3.delete_all('pop.example.com', 110,
                     'YourAccount', 'YourPassword') do |m|
  File.open("inbox/#{i}", 'w') do |f|
    m.pop do |chunk|    # get a message little by little.
      f.write chunk
    end
    i += 1
  end
end

Using APOP

The net/pop library supports APOP authentication. To use APOP, use the Net::APOP class instead of the Net::POP3 class. You can use the utility method, Net::POP3.APOP(). For example:

require 'net/pop'

# Use APOP authentication if $isapop == true
pop = Net::POP3.APOP($is_apop).new('apop.example.com', 110)
pop.start(YourAccount', 'YourPassword') do |pop|
  # Rest of the code is the same.
end

Fetch Only Selected Mail Using 'UIDL' POP Command

If your POP server provides UIDL functionality, you can grab only selected mails from the POP server. e.g.

def need_pop?( id )
  # determine if we need pop this mail...
end

Net::POP3.start('pop.example.com', 110,
                'Your account', 'Your password') do |pop|
  pop.mails.select { |m| need_pop?(m.unique_id) }.each do |m|
    do_something(m.pop)
  end
end

The POPMail#unique_id() method returns the unique-id of the message as a String. Normally the unique-id is a hash of the message.

Direct Known Subclasses

APOP

Constant Summary collapse

Revision =
%q$Revision: 6285 $.split[1]

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(addr, port = nil, isapop = false) ⇒ POP3

Creates a new POP3 object.

address is the hostname or ip address of your POP3 server.

The optional port is the port to connect to.

The optional isapop specifies whether this connection is going to use APOP authentication; it defaults to false.

This method does not open the TCP connection.


395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
# File 'lib/net/pop.rb', line 395

def initialize(addr, port = nil, isapop = false)
  @address = addr
  @use_ssl = POP3.use_ssl?
  @port = port || (POP3.use_ssl? ? POP3.default_pop3s_port : POP3.default_pop3_port)
  @apop = isapop
  @certs = POP3.certs
  @verify = POP3.verify
  
  @command = nil
  @socket = nil
  @started = false
  @open_timeout = 30
  @read_timeout = 60
  @debug_output = nil

  @mails = nil
  @n_mails = nil
  @n_bytes = nil
end

Instance Attribute Details

#addressObject (readonly)

The address to connect to.


469
470
471
# File 'lib/net/pop.rb', line 469

def address
  @address
end

#open_timeoutObject

Seconds to wait until a connection is opened. If the POP3 object cannot open a connection within this time, it raises a TimeoutError exception.


477
478
479
# File 'lib/net/pop.rb', line 477

def open_timeout
  @open_timeout
end

#portObject (readonly)

The port number to connect to.


472
473
474
# File 'lib/net/pop.rb', line 472

def port
  @port
end

#read_timeoutObject

Seconds to wait until reading one block (by one read(1) call). If the POP3 object cannot complete a read() within this time, it raises a TimeoutError exception.


482
483
484
# File 'lib/net/pop.rb', line 482

def read_timeout
  @read_timeout
end

Class Method Details

.APOP(isapop) ⇒ Object

Returns the APOP class if isapop is true; otherwise, returns the POP class. For example:

# Example 1
pop = Net::POP3::APOP($is_apop).new(addr, port)

# Example 2
Net::POP3::APOP($is_apop).start(addr, port) do |pop|
  ....
end

238
239
240
# File 'lib/net/pop.rb', line 238

def POP3.APOP(isapop)
  isapop ? APOP : POP3
end

.auth_only(address, port = nil, account = nil, password = nil, isapop = false) ⇒ Object

Opens a POP3 session, attempts authentication, and quits.

This method raises POPAuthenticationError if authentication fails.

Example: normal POP3

Net::POP3.auth_only('pop.example.com', 110,
                    'YourAccount', 'YourPassword')

Example: APOP

Net::POP3.auth_only('pop.example.com', 110,
                    'YourAccount', 'YourPassword', true)

305
306
307
308
309
# File 'lib/net/pop.rb', line 305

def POP3.auth_only(address, port = nil,
                    = nil, password = nil,
                   isapop = false)
  new(address, port, isapop).auth_only , password
end

.certsObject


355
356
357
# File 'lib/net/pop.rb', line 355

def POP3.certs
  @certs
end

.default_pop3_portObject

The default port for POP3 connections, port 110


210
211
212
# File 'lib/net/pop.rb', line 210

def POP3.default_pop3_port
  110
end

.default_pop3s_portObject

The default port for POP3S connections, port 995


215
216
217
# File 'lib/net/pop.rb', line 215

def POP3.default_pop3s_port
  995
end

.default_portObject

Class Parameters


205
206
207
# File 'lib/net/pop.rb', line 205

def POP3.default_port
  default_pop3_port()
end

.delete_all(address, port = nil, account = nil, password = nil, isapop = false, &block) ⇒ Object

Starts a POP3 session and deletes all messages on the server. If a block is given, each POPMail object is yielded to it before being deleted.

This method raises a POPAuthenticationError if authentication fails.

Example

Net::POP3.delete_all('pop.example.com', 110,
                     'YourAccount', 'YourPassword') do |m|
  file.write m.pop
end

283
284
285
286
287
288
289
# File 'lib/net/pop.rb', line 283

def POP3.delete_all(address, port = nil,
                     = nil, password = nil,
                    isapop = false, &block)
  start(address, port, , password, isapop) {|pop|
    pop.delete_all(&block)
  }
end

.disable_sslObject

Disable SSL for all new instances.


341
342
343
344
345
# File 'lib/net/pop.rb', line 341

def POP3.disable_ssl
  @use_ssl = nil
  @verify = nil
  @certs = nil
end

.enable_ssl(verify = OpenSSL::SSL::VERIFY_PEER, certs = nil) ⇒ Object

Enable SSL for all new instances. verify is the type of verification to do on the Server Cert; Defaults to OpenSSL::SSL::VERIFY_PEER. certs is a file or directory holding CA certs to use to verify the server cert; Defaults to nil.


334
335
336
337
338
# File 'lib/net/pop.rb', line 334

def POP3.enable_ssl(verify = OpenSSL::SSL::VERIFY_PEER, certs = nil)
  @use_ssl = true
  @verify = verify
  @certs = certs  
end

.foreach(address, port = nil, account = nil, password = nil, isapop = false, &block) ⇒ Object

Starts a POP3 session and iterates over each POPMail object, yielding it to the block. This method is equivalent to:

Net::POP3.start(address, port, , password) do |pop|
  pop.each_mail do |m|
    yield m
  end
end

This method raises a POPAuthenticationError if authentication fails.

Example

Net::POP3.foreach('pop.example.com', 110,
                  'YourAccount', 'YourPassword') do |m|
  file.write m.pop
  m.delete if $DELETE
end

262
263
264
265
266
267
268
# File 'lib/net/pop.rb', line 262

def POP3.foreach(address, port = nil,
                  = nil, password = nil,
                 isapop = false, &block)  # :yields: message
  start(address, port, , password, isapop) {|pop|
    pop.each_mail(&block)
  }
end

.socket_typeObject

:nodoc: obsolete


219
220
221
# File 'lib/net/pop.rb', line 219

def POP3.socket_type   #:nodoc: obsolete
  Net::InternetMessageIO
end

.start(address, port = nil, account = nil, password = nil, isapop = false, &block) ⇒ Object

Creates a new POP3 object and open the connection. Equivalent to

Net::POP3.new(address, port, isapop).start(, password)

If block is provided, yields the newly-opened POP3 object to it, and automatically closes it at the end of the session.

Example

Net::POP3.start(addr, port, , password) do |pop|
  pop.each_mail do |m|
    file.write m.pop
    m.delete
  end
end

379
380
381
382
383
# File 'lib/net/pop.rb', line 379

def POP3.start(address, port = nil,
                = nil, password = nil,
               isapop = false, &block)   # :yield: pop
  new(address, port, isapop).start(, password, &block)
end

.use_ssl?Boolean

Returns:

  • (Boolean)

347
348
349
# File 'lib/net/pop.rb', line 347

def POP3.use_ssl?
  @use_ssl
end

.verifyObject


351
352
353
# File 'lib/net/pop.rb', line 351

def POP3.verify
  @verify
end

Instance Method Details

#apop?Boolean

Does this instance use APOP authentication?

Returns:

  • (Boolean)

416
417
418
# File 'lib/net/pop.rb', line 416

def apop?
  @apop
end

#auth_only(account, password) ⇒ Object

Starts a pop3 session, attempts authentication, and quits. This method must not be called while POP3 session is opened. This method raises POPAuthenticationError if authentication fails.

Raises:

  • (IOError)

314
315
316
317
318
319
# File 'lib/net/pop.rb', line 314

def auth_only(, password)
  raise IOError, 'opening previously opened POP session' if started?
  start(, password) {
    ;
  }
end

#delete_allObject

Deletes all messages on the server.

If called with a block, yields each message in turn before deleting it.

Example

n = 1
pop.delete_all do |m|
  File.open("inbox/#{n}") do |f|
    f.write m.pop
  end
  n += 1
end

This method raises a POPError if an error occurs.


655
656
657
658
659
660
# File 'lib/net/pop.rb', line 655

def delete_all # :yield: message
  mails().each do |m|
    yield m if block_given?
    m.delete unless m.deleted?
  end
end

#disable_sslObject


440
441
442
443
444
# File 'lib/net/pop.rb', line 440

def disable_ssl
  @use_ssl = false
  @verify = nil
  @certs = nil
end

#each_mail(&block) ⇒ Object Also known as: each

Yields each message to the passed-in block in turn. Equivalent to:

pop3.mails.each do |popmail|
  ....
end

This method raises a POPError if an error occurs.


633
634
635
# File 'lib/net/pop.rb', line 633

def each_mail(&block)  # :yield: message
  mails().each(&block)
end

#enable_ssl(verify = OpenSSL::SSL::VERIFY_PEER, certs = nil, port = POP3.default_pop3s_port) ⇒ Object

Enables SSL for this instance. Must be called before the connection is established to have any effect. verify is the type of verification to do on the Server Cert; Defaults to OpenSSL::SSL::VERIFY_PEER. certs is a file or directory holding CA certs to use to verify the server cert; Defaults to nil. port is port to establish the SSL connection on; Defaults to 995.


432
433
434
435
436
437
438
# File 'lib/net/pop.rb', line 432

def enable_ssl(verify = OpenSSL::SSL::VERIFY_PEER, certs = nil, 
               port = POP3.default_pop3s_port)
  @use_ssl = true
  @verify = verify
  @certs = certs
  @port = port
end

#finishObject

Finishes a POP3 session and closes TCP connection.

Raises:

  • (IOError)

564
565
566
567
# File 'lib/net/pop.rb', line 564

def finish
  raise IOError, 'POP session not yet started' unless started?
  do_finish
end

#inspectObject

Provide human-readable stringification of class state.


447
448
449
# File 'lib/net/pop.rb', line 447

def inspect
  "#<#{self.class} #{@address}:#{@port} open=#{@started}>"
end

#logging(msg) ⇒ Object


680
681
682
# File 'lib/net/pop.rb', line 680

def logging(msg)
  @debug_output << msg + "\n" if @debug_output
end

#mailsObject

Returns an array of Net::POPMail objects, representing all the messages on the server. This array is renewed when the session restarts; otherwise, it is fetched from the server the first time this method is called (directly or indirectly) and cached.

This method raises a POPError if an error occurs.


611
612
613
614
615
616
617
618
619
620
621
622
623
# File 'lib/net/pop.rb', line 611

def mails
  return @mails.dup if @mails
  if n_mails() == 0
    # some popd raises error for LIST on the empty mailbox.
    @mails = []
    return []
  end

  @mails = command().list.map {|num, size|
    POPMail.new(num, size, self, command())
  }
  @mails.dup
end

#n_bytesObject

Returns the total size in bytes of all the messages on the POP server.


599
600
601
602
603
# File 'lib/net/pop.rb', line 599

def n_bytes
  return @n_bytes if @n_bytes
  @n_mails, @n_bytes = command().stat
  @n_bytes
end

#n_mailsObject

Returns the number of messages on the POP server.


592
593
594
595
596
# File 'lib/net/pop.rb', line 592

def n_mails
  return @n_mails if @n_mails
  @n_mails, @n_bytes = command().stat
  @n_mails
end

#resetObject

Resets the session. This clears all “deleted” marks from messages.

This method raises a POPError if an error occurs.


665
666
667
668
669
670
671
672
# File 'lib/net/pop.rb', line 665

def reset
  command().rset
  mails().each do |m|
    m.instance_eval {
      @deleted = false
    }
  end
end

#set_all_uidsObject

:nodoc: internal use only (called from POPMail#uidl)


674
675
676
677
678
# File 'lib/net/pop.rb', line 674

def set_all_uids   #:nodoc: internal use only (called from POPMail#uidl)
  command().uidl.each do |num, uid|
    @mails.find {|m| m.number == num }.uid = uid
  end
end

#set_debug_output(arg) ⇒ Object

WARNING: This method causes a serious security hole. Use this method only for debugging.

Set an output stream for debugging.

Example

pop = Net::POP.new(addr, port)
pop.set_debug_output $stderr
pop.start(account, passwd) do |pop|
  ....
end

464
465
466
# File 'lib/net/pop.rb', line 464

def set_debug_output(arg)
  @debug_output = arg
end

#start(account, password) ⇒ Object

Starts a POP3 session.

When called with block, gives a POP3 object to the block and closes the session after block call finishes.

This method raises a POPAuthenticationError if authentication fails.

Raises:

  • (IOError)

503
504
505
506
507
508
509
510
511
512
513
514
515
516
# File 'lib/net/pop.rb', line 503

def start(, password) # :yield: pop
  raise IOError, 'POP session already started' if @started
  if block_given?
    begin
      do_start , password
      return yield(self)
    ensure
      do_finish
    end
  else
    do_start , password
    return self
  end
end

#started?Boolean Also known as: active?

true if the POP3 session has started.

Returns:

  • (Boolean)

491
492
493
# File 'lib/net/pop.rb', line 491

def started?
  @started
end

#use_ssl?Boolean

does this instance use SSL?

Returns:

  • (Boolean)

421
422
423
# File 'lib/net/pop.rb', line 421

def use_ssl?
  @use_ssl
end