Class: Net::POP3

Inherits:
Protocol 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: 22002 $.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.


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# File 'lib/net/pop.rb', line 410

def initialize(addr, port = nil, isapop = false)
  @address = addr
  @ssl_params = POP3.ssl_params
  @port = port
  @apop = isapop
  
  @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.


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

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.


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

def open_timeout
  @open_timeout
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.


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# File 'lib/net/pop.rb', line 497

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

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# 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)

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# 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


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# File 'lib/net/pop.rb', line 370

def POP3.certs
  return @ssl_params[:ca_file] || @ssl_params[:ca_path]
end

.create_ssl_params(verify_or_params = {}, certs = nil) ⇒ Object


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# File 'lib/net/pop.rb', line 336

def POP3.create_ssl_params(verify_or_params = {}, certs = nil)
  begin
    params = verify_or_params.to_hash
  rescue NoMethodError
    params = {}
    params[:verify_mode] = verify_or_params
    if certs
      if File.file?(certs)
        params[:ca_file] = certs
      elsif File.directory?(certs)
        params[:ca_path] = certs
      end
    end
  end
  return params
end

.default_pop3_portObject

The default port for POP3 connections, port 110


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# 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


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

def POP3.default_pop3s_port
  995
end

.default_portObject

Class Parameters


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# 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

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# 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.


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# File 'lib/net/pop.rb', line 354

def POP3.disable_ssl
  @ssl_params = nil
end

.enable_ssl(*args) ⇒ Object

call-seq:

Net::POP.enable_ssl(params = {})

Enable SSL for all new instances. params is passed to OpenSSL::SSLContext#set_params.


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# File 'lib/net/pop.rb', line 332

def POP3.enable_ssl(*args)
  @ssl_params = create_ssl_params(*args)
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

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# 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


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

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

.ssl_paramsObject


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# File 'lib/net/pop.rb', line 358

def POP3.ssl_params
  return @ssl_params
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

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# File 'lib/net/pop.rb', line 394

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)

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# File 'lib/net/pop.rb', line 362

def POP3.use_ssl?
  return !@ssl_params.nil?
end

.verifyObject


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# File 'lib/net/pop.rb', line 366

def POP3.verify
  return @ssl_params[:verify_mode]
end

Instance Method Details

#apop?Boolean

Does this instance use APOP authentication?

Returns:

  • (Boolean)

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# File 'lib/net/pop.rb', line 429

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)

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# 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.


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# File 'lib/net/pop.rb', line 666

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

#disable_sslObject


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# File 'lib/net/pop.rb', line 455

def disable_ssl
  @ssl_params = 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.


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# File 'lib/net/pop.rb', line 644

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

#enable_ssl(verify_or_params = {}, certs = nil, port = nil) ⇒ Object

call-seq:

Net::POP#enable_ssl(params = {})

Enables SSL for this instance. Must be called before the connection is established to have any effect. params is port to establish the SSL connection on; Defaults to 995. params (except :port) is passed to OpenSSL::SSLContext#set_params.


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# File 'lib/net/pop.rb', line 445

def enable_ssl(verify_or_params = {}, certs = nil, port = nil)
  begin
    @ssl_params = verify_or_params.to_hash.dup
    @port = @ssl_params.delete(:port) || @port
  rescue NoMethodError
    @ssl_params = POP3.create_ssl_params(verify_or_params, certs)
    @port = port || @port
  end
end

#finishObject

Finishes a POP3 session and closes TCP connection.

Raises:

  • (IOError)

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# File 'lib/net/pop.rb', line 573

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

#inspectObject

Provide human-readable stringification of class state.


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# File 'lib/net/pop.rb', line 460

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

#logging(msg) ⇒ Object


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# File 'lib/net/pop.rb', line 691

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.


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# File 'lib/net/pop.rb', line 622

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.


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# File 'lib/net/pop.rb', line 610

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.


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# File 'lib/net/pop.rb', line 603

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

#portObject

The port number to connect to.


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# File 'lib/net/pop.rb', line 485

def port
  return @port || (use_ssl? ? POP3.default_pop3s_port : POP3.default_pop3_port)
end

#resetObject

Resets the session. This clears all "deleted" marks from messages.

This method raises a POPError if an error occurs.


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# File 'lib/net/pop.rb', line 676

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)


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# File 'lib/net/pop.rb', line 685

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

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

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)

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# File 'lib/net/pop.rb', line 518

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)

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# File 'lib/net/pop.rb', line 506

def started?
  @started
end

#use_ssl?Boolean

does this instance use SSL?

Returns:

  • (Boolean)

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# File 'lib/net/pop.rb', line 434

def use_ssl?
  return !@ssl_params.nil?
end