An HTTP client API for Ruby.

Net::HTTP provides a rich library which can be used to build HTTP user-agents. For more details about HTTP see [RFC2616](www.ietf.org/rfc/rfc2616.txt)

Net::HTTP is designed to work closely with URI. URI::Generic#host, URI::Generic#port and URI::HTTP#request_uri are designed to work with Net::HTTP.

If you are only performing a few GET requests you should try OpenURI.

Simple Examples

All examples assume you have loaded Net::HTTP with:

require 'net/http'

This will also require 'uri' so you don't need to require it separately.

The Net::HTTP methods in the following section do not persist connections. They are not recommended if you are performing many HTTP requests.

GET

Net::HTTP.get('example.com', '/index.html') # => String

GET by URI

uri = URI('http://example.com/index.html?count=10')
Net::HTTP.get(uri) # => String

GET with Dynamic Parameters

uri = URI('http://example.com/index.html')
params = { :limit => 10, :page => 3 }
uri.query = URI.encode_www_form(params)

res = Net::HTTP.get_response(uri)
puts res.body if res.is_a?(Net::HTTPSuccess)

POST

uri = URI('http://www.example.com/search.cgi')
res = Net::HTTP.post_form(uri, 'q' => 'ruby', 'max' => '50')
puts res.body

POST with Multiple Values

uri = URI('http://www.example.com/search.cgi')
res = Net::HTTP.post_form(uri, 'q' => ['ruby', 'perl'], 'max' => '50')
puts res.body

How to use Net::HTTP

The following example code can be used as the basis of a HTTP user-agent which can perform a variety of request types using persistent connections.

uri = URI('http://example.com/some_path?query=string')

Net::HTTP.start(uri.host, uri.port) do |http|
  request = Net::HTTP::Get.new uri.request_uri

  response = http.request request # Net::HTTPResponse object
end

Net::HTTP.start immediately creates a connection to an HTTP server which is kept open for the duration of the block. The connection will remain open for multiple requests in the block if the server indicates it supports persistent connections.

The request types Net::HTTP supports are listed below in the section “HTTP Request Classes”.

If you wish to re-use a connection across multiple HTTP requests without automatically closing it you can use ::new instead of ::start. request will automatically open a connection to the server if one is not currently open. You can manually close the connection with finish.

Response Data

uri = URI('http://example.com/index.html')
res = Net::HTTP.get_response(uri)

# Headers
res['Set-Cookie']            # => String
res.get_fields('set-cookie') # => Array
res.to_hash['set-cookie']    # => Array
puts "Headers: #{res.to_hash.inspect}"

# Status
puts res.code       # => '200'
puts res.message    # => 'OK'
puts res.class.name # => 'HTTPOK'

# Body
puts res.body if res.response_body_permitted?

Following Redirection

Each Net::HTTPResponse object belongs to a class for its response code.

For example, all 2XX responses are instances of a Net::HTTPSuccess subclass, a 3XX response is an instance of a Net::HTTPRedirection subclass and a 200 response is an instance of the Net::HTTPOK class. For details of response classes, see the section “HTTP Response Classes” below.

Using a case statement you can handle various types of responses properly:

def fetch(uri_str, limit = 10)
  # You should choose a better exception.
  raise ArgumentError, 'too many HTTP redirects' if limit == 0

  response = Net::HTTP.get_response(URI(uri_str))

  case response
  when Net::HTTPSuccess then
    response
  when Net::HTTPRedirection then
    location = response['location']
    warn "redirected to #{location}"
    fetch(location, limit - 1)
  else
    response.value
  end
end

print fetch('http://www.ruby-lang.org')

POST

A POST can be made using the Net::HTTP::Post request class. This example creates a urlencoded POST body:

uri = URI('http://www.example.com/todo.cgi')
req = Net::HTTP::Post.new(uri.path)
req.set_form_data('from' => '2005-01-01', 'to' => '2005-03-31')

res = Net::HTTP.start(uri.hostname, uri.port) do |http|
  http.request(req)
end

case res
when Net::HTTPSuccess, Net::HTTPRedirection
  # OK
else
  res.value
end

At this time Net::HTTP does not support multipart/form-data. To send multipart/form-data use Net::HTTPGenericRequest#body= and Net::HTTPHeader#content_type=:

req = Net::HTTP::Post.new(uri.path)
req.body = multipart_data
req.content_type = 'multipart/form-data'

Other requests that can contain a body such as PUT can be created in the same way using the corresponding request class (Net::HTTP::Put).

Setting Headers

The following example performs a conditional GET using the If-Modified-Since header. If the files has not been modified since the time in the header a Not Modified response will be returned. See RFC 2616 section 9.3 for further details.

uri = URI('http://example.com/cached_response')
file = File.stat 'cached_response'

req = Net::HTTP::Get.new(uri.request_uri)
req['If-Modified-Since'] = file.mtime.rfc2822

res = Net::HTTP.start(uri.hostname, uri.port) {|http|
  http.request(req)
}

open 'cached_response', 'w' do |io|
  io.write res.body
end if res.is_a?(Net::HTTPSuccess)

Basic Authentication

Basic authentication is performed according to [RFC2617](www.ietf.org/rfc/rfc2617.txt)

uri = URI('http://example.com/index.html?key=value')

req = Net::HTTP::Get.new(uri.request_uri)
req.basic_auth 'user', 'pass'

res = Net::HTTP.start(uri.hostname, uri.port) {|http|
  http.request(req)
}
puts res.body

Streaming Response Bodies

By default Net::HTTP reads an entire response into memory. If you are handling large files or wish to implement a progress bar you can instead stream the body directly to an IO.

uri = URI('http://example.com/large_file')

Net::HTTP.start(uri.host, uri.port) do |http|
  request = Net::HTTP::Get.new uri.request_uri

  http.request request do |response|
    open 'large_file', 'w' do |io|
      response.read_body do |chunk|
        io.write chunk
      end
    end
  end
end

HTTPS

HTTPS is enabled for an HTTP connection by Net::HTTP#use_ssl=.

uri = URI('https://secure.example.com/some_path?query=string')

Net::HTTP.start(uri.host, uri.port,
  :use_ssl => uri.scheme == 'https').start do |http|
  request = Net::HTTP::Get.new uri.request_uri

  response = http.request request # Net::HTTPResponse object
end

In previous versions of ruby you would need to require 'net/https' to use HTTPS. This is no longer true.

Proxies

Net::HTTP::Proxy has the same methods as Net::HTTP but its instances always connect via the proxy instead of directly to the given host.

proxy_addr = 'your.proxy.host'
proxy_port = 8080

Net::HTTP::Proxy(proxy_addr, proxy_port).start('www.example.com') {|http|
  # always connect to your.proxy.addr:8080
}

Net::HTTP::Proxy returns a Net::HTTP instance when proxy_addr is nil so there is no need for conditional code.

See Net::HTTP::Proxy for further details and examples such as proxies that require a username and password.

HTTP Request Classes

Here is the HTTP request class hierarchy.

• Net::HTTPRequest

  • Net::HTTP::Get

  • Net::HTTP::Head

  • Net::HTTP::Post

  • Net::HTTP::Put

  • Net::HTTP::Proppatch

  • Net::HTTP::Lock

  • Net::HTTP::Unlock

  • Net::HTTP::Options

  • Net::HTTP::Propfind

  • Net::HTTP::Delete

  • Net::HTTP::Move

  • Net::HTTP::Copy

  • Net::HTTP::Mkcol

  • Net::HTTP::Trace

HTTP Response Classes

Here is HTTP response class hierarchy. All classes are defined in Net module and are subclasses of Net::HTTPResponse.

HTTPUnknownResponse

For unhandled HTTP extensions

HTTPInformation

1xx

HTTPContinue

100

HTTPSwitchProtocol

101

HTTPSuccess

2xx

HTTPOK

200

HTTPCreated

201

HTTPAccepted

202

HTTPNonAuthoritativeInformation

203

HTTPNoContent

204

HTTPResetContent

205

HTTPPartialContent

206

HTTPRedirection

3xx

HTTPMultipleChoice

300

HTTPMovedPermanently

301

HTTPFound

302

HTTPSeeOther

303

HTTPNotModified

304

HTTPUseProxy

305

HTTPTemporaryRedirect

307

HTTPClientError

4xx

HTTPBadRequest

400

HTTPUnauthorized

401

HTTPPaymentRequired

402

HTTPForbidden

403

HTTPNotFound

404

HTTPMethodNotAllowed

405

HTTPNotAcceptable

406

HTTPProxyAuthenticationRequired

407

HTTPRequestTimeOut

408

HTTPConflict

409

HTTPGone

410

HTTPLengthRequired

411

HTTPPreconditionFailed

412

HTTPRequestEntityTooLarge

413

HTTPRequestURITooLong

414

HTTPUnsupportedMediaType

415

HTTPRequestedRangeNotSatisfiable

416

HTTPExpectationFailed

417

HTTPServerError

5xx

HTTPInternalServerError

500

HTTPNotImplemented

501

HTTPBadGateway

502

HTTPServiceUnavailable

503

HTTPGatewayTimeOut

504

HTTPVersionNotSupported

505

There is also the Net::HTTPBadResponse exception which is raised when there is a protocol error.

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 Net::POP3#each_mail and/or Net::POP3#mails.

3. Close POP session by calling Net::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 Net::POP3.new, Net::POP3#start and Net::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

Net::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 Net::POPMail#unique_id method returns the unique-id of the message as a String. Normally the unique-id is a hash of the message.

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 Net::POP3#each_mail and/or Net::POP3#mails.

3. Close POP session by calling Net::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 Net::POP3.new, Net::POP3#start and Net::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

Net::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 Net::POPMail#unique_id method returns the unique-id of the message as a String. Normally the unique-id is a hash of the message.

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 Net::POP3#each_mail and/or Net::POP3#mails.

3. Close POP session by calling Net::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 Net::POP3.new, Net::POP3#start and Net::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

Net::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 Net::POPMail#unique_id method returns the unique-id of the message as a String. Normally the unique-id is a hash of the message.

This class is equivalent to POP3, except that it uses APOP authentication.

Net::SMTP

What is This Library?

This library provides functionality to send internet mail via SMTP, the Simple Mail Transfer Protocol. For details of SMTP itself, see [RFC2821] (www.ietf.org/rfc/rfc2821.txt).

What is This Library NOT?

This library does NOT provide functions to compose internet mails. You must create them by yourself. If you want better mail support, try RubyMail or TMail or search for alternatives in RubyGems.org or The Ruby Toolbox.

FYI: the official documentation on internet mail is: [RFC2822] (www.ietf.org/rfc/rfc2822.txt).

Examples

Sending Messages

You must open a connection to an SMTP server before sending messages. The first argument is the address of your SMTP server, and the second argument is the port number. Using Net::SMTP.start with a block is the simplest way to do this. This way, the SMTP connection is closed automatically after the block is executed.

require 'net/smtp'
Net::SMTP.start('your.smtp.server', 25) do |smtp|
  # Use the SMTP object smtp only in this block.
end

Replace 'your.smtp.server' with your SMTP server. Normally your system manager or internet provider supplies a server for you.

Then you can send messages.

msgstr = <<END_OF_MESSAGE
From: Your Name <your@mail.address>
To: Destination Address <someone@example.com>
Subject: test message
Date: Sat, 23 Jun 2001 16:26:43 +0900
Message-Id: <unique.message.id.string@example.com>

This is a test message.
END_OF_MESSAGE

require 'net/smtp'
Net::SMTP.start('your.smtp.server', 25) do |smtp|
  smtp.send_message msgstr,
                    'your@mail.address',
                    'his_address@example.com'
end

Closing the Session

You MUST close the SMTP session after sending messages, by calling the finish method:

# using SMTP#finish
smtp = Net::SMTP.start('your.smtp.server', 25)
smtp.send_message msgstr, 'from@address', 'to@address'
smtp.finish

You can also use the block form of Net::SMTP.start/SMTP#start. This closes the SMTP session automatically:

# using block form of SMTP.start
Net::SMTP.start('your.smtp.server', 25) do |smtp|
  smtp.send_message msgstr, 'from@address', 'to@address'
end

I strongly recommend this scheme. This form is simpler and more robust.

HELO domain

In almost all situations, you must provide a third argument to Net::SMTP.start/SMTP#start. This is the domain name which you are on (the host to send mail from). It is called the “HELO domain”. The SMTP server will judge whether it should send or reject the SMTP session by inspecting the HELO domain.

Net::SMTP.start('your.smtp.server', 25,
                'mail.from.domain') { |smtp| ... }

SMTP Authentication

The Net::SMTP class supports three authentication schemes; PLAIN, LOGIN and CRAM MD5. (SMTP Authentication: [RFC2554]) To use SMTP authentication, pass extra arguments to Net::SMTP.start/SMTP#start.

# PLAIN
Net::SMTP.start('your.smtp.server', 25, 'mail.from.domain',
                'Your Account', 'Your Password', :plain)
# LOGIN
Net::SMTP.start('your.smtp.server', 25, 'mail.from.domain',
                'Your Account', 'Your Password', :login)

# CRAM MD5
Net::SMTP.start('your.smtp.server', 25, 'mail.from.domain',
                'Your Account', 'Your Password', :cram_md5)