* About this Tutorial * Hello World * Loops * Branching * Containers * Arrays * Hashes * Strings * Regular Expressions * Subroutines * Exceptions * Terminal IO * File IO * How OOP is Ruby? * Object Oriented Programming Concepts * Simple OOP in Ruby

1. Socket classes Ruby has a rich and diverse set of sockets classes. These classes range from the standard Socket class to more refined classes that focus on a particular protocol or application type. The class hierarchy of the base sockets classes is as shown below:

2. Most of the classes derive from the IO class. This means that we can use the methods of IO that are so familiar to us. The TCPSocket class supports sockets for the connection-based, reliable Transmission Control Protocol. A helper class for the creation of TCP server sockets is also available in the TCPServer class. To create a stream socket and connect it to a server, the TCPSocket class can be used. All socket classes are part of the standard library (and not part of the core classes), so to use them in your Ruby program, you must first write: require 'socket'

3. SMTP Class E-mail is still one of the most important and popular technologies used online. require 'net/smtp' user_from = "superman@world.com" user_to = "batman@world.com" msg= “How are you?" # handling exceptions begin Net::SMTP.start('localhost', 25) do |smtpclient| smtpclient.send_message(msg, user_from, user_to) end rescue Exception => e print "Exception occured: " + e end The Net::SMTP library provides functionality to send internet mail via SMTP, the Simple Mail Transfer Protocol.