PHP and MySQL Web Development - P78: PHP and MySQL Web Development teaches the reader to develop dynamic, secure, commercial Web sites. Using the same accessible, popular teaching style of the first edition, this best-selling book has been updated to reflect the rapidly changing landscape of MySQL and PHP. | 17 Using Network and Protocol Functions In THIS CHAPTER we ll LOOK AT the network-oriented functions in PHP that enable your scripts to interact with the rest of the Internet. There s a world of resources out there and a wide variety of protocols available for using them. In this section we ll consider An overview of available protocols Sending and reading email Using other Web sites via HTTP Using network lookup functions Using FTP Using generic network communications with cURL Overview of Protocols Protocols are the rules of communication for a given situation. For example you know the protocol when meeting another person You say hello shake hands communicate for a while and then say goodbye. Computer networking protocols are similar. Like human protocols different computer protocols are used for different situations and applications. We use HTTP the Hypertext Transfer Protocol for sending and receiving Web will probably also have used FTP File Transfer Protocol for transferring files between machines on a network. There are many others. Protocols and other Internet Standards are described in documents called RFCs or Requests for Comments. These protocols are defined by the Internet Engineering Task Force IETF .The RFCs are widely available on the base source is the RFC Editor at http 358 Chapter 17 Using Network and Protocol Functions If you have problems when working with a given protocol the RFCs are the authoritative source and are often useful for troubleshooting your code. They are however very detailed and often run to hundreds of pages. Some examples of well-known RFCs are RFC2616 which describes the HTTP protocol and RFC822 which describes the format of Internet email messages. In this chapter we will look at aspects of PHP that use some of these protocols. Specifically we will talk about sending mail with SMTP reading mail with POP and IMAP connecting to other Web servers via HTTP and HTTPS and transferring
