Chapter 16. Internet Services
Before there was HTTP, there was FTP, IMAP, POP3, and a whole alphabet soup of other protocols. Many people quickly embraced web browsers because the browser provided an integrated program that let them check their email, transfer files, and view documents without worrying about the details surrounding the underlying means of communication. PHP provides functions, both natively and through PEAR, to use these other protocols. With them, you can use PHP to create web frontend applications that perform all sorts of network-enabled tasks, such as looking up domain names or sending web-based email. Although PHP simplifies these jobs, it is important to understand the strengths and limitations of each protocol.
Sending Mail to Reading Mail with IMAP or POP3 cover the most popular feature of all: email. Sending Mail shows how to send basic email messages. Sending MIME Mail describes MIME-encoded email, which enables you to send plain text and HTML-formatted messages. The IMAP and POP3 protocols, which are used to read mailboxes, are discussed in Reading Mail with IMAP or POP3.
Getting and Putting Files with FTP covers how to exchange files using FTP (file transfer protocol), which is a method for sending and receiving files across the Internet. FTP servers can require users to log in with a password or allow anonymous usage.