Appendix B. HTTP Reference

IN THIS APPENDIX

• What Is HTTP?

• PHP Programming Libraries for HTTP Work

• Understanding an HTTP Transaction

• HTTP Client Methods

• What Comes Back: Server Response Codes

• HTTP Headers

• Encoding

• Identifying Clients and Servers

• The "Referer"

• Fetching Content from an HTTP Source

• Media Types

• Cookies: Preserving State and a Tasty Treat

• Security and Authorization

• Client-Side Caching of HTTP Content

In this appendix we'll discuss the HTTP standard from the perspective of a PHP programmer, with a look at the functions and libraries you might use.