Beginning PHP 5.3

Chapter 16. PHP and the Outside World

Most of the PHP applications you've worked with in this book have limited interaction with the outside world. Usually, a Web browser requests a URL, a PHP script is run, and the script returns some HTML markup back to the browser.

However, PHP can do a lot more than simply handle browser requests and return HTML. By using various built-in PHP functions and variables, a PHP script can find out a lot of information about its environment, work with different types of content, and talk to more than just Web browsers.

In this chapter you look at some common ways that your PHP scripts can interact with the wider world:

• Date and time handling: Many PHP scripts have a need to work with the current date and time, as well as manipulate dates such as birthdays and registration dates. Because dates and times can be tricky to work with, PHP gives you a number of date and time functions to help you

• Working with HTTP headers: PHP lets you access and manipulate HTTP headers directly. This allows your script to get a lot more information from the browser, as well as perform additional functions such as URL redirection and sending non-HTML content to the browser

• Reading server information: By using the $_SERVER superglobal array, your application can extract all sorts of useful information about the Web server and the currently running script

• Sending email: PHP contains a built-in mail() function that lets you compose and send email messages from within your PHP ...