【正文】 I, which had more functionality. PHP/FI included a larger implementation for the C programming language and could municate with databases, enabling the building of simple, dynamic web applications. Lerdorf released PHP publicly on June 8, 1995 to accelerate bug location and improve the code. This release was named PHP version 2 and already had the basic functionality that PHP has today. This included Perllike variables, form handling, and the ability to embed HTML. The syntax was similar to Perl but was more limited, simpler, and less consistent. Zeev Suraski and Andi Gutmans, two Israeli developers at the Technion IIT, rewrote the parser in 1997 and formed the base of PHP 3, changing the language39。s name to the recursive initialism PHP:Hypertext Preprocessor. The development team officially released PHP/FI 2 in November 1997 after months of beta testing. Afterwards, public testing of PHP 3 began, and the official launch came in June 1998. Suraski and Gutmans then started a new rewrite of PHP39。s core, producing the Zend Engine in 1999. They also founded Zend Technologies in Ramat Gan, Israel. On May 22, 2021, PHP 4, powered by the Zend Engine , was released. On July 13, 2021, PHP 5 was released, powered by the new Zend Engine II. PHP 5 included new features such as improved support for objectoriented programming, the PHP Data Objects extension (which defines a lightweight and consistent interface for accessing databases), and numerous performance enhancements. The most recent update released by 3 The PHP Group is for the older PHP version 4 code branch. As of August, 2021 this branch is up to version . PHP 4 is no longer under development nor will any security updates be released. In 2021, PHP 5 became the only stable version under development. Late static binding has been missing from PHP and will be added in version . PHP 6 is under development alongside PHP 5. Major changes include the removal of register_globals, magic quotes, and safe mode. The reason for the removals was because register_globals had given way to security holes, and magic quotes had an unpredictable nature, and was best avoided. Instead, to escape characters, magic quotes may be substituted with the addslashes() function, or more appropriately an escape mechanism specific to the database vendor itself like mysql_real_escape_string() for MySQL. How PHP Works PHP is generally used as a serverside scripting language。 it is especially wellsuited for creating dynamic web pages. The scripting language features integrated support for interfacing with databases such as MySQL, which makes it a prime candidate for building all manner of web applications, from simple personal web sites to plex enterpriselevel applications. Unlike HTML, which is parsed by a browser when a page loads, PHP is preprocessed by the machine that serves the document (this machine is referred to as a server). All PHP code contained with the document is processed by the server before the document is sent to the visitor’s browser. PHP is a scripted language, which is another great advantage for PHP programmers. Many programming languages require that you pile files into machine code before they can be run, which is a timeconsuming process. Bypassing the need to pile means you’re able to edit and test code much more quickly. Because PHP is a serverside language, running PHP scripts on your local machine requires installing a server on your local machine, as well. The examples in this book rely on the Apache web server to deliver your web pages. Serving web pages with Apache HTTP Server is the most popular web server on the web。 it hosts nearly half of all web si