what is PHP
PHP is a scripting language originally designed for producing dynamic web pages. It has evolved to include a command line interface capability and can be used in standalone graphical applications.
While PHP was originally created by Rasmus Lerdorf in 1995, the main implementation of PHP is now produced by The PHP Group and serves as the de facto standard for PHP as there is no formal specification.PHP is free software released under the PHP License, however it is incompatible with the GNU General Public License (GPL), due to restrictions on the usage of the term PHP.
PHP is a widely-used general-purpose scripting language that is especially suited for web development and can be embedded into HTML. It generally runs on a web server, taking PHP code as its input and creating web pages as output. It can be deployed on most web servers and on almost every operating system and platform free of charge. PHP is installed on more than 20 million websites and 1 million web servers.
History of PHP
PHP originally stood for Personal Home Page. It began in 1994 as a set of Common Gateway Interface binaries written in the C programming language by the Danish/Greenlandic programmer Rasmus Lerdorf. Lerdorf initially created these Personal Home Page Tools to replace a small set of Perl scripts he had been using to maintain his personal homepage. The tools were used to perform tasks such as displaying his résumé and recording how much traffic his page was receiving. He combined these binaries with his Form Interpreter to create PHP/FI, which had more functionality. PHP/FI included a larger implementation for the C programming language and could communicate 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 Perl-like 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 language'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 PHP's core, producing the Zend Engine in 1999. They also founded Zend Technologies in Ramat Gan, Israel.
On May 22, 2000, PHP 4, powered by the Zend Engine 1.0, was released. On July 13, 2004, PHP 5 was released, powered by the new Zend Engine II. PHP 5 included new features such as improved support for object-oriented 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 The PHP Group is for the older PHP version 4 code branch. As of August, 2008 this branch is up to version 4.4.9. PHP 4 is no longer under development nor will any security updates be released.
In 2008, PHP 5 became the only stable version under development. Late static binding has been missing from PHP and will be added in version 5.3. PHP 6 is under development alongside PHP 5. Major changes include the removal of register_globals,[14] 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.
PHP does not have complete native support for Unicode or multibyte strings;Unicode support will be included in PHP 6. Many high profile open source projects ceased to support PHP 4 in new code as of February 5, 2008, due to the GoPHP5 initiative, provided by a consortium of PHP developers promoting the transition from PHP 4 to PHP 5.
It runs in both 32-bit and 64-bit environments, but on Windows the only official distribution is 32-bit, requiring Windows 32-bit compatibility mode to be enabled while using IIS in a 64-bit Windows environment. There is a third-party distribution available for 64-bit Windows.
Release History
| Meaning | |
|---|---|
| Red | Old release; not supported |
| Yellow | Old release; still supported |
| Green | Current release |
| Blue | Future release |
| Major Version | Minor Version | Release date | Notes |
|---|---|---|---|
| 1.0 | 1.0.0 | 1995-06-08 | Officially called "Personal Home Page Tools (PHP Tools)". This is the first use of the name "PHP". |
| 2.0 | 2.0.0 | 1996-04-16 | Considered by its creator as the "fastest and simplest tool" for creating dynamic web pages. |
| 3.0 | 3.0.0 | 1998-06-06 | Development moves from one person to multiple developers. Zeev Suraski and Andi Gutmans rewrite the base for this version. |
| 4.0 | 4.0.0 | 2000-05-22 | Added more advanced two-stage parse/execute tag-parsing system called the Zend engine. |
| 4.1.0 | 2001-12-10 | Introduced 'superglobals' ($_GET, $_POST, $_SESSION, etc.) | |
| 4.2.0 | 2002-04-22 | Disabled register_globals by default. Data received over the network is not inserted directly into the globalnamespace anymore, closing possible security holes in applications. | |
| 4.3.0 | 2002-12-27 | Introduced the CLI, in addition to the CGI. | |
| 4.4.0 | 2005-07-11 | Added man pages for phpize and php-config scripts. | |
| 4.4.8 | 2008-01-03 | Several security enhancements and bug fixes. Was to be the end of life release for PHP 4. Security updates only until 2008-08-08, if necessary. | |
| 4.4.9 | 2008-08-07 | More security enhancements and bug fixes. The last release of the PHP 4.4 series. | |
| 5.0 | 5.0.0 | 2004-07-13 | Zend Engine II with a new object model. |
| 5.1.0 | 2005-11-24 | Performance improvements with introduction of compiler variables in re-engineered PHP Engine. | |
| 5.2.0 | 2006-11-02 | Enabled the filter extension by default. | |
| 5.2.8 | 2008-12-08[26] | Emergent bug fix | |
| 5.2.9 | 2009-02-26 | ||
| 5.3.0 | Second Quarter of 2009[27] | Namespace support; Late static bindings, Jump label (limited goto), Closures, Native PHP archives (phar), Garbage collection, Persistent Connection with mysqli, sqlite3, Added fileinfo as a mime_magic replacement for better MIME support | |
| 6.0 | 6.0.0 | No date set | Unicode support; removal of ereg extension, 'register_globals', 'magic_quotes' and 'safe_mode'; Alternative PHP Cache |
Characteristics of PHP
- Usage
- Speed optimization
- Security
- Platform independent
Thus PHP had got succeeded in these days and even PHP is installed on more than 20 million websites and 1 million web servers.
