Zend Engine

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Zend Engine
Basic data

developer Zend Technologies
Publishing year 1999
Current  version 3.2
programming language C.
category PHP accelerator
License PHP license
zend.com

The Zend Engine is a compiler for the PHP scripting language and consists of a virtual machine that compiles and executes the PHP code . It is distributed as free software under the PHP license .

With Zend, the program code goes through several compilation steps up to the executable machine code. An intermediate representation is the so-called Zend opcode, a bytecode that is still platform-independent (as in Java ). The engine is built in such a way that caches can be inserted in order to minimize redundant bytecode generation and thus to make execution more efficient. In addition to the proprietary, paid product from in-house (Zend Optimizer), there are also a number of free solutions.

Etymology / origin of the word

The name "Zend" comes from the first names of the two developers of the Zend Engine, Ze ev Suraski and A nd i Gutmans . Together they started development during their student days and later founded the company Zend Technologies .

history

The Zend Engine was developed by Zeev Suraski and Andi Gutmans because they found PHP / FI 2 too weak for e-commerce. First, on June 6, 1998, version 0.5 was published together with PHP version 3. Changes compared to the PHP / FI 2 interpreter were mainly the better performance and some changes to the syntax and behavior of PHP. Version 1.0 was released on May 22nd, 2000 together with PHP 4. It supports sessions as well as basic object-oriented programming . From version 2.0, serious object-oriented programming is possible with many new functions. In version 2.1, above all, the performance has been improved, while version 2.2 also has improved memory management. From version 2.3 the Zend Engine supports namespaces , from version 3.0 the standard character set is changed to Unicode .

See also: PHP

similar products

In order to further optimize the source code, the Zend Optimizer was developed, which acts as a supplement to the Zend Engine . Furthermore, the Zend Optimizer is required for the execution of PHP source code encrypted with Zend Guard .

Remarks

The version number of the Zend Engine corresponds to the script language PHP minus 3, since version 1.0 of the Zend Engine supports PHP version 4. As of PHP 7, this rule no longer applies - ZendEngine 3.2 is used for PHP 7.2.

Web links

Individual evidence

  1. ^ Zend engine. In: PHP Internals Book. Accessed February 1, 2019 .
  2. ↑ a b Wikipedia: PHP
  3. ↑ Migration from PHP / FI 2.0 to PHP 3.0. ( Memento of February 3, 2007 in the Internet Archive ) PHP Manual
  4. ↑ Changelog for PHP 4.0.0
  5. ↑ Performance comparison PHP 4.3.1 to PHP 5.0.0 and performance comparison PHP 4.3.1 to PHP 5.1.0. ister.org
  6. ↑ PHP 5.2.0 brings security fixes and new functions - update. heise.de
  7. ↑ Namespaces
  8. ↑ PHP and Unicode: A Love at Fifth Sight . ( Memento from May 24, 2005 in the Internet Archive )