How to make a PHP extension [duplicate]

Question

I know you can technically make PHP extension just by making a PHP file and using require_once.

But would it optimize the performance if you wrote an extension in C or C++.

If so, how would you make a "hello-world" for that?

Answer 1

I know you can technically make PHP extension just by making a PHP file and using require_once.

The base of this functionality is the include statement, which includes and evaluates the specified file. Extension isn't the right term, because you are just including another PHP script file. A PHP extensions provides additional functions to the language in form of a compiled module.

But would it optimize the performance, if you wrote an extension in C or C++.

Yes, it optimizes the performance. That's why PHP extensions like CPhalcon or YAF were written.

How to make a "Hello World" PHP Extension?

I will describe how you can build a "Hello World" PHP extension in five steps.

A Debian based OS is required, because we need to fetch some tools and dependencies with apt-get.

Step 1 - Setup Build Environment / Requirements

A PHP Extension is compiled C code. We need a shell (should already be installed), an editor (your choice), a compiler (here we'll use GCC), PHP itself and PHP development dependencies for the build.

sudo apt-get install build-essential php7.0 php7.0-dev 

Step 2 - Config

We need to describe our extension and the files forming it in a basic configuration file:

File: config.m4

PHP_ARG_ENABLE(php_helloworld, Whether to enable the HelloWorldPHP extension, [ --enable-helloworld-php Enable HelloWorldPHP])  if test "$PHP_HELLOWORLD" != "no"; then     PHP_NEW_EXTENSION(php_helloworld, php_helloworld.c, $ext_shared) fi 

As you can see, the NEW_EXTENSION contains a C file: php_helloworld.c.

Step 3 - Code

Let's create the C code for our extension.

Firstly, we create a header file:

php_helloworld.h

// we define Module constants #define PHP_HELLOWORLD_EXTNAME "php_helloworld" #define PHP_HELLOWORLD_VERSION "0.0.1"  // then we declare the function to be exported PHP_FUNCTION(helloworld_php); 

Secondly, we create the source file:

php_helloworld.c

// include the PHP API itself #include <php.h> // then include the header of your extension #include "php_helloworld.h"  // register our function to the PHP API  // so that PHP knows, which functions are in this module zend_function_entry helloworld_php_functions[] = {     PHP_FE(helloworld_php, NULL)     {NULL, NULL, NULL} };  // some pieces of information about our module zend_module_entry helloworld_php_module_entry = {     STANDARD_MODULE_HEADER,     PHP_HELLOWORLD_EXTNAME,     helloworld_php_functions,     NULL,     NULL,     NULL,     NULL,     NULL,     PHP_HELLOWORLD_VERSION,     STANDARD_MODULE_PROPERTIES };  // use a macro to output additional C code, to make ext dynamically loadable ZEND_GET_MODULE(helloworld_php)  // Finally, we implement our "Hello World" function // this function will be made available to PHP // and prints to PHP stdout using printf PHP_FUNCTION(helloworld_php) {     php_printf("Hello World! (from our extension)\n"); } 

Step 4 - Build

Now, we are ready to build the extension.

First we prepare the build environment for a PHP extension:

phpize 

Then we configure the build and enable our extension:

./configure --enable-php-helloworld 

Finally, we can build it:

make sudo make install 

Step 5 - Test

To test our PHP extension, lets load the helloworld_php.so extension file and execute our function helloworld_php():

php -d extension=php_helloworld.so -r 'helloworld_php();'

Done :)

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Building on Windows

If you try to build an Windows (YIKES!), then you need to adjust the steps a bit:

Step 2 - Config

File: config.w32

ARG_ENABLE("helloworld", "helloworld support", "yes");  if (PHP_HELLOWORLD == "yes") {     EXTENSION("helloworld", "php_helloworld.c"); } 

Step 4 - Build

Use nmake instead of make.

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List of helpful resources:

• A good book on the C programming language
• https://wiki.php.net/internals/
• https://wiki.php.net/internals/extensions
• http://phpinternalsbook.com/
• https://phpinternalsbook.com/php7/build_system/building_extensions.html
• https://nikic.github.io/
• http://jpauli.github.io/
• https://github.com/php/php-src
• http://www.slideshare.net/pierrej/extending-php-7-the-basics - explains basic argument handling
• https://github.com/phplang/extension-tutorial - Materials for an Extension Writing Tutorial