This document discusses how to build a PHP extension in C, including preparing the development environment, generating extension skeleton files, implementing extension functions, compiling and testing the extension. It provides an example of creating a "hello world" extension and covers more advanced topics like adding parameters, returning values, memory allocation, and avoiding memory leaks when building PHP extensions in C. The document recommends resources for further information on PHP extension development.

1. Build your own PHP Extension Hanoi PHP Day 2010 Bui Dinh Ngoc AiTi-Aptech - CAH Trường đào tạo Lập trình viên Quốc tế AiTi-Aptech

2. PHP Extension ?

3. PHP Extension You've used extensions ? php_mysql , gd , pdo , curl , ...

4. PHP Extension (Zend Engine) PHP language written in C PHP interpreter written in C too And PHP Extension must written in C Another PHP implement may be using diffrence language

5. Why and When need PHP extension ? Buildin PHP function are not enough Existing PHP extension are not enough Pure PHP function are more slow Have C lib can do this for you

6. Prepare Ubuntu Linux GNU C Compiler , build , make utils PHP 5 Dev package : sudo apt-get install php5-dev PHP source code sudo svn checkout http://svn.php.net/viewvc/php/php-src/trunk

7. PHP-Src-5.3 tree directory

8. ext_skel.sh script

9. Write Hello World Extension //Example function call <?php function hello_world () { return 'Hello World' ; } ?>

10. Run ext_skel script : sudo ./ext_skel –extname=hello

11. Result

12. phpize The phpize command is used to prepare the build environment for a PHP extension.

14. Edit header file php_hello.h

15. Insert your function to header file PHP_FUNCTION(hello); /*My function here*/

16. Edit C source file - pre declare const zend_function_entry simhash_functions[] = { PHP_FE(confirm_hello_compiled, NULL) /* For testing, remove later. */ PHP_FE( hello , NULL) {NULL, NULL, NULL} /* Must be the last line in hello_functions[] */ };

17. Implement function PHP_FUNCTION(hello) { php_printf(“Hello, world!\n”); }

18. Build - Run some script sudo ./configure sudo make ls modules -> hello.so

19. Test Deploy file hello.so Check new extension is loaded by phpinfo function You also can test using existed hello.php script in ext dir

20. Advance ! Build php function with parameter Return value Memory allocation Anti Memory leak Array String Global variable PHP.INI variable ........

21. Function with parameter function hello_add ( $a , $b ) { $sum = (int) $a + (float) $b ; return $sum ; }

22. Function with parameter PHP_FUNCTION(hello_add) { long a; double b; if ( zend_parse_parameters (ZEND_NUM_ARGS() TSRMLS_CC, &quot; ld&quot;, &a, &b ) == FAILURE) { RETURN_NULL(); } RETURN_DOUBLE(a + b); }

23. Return value bool int double resource array object Only 6 return type

24. Return value (macro) RETURN_LONG() for integer values RETURN_DOUBLE() for floating point values RETURN_BOOL() for true/false values RETURN_NULL() for null value .....

25. Memory allocation

26. Anti Memory leak In C, memory management always very hard . Wrapper functions provides you with a safety net and some helpful debugging facilities But convert existing C source can't use wrapper functions

27. Reference http://i-php.net/2010/10/t-build-extension-cho-php/ http://devzone.zend.com/article/1021 &quot;Programming PHP&quot; by Rasmus Lerdorf and Kevin