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PHP Extension ?

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

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

Why and When need PHP extension ? 1.Buildin PHP function are not enough 2.Existing PHP extension are not enough 3.Pure PHP function are more slow 4.Have C lib can do this for you

Prepare 1.Ubuntu Linux 2.GNU C Compiler, build, make utils 3. PHP 5 Dev package : sudo apt-get install php5-dev 4.PHP source code o sudo svn checkout src/trunk o

PHP-Src-5.3 tree directory

ext_skel.sh script

Write Hello World Extension //Example function call

1.Run ext_skel script : sudo./ext_skel –extname=hello 2.

Result

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

Edit header file php_hello.h

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

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[] */ };

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

Build - Run some script 1.sudo./configure 2.sudo make 3.ls modules -> hello.so

Test 1.Deploy file hello.so 2.Check new extension is loaded by phpinfo function 3.You also can test using existed hello.php script in ext dir

Advance ! 1.Build php function with parameter 2.Return value 3.Memory allocation 4.Anti Memory leak 5.Array 6.String 7.Global variable 8.PHP.INI variable

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

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

Return value 1.bool 2.int 3.double 4.resource 5.array 6.object Only 6 return type

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.....

Memory allocation

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

Reference "Programming PHP" by Rasmus Lerdorf and Kevin