C Extension of PHP

One of the core data structures in PHP is this:

typedef　union　_zvalue_value　{
　long　lval;　　　/*　long　value　*/
　double　dval;　　/*　double　value　*/
　struct　{
　char　*val;
　int　len;
　}　str;
　HashTable　*ht;　　/*　hash　table　value　*/
　zend_object_value　obj;
}　zvalue_value;

struct　_zval_struct　{
　/*　Variable　information　*/
　zvalue_value　value;　/*　value　*/
　zend_uint　refcount;
　zend_uchar　type;　/*　active　type　*/
　zend_uchar　is_ref;
};

This data structure is the representation of each data type in PHP in the lower C language. You can see that the first field in the _ZVAL_STRUCT structure is a consortium that stores the actual values, which can be long,double, strings, Hashtable (that is, arrays in PHP), and objects. The 2nd parameter is a reference count, and the third parameter is the current type.

That means that every type in PHP is actually a struct _zval_struct type.

1 first into the PHP source directory under the Ext folder, and then run the following command, this will generate a My_module folder. ：

./ext_skel　--extname=my_module

2 then declare your PHP function name in my_module.h:

PHP_FUNCTION(my_function);

2 in the my_module.c file My_module_functions (the module is the name of the extension module you created) Add the PHP method name you want to write:

PHP_FE(my_function,　NULL)

3 The next step is to implement Php_function (My_function).

First, the parsing of the arguments, when passing in the type of PHP and the conversion between the type of C:

The functions to be used here are:

int　zend_parse_parameters(int　num_args　TSRMLS_DC,　char　*type_spec,　...);

The PHP type and type C correspond to the following:

Reference

L-long

D-double

S-string (with possible null bytes) and its length

B-boolean

R-resource, stored in zval*

A-array, stored in zval*

O-object (of any class), stored in zval*

O-object (of class specified by class entry), stored in zval*

z-the actual zval*