11111

Declaration of the Zend Function Block Пред.

Глава 51. Source Discussion

След.

Declaration of the Zend Function Block

- Now that you have declared the functions to be exported, you also

have to introduce them to Zend. Introducing the list of functions is done by

using an array of zend_function_entry. This array consecutively

contains all functions that are to be made available externally, with the function's name

as it should appear in PHP and its name as defined in the C source.

Internally, zend_function_entry is defined as shown in

Прим. 51-1.

-

Пример 51-1. Internal declaration of zend_function_entry.
typedef struct _zend_function_entry {

char *fname;

void (*handler)(INTERNAL_FUNCTION_PARAMETERS);

unsigned char *func_arg_types;

} zend_function_entry;

EntryDescription
fname- Denotes the function name as seen in PHP (for

example, fopen, mysql_connect, or, in our

example, first_module).

handler- Pointer to the C function responsible for handling calls

to this function. For example, see the standard macro

INTERNAL_FUNCTION_PARAMETERS discussed earlier.

func_arg_types- Allows you to mark certain parameters so that they're forced

to be passed by reference. You usually should set this to

NULL.

In the example above, the declaration looks like this: 

zend_function_entry firstmod_functions[] =

{

ZEND_FE(first_module, NULL)

{NULL, NULL, NULL}

};

You can see that the last entry in the list always has to be

{NULL, NULL, NULL}.

This marker has to be set for Zend to know when the end of the

list of exported functions is reached.

Замечание:

You cannot use the predefined macros for the

end marker, as these would try to refer to a function named "NULL"!

- The macro ZEND_FE (short for 'Zend Function

Entry') simply expands to a structure entry in

zend_function_entry. Note that these macros

introduce a special naming scheme to your functions - your C

functions will be prefixed with zif_, meaning

that ZEND_FE(first_module) will refer to a C

function zif_first_module(). If you want to mix

macro usage with hand-coded entries (not a good practice), keep

this in mind.

- Tip: Compilation errors that refer to functions

named zif_*() relate to functions defined

with ZEND_FE.

- Табл. 51-2 shows a list of all the macros

that you can use to define functions.

Таблица 51-2. Macros for Defining Functions
Macro NameDescription
ZEND_FE(name, arg_types)- Defines a function entry of the name name in

zend_function_entry. Requires a corresponding C

function. arg_types needs to be set to NULL.

This function uses automatic C function name generation by prefixing the PHP

function name with zif_.

For example, ZEND_FE("first_module", NULL) introduces a

function first_module() to PHP and links it to the C

function zif_first_module(). Use in conjunction

with ZEND_FUNCTION.

- ZEND_NAMED_FE(php_name, name, arg_types)

- Defines a function that will be available to PHP by the

name php_name and links it to the corresponding C

function name. arg_types needs to be set

to NULL. Use this function if you don't want the automatic

name prefixing introduced by ZEND_FE. Use in conjunction

with ZEND_NAMED_FUNCTION.

- ZEND_FALIAS(name, alias, arg_types)

- Defines an alias named alias for

name. arg_types needs to be set

to NULL. Doesn't require a corresponding C

function; refers to the alias target instead.

PHP_FE(name, arg_types)- Old PHP API equivalent of ZEND_FE.

- PHP_NAMED_FE(runtime_name, name, arg_types)

- Old PHP API equivalent of ZEND_NAMED_FE.

- Note: You can't use

ZEND_FE in conjunction with

PHP_FUNCTION, or PHP_FE in

conjunction with ZEND_FUNCTION. However, it's

perfectly legal to mix ZEND_FE and

ZEND_FUNCTION with PHP_FE

and PHP_FUNCTION when staying with the same

macro set for each function to be declared. But mixing is

not recommended; instead, you're advised to

use the ZEND_* macros only.

Пред.

Начало

След.

Declaring Exported Functions

Уровень выше

Declaration of the Zend Module Block 22222

Free Web Hosting