PHP extension and embedding--c extension development helloworld_PHP tutorial

After completing the LAMP configuration environment under Linux, you can proceed with PHP extension development.

Extension development in PHP is under the /ext folder of the source code package. You can see that there are many developed extensions here. For example, database-related mysql and xml processing modules, etc.

First create a folder:

mkdir hello

After entering this folder, first create and open a configuration file:

vim config.m4

This gives an example of a configuration problem:

1 PHP_ARG_ENABLE(sample, whether to enable SAMPLE support,
2 [ --enable-sample Enable SAMPLE support])
3 if test "$PHP_SAMPLE" = "yes"; then
4    AC_DEFINE(SAMPLE, 1, [Whether you have SAMPLE])
5   PHP_NEW_EXTENSION(sample, sample.c, $ext_shared)
6 fi

* This configuration file creates a --enable-hello configuration option, and the second option of PHP_ARG_ENABLE will be displayed during configuration
* The third parameter of PHP_ARG_ENABLE will be displayed when calling ./configurehelp
* Why do I sometimes use enable-xxx and sometimes use with-xxx? enable can be turned off, but with requires additional third-party libraries
* If --enable-hello is present during configuration, then the $PHP_HELLO parameter will be set to yes, and then the next operation can be performed
* PHP_NEW_EXTENSION declares all required source files: PHP_NEW_EXTENSION(sample, sample.c sample2.c sample3.c, $ext_shared)
* The last parameter is usually like this when building a shared module. $ext_shared

The following lists possible configuration options in the config file: * PHP_ARG_WITH or PHP_ARG_ENABLE specifies how the PHP extension module works. The former means no third-party libraries are needed, and the latter is just the opposite;
* PHP_REQUIRE_CXX is used to specify that this extension uses C++;
* PHP_ADD_INCLUDE specifies the header file directory used by PHP extension modules;
* PHP_CHECK_LIBRARY specifies the PHP extension module PHP_ADD_LIBRARY_WITH_PATH definition and library connection error information, etc.;
* PHP_ADD_LIBRARY(stdc++,"",EXTERN_NAME_LIBADD) is used to link the standard C++ library into the extension
* PHP_SUBST(EXTERN_NAME_SHARED_LIBADD) is used to describe how this extension is compiled into a dynamic link library;
* PHP_NEW_EXTENSION is used to specify which source files should be compiled, and the files are separated by spaces;
Next look at the header file: php_sample.h

1  ?#ifndef PHP_SAMPLE_H
2  /* 防止两次引入 */
3  #define PHP_SAMPLE_H
4  /* 定义扩展的性质 */
5  #define PHP_SAMPLE_EXTNAME "sample"
6  #define PHP_SAMPLE_EXTVER "1.0"
7  /* 当在php的源码树之外build的时候，引入配置选项, 在使用phpize工具时，一般都是先定义的 */
8  #ifdef HAVE_CONFIG_H
9  #include "config.h"
10  #endif
11  /* 引入php标准头文件 */
12  #include "php.h"
13  PHP_FUNCTION(hello_world);//声明扩展中的函数
14   /* 定义入口点的符号，zend在加载这个module的时候会用*/
15  extern zend_module_entry sample_module_entry;
16  #define phpext_sample_ptr &sample_module_entry
17  #endif /* PHP_SAMPLE_H */

Finally, note two points: * php.h must be imported
* Declaration zend_module_entry is declared as extern, so when the extension is specified with extension=. . When the form is loaded, Zend can find it through dlopen() and dlsym().


Finally, look at the source file sample.c:

#include "php_sample.h"

    static function_entry php_sample_functions[] = {
    PHP_FE(sample_hello_world, NULL)//任何扩展中的函数都要在这里声明。把函数名输出到了用户空间中
    { NULL, NULL, NULL }
    };
zend_module_entry sample_module_entry = { //创建一个入口
    #if ZEND_MODULE_API_NO >= 20010901 //这个是一个版本号
    STANDARD_MODULE_HEADER,
    #endif
    PHP_SAMPLE_EXTNAME,
    php_sample_functions, /* Functions 这里是把php_function加入到Zend中去*/
    NULL, /* MINIT */
    NULL, /* MSHUTDOWN */
    NULL, /* RINIT */
    NULL, /* RSHUTDOWN */
    NULL, /* MINFO */
    #if ZEND_MODULE_API_NO >= 20010901
    PHP_SAMPLE_EXTVER,
    #endif
    STANDARD_MODULE_PROPERTIES
};
#ifdef COMPILE_DL_SAMPLE
ZEND_GET_MODULE(sample)
#endif //这块区域是当扩展被动态加载的时候，为Zend添加一个引用，记得要添加上就行。
/*真正的函数体的部分*/
PHP_FUNCTION(sample_hello_world)
{
    php_printf("Hello World!\n");
}

This is the content of the source code.
Next, you need to generate the extension: phpize ./configure --enable-sample make sudo make install After executing these statements, you need to add this extension to php.ini: extension=sample.so Then restart apache sudo /etc/init.d/httpd restart
Next, check whether the sample extension is already available on the phpinfo page. If so, verify it in test.php below:

<?php
    sample_hello_world();
?>

If "Hello World!" is printed, it means that the php extension has been developed successfully.

http://www.bkjia.com/PHPjc/621615.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/621615.htmlTechArticleAfter completing the LAMP configuration environment under Linux, you can proceed with PHP extension development. Extension development in php is under the /ext folder of the source code package. You can see that it is already there...