Developing Custom PHP Extensions: Part 1 - Our First Extension
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If you followed all of the instructions carefully then you should be able to commence writing your own extensions. I will leave all the serious coding to the next article and just show you a basic extension that prints "Hello World" five times. Copy and paste the following code into your project; compile and build it:
/* include standard header */
/* you will need to include this in all of your php extension projects*/
#include "php.h"
/* All the functions that will be exported (available) must be declared */
ZEND_FUNCTION(hello_world);
PHP_MINFO_FUNCTION(devarticlesmod);
/* Just a basic int to be used as a counter*/
int i;
/* function list so that the Zend engine will know what’s here */
zend_function_entry devarticlesmod_functions[] =
{
ZEND_FE(hello_world, NULL)
{NULL, NULL, NULL}
};
/* module information */
zend_module_entry devarticlesmod_module_entry =
{ STANDARD_MODULE_HEADER,
"DevArticles",
devarticlesmod_functions,
NULL,
NULL,
NULL,
NULL,
PHP_MINFO(devarticlesmod),
NO_VERSION_YET,
STANDARD_MODULE_PROPERTIES };
#if COMPILE_DL_DEVARTICLES_MOD
ZEND_GET_MODULE(devarticlesmod)
#endif
PHP_MINFO_FUNCTION(devarticlesmod)
{
php_info_print_table_start();
php_info_print_table_row(2, "DevArticles Extension", "All Systems Go");
php_info_print_table_end();
}
ZEND_FUNCTION(hello_world)
{
for(i=0;i<5;i++)
{
zend_printf("Hello World<br>");
}
} Don't worry if you do not understand a lot of what's in the C code above. This article is only meant to show you how to setup the environment and explain how to use the extensions in your scripts. All of the code-related material will be explained in the subsequent article(s).
After you've compiled and built the extension, you should take the newly created .dll file (php_devarticlesmod.dll in our case) and place it in your web-server directory. In that same directory, create a new PHP file and type the following:
<?php
dl("php_devarticlesmod.dll");
hello_world();
phpinfo();
?> The first line tells php to load the module/extension. The function takes the name of the extension file as the parameter.
The second line, hello_world(), is the function we created in our extension. Upon calling this function you should see "Hello World" printed five times on the screen.
And, lastly, phpinfo() is called. If you scroll down through the output you should see a confirmation that your extension is indeed loaded:
Next: Conclusion >>
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