一，搭建php环境
下载php 5.2.6 源码 并解压
编译安装，搭建php环境

二，创建扩展项目
进入源码目录
cd php5.2.6/ext/
./ext_skel --extname=my_ext
创建名字为my_ext的项目，最终会生成my_ext.so

三，更改配置和程序
$ vi ext/my_ext/config.m4

根据你自己的选择将

dnl PHP_ARG_WITH(my_ext, for my_ext support,
dnl Make sure that the comment is aligned:

dnl [  --with-my_ext             Include my_ext support])
修改成

PHP_ARG_WITH(my_ext, for my_ext support,
Make sure that the comment is aligned:

[  --with-my_ext             Include my_ext support])
或者将

dnl PHP_ARG_ENABLE(my_ext, whether to enable my_ext support,
dnl Make sure that the comment is aligned:

dnl [  --enable-my_ext           Enable my_ext support])
修改成

PHP_ARG_ENABLE(my_ext, whether to enable my_ext support,

Make sure that the comment is aligned:
[  --enable-my_ext           Enable my_ext support])

$ vi ext/my_ext/php_my_ext.h

将
PHP_FUNCTION(confirm_my_ext_compiled);       /* For testing, remove later. */
更改为
PHP_FUNCTION(say_hello);    


$ vi ext/my_ext/my_ext.c

将
zend_function_entry php5cpp_functions[] = {
        PHP_FE(confirm_my_ext_compiled,      NULL) /* For testing, remove later. */
        {NULL, NULL, NULL}      /* Must be the last line in php5cpp_functions[] */
};
更改为
zend_function_entry php5cpp_functions[] = {
        PHP_FE(say_hello,       NULL)         
        {NULL, NULL, NULL}      /* Must be the last line in php5cpp_functions[] */
};

在最后添加：
PHP_FUNCTION(say_hello)
{
        zend_printf("hello world\n");
}

四，编译
$ cd my_ext
$ /usr/local/php/bin/phpize
ps: 如果出现：Cannot find autoconf.……的错误信息，则需要安装 autoconf (安装过程略)
$ ./configure  --with-php-config=/usr/local/php/bin/php-config
$ make

这时会编译出 my_ext/modules/my_ext.so

五，配置php.ini
将my_ext.so放入/usr/local/php/ext/目录

$ vi php.ini

修改添加如下：
extension_dir = '/usr/local/php/ext/'
extension=my_ext.so  

六，测试
$ vi test.php
<?php
   say_hello();
?>

$ /usr/local/php/bin/php test.php
hello world.

则大功告成

ps:如有问题请留言，大家共同探讨