get_include_path — 获取当前的 include_path 配置选项
string get_include_path ( void )
set_include_path — 设置 include_path 配置选项
string set_include_path ( string $new_include_path )
首先set_include_path这个函数呢，是在脚本里动态地对PHP.ini中include_path进行修改的。
而这个include_path呢，它可以针对下面的include和require的路径范围进行限定，或者说是预定义一下。
就好像：
如果我们没有设置这个值，可能我们需要写一些完全的路径：
[php]
include("123/test1.php");
include("123/test2.php");
include("123/test3.php");
require("123/test4.php");
require("123/test5.php");
?>
include("123/test1.php");
include("123/test2.php");
include("123/test3.php");
require("123/test4.php");
require("123/test5.php");
?>
来引入很多外部文件，但是如果我们设置了set_include_path("123/"),我们就可以用下面这段代码代替。
[php]
set_include_path("123/");
include("test1.php");
include("test2.php");
include("test3.php");
require("test4.php");
require("test5.php");
?>
set_include_path("123/");
include("test1.php");
include("test2.php");
include("test3.php");
require("test4.php");
require("test5.php");
?> 那么这个函数它不仅可以定义一个文件夹，我们可以定义很多文件夹。如下所示，我要写一个初始化函数：
[php]
function initialize()
set_include_path(get_include_path().PATH_SEPARATOR . "core/");
set_include_path(get_include_path().PATH_SEPARATOR . "app/");
set_include_path(get_include_path().PATH_SEPARATOR . "admin/");
set_include_path(get_include_path().PATH_SEPARATOR . "lib/");
set_include_path(get_include_path().PATH_SEPARATOR . "include/");
set_include_path(get_include_path().PATH_SEPARATOR."data/");
set_include_path(get_include_path().PATH_SEPARATOR."cache/");
function initialize()
{
set_include_path(get_include_path().PATH_SEPARATOR . "core/");
set_include_path(get_include_path().PATH_SEPARATOR . "app/");
set_include_path(get_include_path().PATH_SEPARATOR . "admin/");
set_include_path(get_include_path().PATH_SEPARATOR . "lib/");
set_include_path(get_include_path().PATH_SEPARATOR . "include/");
set_include_path(get_include_path().PATH_SEPARATOR."data/");
set_include_path(get_include_path().PATH_SEPARATOR."cache/");
} 这样它的路径就成了：
.;C:\php5\pear;core/;app/;admin/;lib/;include/;data/;cache/
下面呢来一个实例.
[php]
$include_path=get_include_path(); //原基目录
$include_path.=PATH_SEPARATOR."include/" ;
$include_path.=PATH_SEPARATOR."classs/";
$include_path.=PATH_SEPARATOR."libs/";
//echo $include_path;
//设置include包含文件所在的所有目录
set_include_path($include_path);
function __autoload($className)
{
//echo '类 '.$className;
include strtolower($className).".class.php";
}
$Smarty = new Smarty;
?>
$include_path=get_include_path(); //原基目录
$include_path.=PATH_SEPARATOR."include/" ;
$include_path.=PATH_SEPARATOR."classs/";
$include_path.=PATH_SEPARATOR."libs/";
//echo $include_path;
//设置include包含文件所在的所有目录
set_include_path($include_path);
function __autoload($className)
{
//echo '类 '.$className;
include strtolower($className).".class.php";
}
$Smarty = new Smarty;
?>
当指定了多个目录为 include_path ，而所要求包含的文件在这几个目录都有相同名称的文件存在时，php选择使用设定 include_path 时排位居前的目录下的文件。
这样就可以 直接new拉!!
