Use:

$base_dir = __DIR__; // Absolute path to your installation, ex: /var/www/mywebsite
$doc_root = preg_replace("!{$_SERVER['SCRIPT_NAME']}$!", '', $_SERVER['SCRIPT_FILENAME']); # ex: /var/www
$base_url = preg_replace("!^{$doc_root}!", '', $base_dir); # ex: '' or '/mywebsite'
$base_url = str_replace('\\', '/', $base_url);//On Windows
$base_url = str_replace($doc_root, '', $base_url);//On Windows
$protocol = empty($_SERVER['HTTPS']) ? 'http' : 'https';
$port = $_SERVER['SERVER_PORT'];
$disp_port = ($protocol == 'http' && $port == 80 || $protocol == 'https' && $port == 443) ? '' : ":$port";
$domain = $_SERVER['SERVER_NAME'];
$full_url = "$protocol://{$domain}{$disp_port}{$base_url}"; # Ex: 'http://example.com', 'https://example.com/mywebsite', etc. 

来源:PHP文档根，路径和URL检测

$page_url = (isset($_SERVER['HTTPS']) ? "https" : "http") . "://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";

更多信息:如何使用PHP获取页面的完整URL

清晰的代码，工作在所有的web服务器(Apache, nginx, IIS，…)

$url = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' ? 'https' : 'http') . '://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];

function full_path()
{
    $s = &$_SERVER;
    $ssl = (!empty($s['HTTPS']) && $s['HTTPS'] == 'on') ? true:false;
    $sp = strtolower($s['SERVER_PROTOCOL']);
    $protocol = substr($sp, 0, strpos($sp, '/')) . (($ssl) ? 's' : '');
    $port = $s['SERVER_PORT'];
    $port = ((!$ssl && $port=='80') || ($ssl && $port=='443')) ? '' : ':'.$port;
    $host = isset($s['HTTP_X_FORWARDED_HOST']) ? $s['HTTP_X_FORWARDED_HOST'] : (isset($s['HTTP_HOST']) ? $s['HTTP_HOST'] : null);
    $host = isset($host) ? $host : $s['SERVER_NAME'] . $port;
    $uri = $protocol . '://' . $host . $s['REQUEST_URI'];
    $segments = explode('?', $uri, 2);
    $url = $segments[0];
    return $url;
}

注意:我刚刚更新了Timo Huovinen的代码，所以你不会在URL中得到任何get参数。这个URL很简单，删除了诸如?hi=i&am=a&get之类的东西。

例子:

http://www.example.com/index?get=information

将显示为:

http://www.example.com/index

这很好，除非您使用GET参数来定义一些特定的内容，在这种情况下，您应该使用他的代码!: -)

我用这个函数来处理URL:

 <?php
     function curPageURL()
     {
         $pageURL = 'http';
         if ($_SERVER["HTTPS"] == "on") {$pageURL .= "s";}
         $pageURL .= "://";
         if ($_SERVER["SERVER_PORT"] != "80") {
             $pageURL .=
             $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
         }
         else {
             $pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
         }
         return $pageURL;
     }
 ?>

与接受的答案相同的技术，但支持HTTPS，并且更易于阅读:

$current_url = sprintf(
    '%s://%s/%s',
    isset($_SERVER['HTTPS']) ? 'https' : 'http',
    $_SERVER['HTTP_HOST'],
    $_SERVER['REQUEST_URI']
);

上面给出了不必要的斜杠。在我的设置中，Request_URI有开头和结尾的斜杠。这个比较适合我。

$Current_Url = sprintf(
   '%s://%s/%s',
   isset($_SERVER['HTTPS']) ? 'https' : 'http',
   $_SERVER['HTTP_HOST'],
   trim($_SERVER['REQUEST_URI'],'/\\')
);