getting current URL

From the reference:

<?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;
}
?>

You have to be careful relying on server variables, and it depends what the webserver wants to give you... Here's a fairly failsafe way to get the URL.

$url = '';

if (isset($_SERVER['HTTPS']) && filter_var($_SERVER['HTTPS'], FILTER_VALIDATE_BOOLEAN))
    $url .= 'https';
else
    $url .= 'http';

$url .= '://';

if (isset($_SERVER['HTTP_HOST']))
    $url .= $_SERVER['HTTP_HOST'];
elseif (isset($_SERVER['SERVER_NAME']))
    $url .= $_SERVER['SERVER_NAME'];
else
    trigger_error ('Could not get URL from $_SERVER vars');


if ($_SERVER['SERVER_PORT'] != '80')
  $url .= ':'.$_SERVER["SERVER_PORT"];

if (isset($_SERVER['REQUEST_URI']))
    $url .= $_SERVER['REQUEST_URI'];
elseif (isset($_SERVER['PHP_SELF']))
    $url .= $_SERVER['PHP_SELF'];
elseif (isset($_SERVER['REDIRECT_URL']))
    $url .= $_SERVER['REDIRECT_URL'];
else
    trigger_error ('Could not get URL from $_SERVER vars');

echo $url;