How can I change my multilingual urls from this example.com/index.php?lang=en to this example.com/en/?

Somebody told me that example.com/en is more friendly than example.com/index.php?lang=en. How can I change my URL last part from ?lang=en to /en/?

(pd: I don't want to use gettext or any framework like zend to accomplish this)

This is how I'm internationalizing and localizing my web page:

(live example: alexchen.co.nr/)

lang.php:

<?php
function dlang($Var) {
 if(empty($GLOBALS[$Var])) {
  $GLOBALS[$Var]=(!empty($GLOBALS['_SERVER'][$Var]))?
   $GLOBALS['_SERVER'][$Var]:
   (!empty($GLOBALS['HTTP_SERVER_VARS'][$Var]))?
   $GLOBALS['HTTP_SERVER_VARS'][$Var]:'';
 }
}

function language() {
 // Detect HTTP_ACCEPT_LANGUAGE & HTTP_USER_AGENT.
 dlang('HTTP_ACCEPT_LANGUAGE');
 dlang('HTTP_USER_AGENT');

 $_AL=strtolower($GLOBALS['HTTP_ACCEPT_LANGUAGE']);
 $_UA=strtolower($GLOBALS['HTTP_USER_AGENT']);

 // Try to detect Primary language if several languages are accepted.
 foreach($GLOBALS['_LANG'] as $K) {
  if(strpos($_AL, $K)===0)
   return $K;
 }

 // Try to detect any language if not yet detected.
 foreach($GLOBALS['_LANG'] as $K) {
  if(strpos($_AL, $K)!==false)
   return $K;
 }
 foreach($GLOB开发者_如何转开发ALS['_LANG'] as $K) {
  if(preg_match("/[\[\( ]{$K}[;,_\-\)]/",$_UA))
   return $K;
 }

 // Return default language if language is not yet detected.
 return $GLOBALS['_DLANG'];
}

// Define default language.
$GLOBALS['_DLANG']='zh-tw';

// Define all available languages.
// WARNING: uncomment all available languages

$GLOBALS['_LANG'] = array(
 'en',
 'es',
 'zh-tw',
 'zh-cn'
);
?>

session.php:

<?php
//proc all page display
include('lang.php'); //language detector
class Session
{
 var $lang;         //Username given on sign-up
 var $url;          //The page url current being viewed
 var $referrer;     //Last recorded site page viewed

 /* Class constructor */
 function Session() {
  $this->time = time();
  $this->startSession();
 }

 function cf($filename) { //function to clean a filename string so it is a valid filename
  $fp = explode('/',$filename);
  $num = count($fp);
  return $fp[$num-1];
 }

 /**
  * startSession - Performs all the actions necessary to
  * initialize this session object. Tries to determine if the
  * the user has logged in already, and sets the variables
  * accordingly. Also takes advantage of this page load to
  * update the active visitors tables.
  */
 function startSession() {
  session_start();   //Tell PHP to start the session

  /* Set referrer page */
  if(isset($_SESSION['url'])) {
   $this->referrer = $search = $this->cf($_SESSION['url']);
  }
  else {
   $this->referrer = "/";
  }

  /* Set current url */
  $this->url = $_SESSION['url'] = $this->cf($_SERVER['PHP_SELF']);

  /* Set user-determined language: */
  //set up languages array:
  //set cookie
  $langs = array('en','es','zh-tw', 'zh-cn');

  if(isset($_GET['lang'])){
   if(in_array($_GET['lang'],$langs)){
    $this->lang =  $_SESSION['lang'] = $_GET['lang'];
    setcookie("lang", $_SESSION['lang'], time() + (3600 * 24 * 30));
   }
  }
  else if(isSet($_COOKIE['lang'])) {
   $_SESSION['lang'] = $_COOKIE['lang'];
  }
  else {
   $_SESSION['lang'] = 'zh-tw';
  }
 }
};
/**
 * Initialize session object - This must be initialized before g
 * the form object because the form uses session variables,
 * which cannot be accessed unless the session has started.
 */
$session = new Session;
?>

localization.php:

    <?php
    include('session.php'); //language detector

    // determine the value of $lang_file according the one in $lang
    $languages = array('en', 'es', 'zh-tw', 'zh-cn');
    if (in_array($_SESSION['lang'], $languages)) {
        $lang_file = 'lang.'.$_SESSION['lang'].'.php';
    } else {
        $lang_file = 'lang.zh-tw.php';
    }

    // translation helper function
    function l($localization) {
     global $lang;
     return $lang[$localization]; }

    // include file for final output
     include_once 'languages/'.$lang_file;
?>

ModRewrite is your friend. Throw this in your .htaccess file. You may want it to go to your session page instead of index, then redirect with PHP. Note, this only works for one page.

RewriteEngine On
RewriteBase /

# Redirect languages
RewriteRule ^(en|es|zh\-tw|zh\-cn)/?$ index.php?lang=$1 [L]