预定义变量

自 PHP 4.1.0 起,取得外部变量的首选方法是用下面提及的超全局变量。在此之前,人们要么依赖 register_globals,要么就是长长的预定义 PHP 数组($HTTP_*_VARS)。自 PHP 5.0.0 起,长格式的 PHP 预定义变量可以通过设置 register_long_arrays 来屏蔽。

服务器变量:$_SERVER

注意: 在 PHP 4.1.0 及以后版本使用。之前的版本,使用 $HTTP_SERVER_VARS

$_SERVER 是一个包含诸如头信息(header)、路径(path)和脚本位置(script locations)的数组。数组的实体由 web 服务器创建。不能保证所有的服务器都能产生所有的信息;服务器可能忽略了一些信息,或者产生了一些未在下面列出的新的信息。这意味着,大量的这些变量在 CGI 1.1 规范中说明,所以应该仔细研究一下。

这是一个“superglobal”,或者可以描述为自动全局变量。这只不过意味这它在所有的脚本中都有效。在函数或方法中不需要使用 global $_SERVER; 访问它,就如同使用 $HTTP_SERVER_VARS 一样。

$HTTP_SERVER_VARS 包含着同样的信息,但是不是一个自动全局变量(注意:$HTTP_SERVER_VARS$_SERVER 是不同的变量,PHP 处理它们的方式不同)。

如果设置了 register_globals 指令,这些变量也在所有脚本中可用;也就是,分离了 $_SERVER$HTTP_SERVER_VARS 数组。相关信息,请参阅安全的相关章节使用 Register Globals。这些单独的全局变量不是自动全局变量。

或许会发现下面列出的某些 $_SERVER 元素并不可用。注意,如果以命令行方式运行 PHP,下面列出的元素几乎没有有效的(或是没有任何实际意义的)。

PHP_SELF

当前正在执行脚本的文件名,与 document root 相关。举例来说,在 URL 地址为 http://example.com/test.php/foo.bar 的脚本中使用 $_SERVER['PHP_SELF'] 将会得到 /test.php/foo.bar 这个结果。__FILE__ 常量包含当前(例如包含)文件的绝对路径和文件名。

如果 PHP 以命令行方式运行,该变量在 PHP 4.3.0 之前无效。

argv

传递给该脚本的参数。当脚本运行在命令行方式时,argv 变量传递给程序 C 语言样式的命令行参数。当调用 GET 方法时,该变量包含请求的数据。

argc

包含传递给程序的命令行参数的个数(如果运行在命令行模式)。

GATEWAY_INTERFACE

服务器使用的 CGI 规范的版本。例如,“CGI/1.1”。

SERVER_ADDR

当前运行脚本所在的服务器的 IP 地址。

SERVER_NAME

当前运行脚本所在服务器主机的名称。如果该脚本运行在一个虚拟主机上,该名称是由那个虚拟主机所设置的值决定。

SERVER_SOFTWARE

服务器标识的字串,在响应请求时的头信息中给出。

SERVER_PROTOCOL

请求页面时通信协议的名称和版本。例如,“HTTP/1.0”。

REQUEST_METHOD

访问页面时的请求方法。例如:“GET”、“HEAD”,“POST”,“PUT”。

注意: 如果请求的方式是 HEAD,PHP 脚本将在送出头信息后中止(这意味着在产生任何输出后,不再有输出缓冲)。

REQUEST_TIME

请求开始时的时间戳。从 PHP 5.1.0 起有效。

QUERY_STRING

查询(query)的字符串(URL 中第一个问号 ? 之后的内容)。

DOCUMENT_ROOT

当前运行脚本所在的文档根目录。在服务器配置文件中定义。

HTTP_ACCEPT

当前请求的 Accept: 头信息的内容。

HTTP_ACCEPT_CHARSET

当前请求的 Accept-Charset: 头信息的内容。例如:“iso-8859-1,*,utf-8”。

HTTP_ACCEPT_ENCODING

当前请求的 Accept-Encoding: 头信息的内容。例如:“gzip”。

HTTP_ACCEPT_LANGUAGE

当前请求的 Accept-Language: 头信息的内容。例如:“en”。

HTTP_CONNECTION

当前请求的 Connection: 头信息的内容。例如:“Keep-Alive”。

HTTP_HOST

当前请求的 Host: 头信息的内容。

HTTP_REFERER

链接到当前页面的前一页面的 URL 地址。不是所有的用户代理(浏览器)都会设置这个变量,而且有的还可以手工修改 HTTP_REFERER。因此,这个变量不总是真实正确的。

HTTP_USER_AGENT

当前请求的 User-Agent: 头信息的内容。该字符串表明了访问该页面的用户代理的信息。一个典型的例子是:Mozilla/4.5 [en] (X11; U; Linux 2.2.9 i586)。也可以使用 get_browser() 得到此信息。

HTTPS

如果脚本是通过 HTTPS 协议被访问,则被设为一个非空的值。

REMOTE_ADDR

正在浏览当前页面用户的 IP 地址。

REMOTE_HOST

正在浏览当前页面用户的主机名。反向域名解析基于该用户的 REMOTE_ADDR

注意: 必须配置 Web 服务器来建立此变量。例如 Apache 需要在 httpd.conf 中有 HostnameLookups On。参见 gethostbyaddr()

REMOTE_PORT

用户连接到服务器时所使用的端口。

SCRIPT_FILENAME

当前执行脚本的绝对路径名。

注意: 如果脚本在 CLI 中被执行,作为相对路径,例如 file.php../file.php$_SERVER['SCRIPT_FILENAME'] 将包含用户指定的相对路径。

SERVER_ADMIN

该值指明了 Apache 服务器配置文件中的 SERVER_ADMIN 参数。如果脚本运行在一个虚拟主机上,则该值是那个虚拟主机的值。

SERVER_PORT

服务器所使用的端口。默认为“80”。如果使用 SSL 安全连接,则这个值为用户设置的 HTTP 端口。

SERVER_SIGNATURE

包含服务器版本和虚拟主机名的字符串。

PATH_TRANSLATED

当前脚本所在文件系统(不是文档根目录)的基本路径。这是在服务器进行虚拟到真实路径的映像后的结果。

注意: PHP 4.3.2 之后,PATH_TRANSLATED 在 Apache 2 SAPI 模式下不再和 Apache 1 一样隐含赋值,而是若 Apache 不生成此值,PHP 便自己生成并将其值放入 SCRIPT_FILENAME 服务器常量中。这个修改遵守了 CGI 规范,PATH_TRANSLATED 仅在 PATH_INFO 被定义的条件下才存在。

Apache 2 用户可以使用 httpd.conf 中的 AcceptPathInfo On 来定义 PATH_INFO

SCRIPT_NAME

包含当前脚本的路径。这在页面需要指向自己时非常有用。__FILE__ 包含当前文件的绝对路径和文件名(例如包含文件)。

REQUEST_URI

访问此页面所需的 URI。例如,“/index.html”。

PHP_AUTH_DIGEST

当作为 Apache 模块运行时,进行 HTTP Digest 认证的过程中,此变量被设置成客户端发送的“Authorization”HTTP 头内容(以便作进一步的认证操作)。

PHP_AUTH_USER

当 PHP 运行在 Apache 或 IIS(PHP 5 是 ISAPI)模块方式下,并且正在使用 HTTP 认证功能,这个变量便是用户输入的用户名。

PHP_AUTH_PW

当 PHP 运行在 Apache 或 IIS(PHP 5 是 ISAPI)模块方式下,并且正在使用 HTTP 认证功能,这个变量便是用户输入的密码。

AUTH_TYPE

当 PHP 运行在 Apache 模块方式下,并且正在使用 HTTP 认证功能,这个变量便是认证的类型。

环境变量:$_ENV

注意: 在 PHP 4.1.0 及以后版本使用。之前的版本,使用 $HTTP_ENV_VARS

在解析器运行时,这些变量从环境变量转变为 PHP 全局变量名称空间(namespace)。它们中的许多都是由 PHP 所运行的系统决定。完整的列表是不可能的。请查看系统的文档以确定其特定的环境变量。

其它环境变量(包括 CGI 变量),无论 PHP 是以服务器模块或是以 CGI 处理方式运行,都在这里列出了。

这是一个“superglobal”,或者可以描述为自动全局变量。这只不过意味这它在所有的脚本中都有效。在函数或方法中不需要使用 global $_ENV; 来访问它,就如同使用 $HTTP_ENV_VARS 一样。

$HTTP_ENV_VARS 包含着同样的信息,但是不是一个自动全局变量(注意:$HTTP_ENV_VARS$_ENV 是不同的变量,PHP 处理它们的方式不同)。

如果设置了 register_globals 指令,这些变量也在所有脚本中可用;也就是,分离了 $_ENV$HTTP_ENV_VARS 数组。相关信息,请参阅安全的相关章节使用 Register Globals。这些单独的全局变量不是自动全局变量。

HTTP Cookies:$_COOKIE

注意: 在 PHP 4.1.0 及以后版本使用。之前的版本,使用 $HTTP_COOKIE_VARS

通过 HTTP cookies 传递的变量组成的数组。是自动全局变量。

这是一个“superglobal”,或者可以描述为自动全局变量。这只不过意味这它在所有的脚本中都有效。在函数或方法中不需要使用 global $_COOKIE; 来访问它,就如同使用 $HTTP_COOKIE_VARS 一样。

$HTTP_COOKIE_VARS 包含着同样的信息,但是不是一个自动全局变量(注意:$HTTP_COOKIE_VARS$_COOKIE 是不同的变量,PHP 处理它们的方式不同)。

如果设置了 register_globals 指令,这些变量也在所有脚本中可用;也就是,分离了 $_COOKIE$HTTP_COOKIE_VARS 数组。相关信息,请参阅安全的相关章节使用 Register Globals。这些单独的全局变量不是自动全局变量。

HTTP GET 变量:$_GET

注意: 在 PHP 4.1.0 及以后版本使用。之前的版本,使用 $HTTP_GET_VARS

通过 HTTP GET 方法传递的变量组成的数组。是自动全局变量。

这是一个“superglobal”,或者可以描述为自动全局变量。这只不过意味这它在所有的脚本中都有效。在函数或方法中不需要使用 global $_GET; 来访问它,就如同使用 $HTTP_GET_VARS 一样。

$HTTP_GET_VARS 包含着同样的信息,但是不是一个自动全局变量(注意:$HTTP_GET_VARS$_GET 是不同的变量,PHP 处理它们的方式不同)。

如果设置了 register_globals 指令,这些变量也在所有脚本中可用;也就是,分离了 $_GET$HTTP_GET_VARS 数组。相关信息,请参阅安全的相关章节使用 Register Globals。这些单独的全局变量不是自动全局变量。

HTTP POST 变量:$_POST

注意: 在 PHP 4.1.0 及以后版本使用。之前的版本,使用 $HTTP_POST_VARS

通过 HTTP POST 方法传递的变量组成的数组。是自动全局变量。

这是一个“superglobal”,或者可以描述为自动全局变量。这只不过意味这它在所有的脚本中都有效。在函数或方法中不需要使用 global $_POST; 来访问它,就如同使用 $HTTP_POST_VARS 一样。

$HTTP_POST_VARS 包含着同样的信息,但是不是一个自动全局变量(注意:$HTTP_POST_VARS$_POST 是不同的变量,PHP 处理它们的方式不同)。

如果设置了 register_globals 指令,这些变量也在所有脚本中可用;也就是,分离了 $_POST$HTTP_POST_VARS 数组。相关信息,请参阅安全的相关章节使用 Register Globals。这些单独的全局变量不是自动全局变量。

HTTP 文件上传变量:$_FILES

注意: 在 PHP 4.1.0 及以后版本使用。之前的版本,使用 $HTTP_POST_FILES

通过 HTTP POST 方法传递的已上传文件项目组成的数组。是自动全局变量。

这是一个“superglobal”,或者可以描述为自动全局变量。这只不过意味这它在所有的脚本中都有效。在函数或方法中不需要使用 global $_FILES; 来访问它,就如同使用 $HTTP_POST_FILES 一样。

$HTTP_POST_FILES 包含着同样的信息,但是不是一个自动全局变量(请注意 PHP 是把 $HTTP_POST_FILES$_FILES 这两个变量当作不同的变量来处理的)。

如果设置了 register_globals 指令,这些变量也在所有脚本中可用;也就是,分离了 $_FILES$HTTP_POST_FILES 数组。相关信息,请参阅安全的相关章节使用 Register Globals。这些单独的全局变量不是自动全局变量。

Request 变量:$_REQUEST

注意: 在 PHP 4.1.0 及以后版本使用。之前的版本,没有等价的数组。

注意: 在 PHP 4.3.0 之前,$_FILES 也被包括在 $_REQUEST 数组中。

此关联数组包含 $_GET$_POST$_COOKIE 中的全部内容。

这是一个“superglobal”,或者可以描述为自动全局变量。这只不过意味着它在所有的脚本中都有效。在函数或方法中不需要使用 global $_REQUEST; 来访问它。

如果设置了 register_globals 指令,这些变量也在所有脚本中可用;也就是,分离了 $_REQUEST 数组。相关信息,请参阅安全的相关章节使用 Register Globals。这些单独的全局变量不是自动全局变量。

Session 变量:$_SESSION

注意: 在 PHP 4.1.0 及以后版本使用。之前的版本,使用 $HTTP_SESSION_VARS

包含当前脚本中 session 变量的数组。参阅 Session 函数文档以获得更多信息。

这是一个“superglobal”,或者可以描述为自动全局变量。这只不过意味这它在所有的脚本中都有效。在函数或方法中不需要使用 global $_SESSION; 来访问它,就如同使用 $HTTP_SESSION_VARS 一样。

$HTTP_SESSION_VARS 包含着同样的信息,但是不是一个自动全局变量(请注意 PHP 是把 $HTTP_SESSION_VARS$_SESSION 这两个变量当作不同的变量来处理的)。

如果设置了 register_globals 指令,这些变量也在所有脚本中可用;也就是,分离了 $_SESSION$HTTP_SESSION_VARS 数组。相关信息,请参阅安全的相关章节使用 Register Globals。这些单独的全局变量不是自动全局变量。

Global 变量:$GLOBALS

注意: $GLOBALS 在 PHP 3.0.0 及以后版本中适用。

由所有已定义全局变量组成的数组。变量名就是该数组的索引。

这是一个“superglobal”,或者可以描述为自动全局变量。这只不过意味这它在所有的脚本中都有效。在函数或方法中不需要使用 global $GLOBALS; 来访问它。

前一个错误消息:$php_errormsg

$php_errormsg 是包含 PHP 产生的上一错误消息内容的变量。该变量在发生错误并且 track_errors 选项打开(默认为关闭)后才有效。


add a note add a note User Contributed Notes
anonymous
10-Aug-2007 03:48
To get the filename use:

basename($_SERVER['SCRIPT_FILENAME'])
andres at andresj dot ath dot cx
05-Aug-2007 04:41
To get the directory of the current script: (I think this is a little more resource-friendly, but then again with all the fast computers available, it does not matter so much...)
<?
// For the script that is running:
$script_directory = substr($_SERVER['SCRIPT_FILENAME'], 0, strrpos($_SERVER['SCRIPT_FILENAME'], '/'));
// If your script is included from another script:
$included_directory = substr(__FILE__, 0, strrpos(__FILE__, '/'));
echo
$script_directory . '<br />';
echo
$included_directory . '<br />';
?>
If you have a script that only includes the script written above in a directory called 'includer', and I access it from a web browser, this will be what I see:

/path/to/includer/
/path/to/included/
From Under A Rock...
31-Jul-2007 08:49
This small snippet will build the current script's url.  No muss, no fuss:

<?php

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

?>
opez.org
30-Jul-2007 03:14
I couldn't find a better way... Here is a simple line of code that will give you the path to the current file/script:

<?php

$path_only
= implode("/", (explode('/', $_SERVER["SCRIPT_FILENAME"], -1)));

print
$path_only; // /home/worldpeace/public_html/test

print $_SERVER["SCRIPT_FILENAME"]; // /home/worldpeace/public_html/test/test.php

?>

I use this to build INCLUDE commands that call a file determined by a variable [ path + / + file ]. Dont forget the /

I hope this inspires someone.
mathiasrav at gmail dot com
28-Jul-2007 08:31
Based on dlyaza's snippet posted at 22-Oct-2006 12:33, here's getip() which gets the IP, first checking some known custom proxy headers for validity and then falling back to REMOTE_ADDR if none are found/match.

<?php
function getip() {
  static
$ip = false;
  if (
$ip !== false) return $ip;
  foreach (array(
'HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED', 'HTTP_FORWARDED_FOR', 'HTTP_FORWARDED', 'REMOTE_ADDR') as $aah) {
   if (!isset(
$_SERVER[$aah])) continue;
  
$curip = $_SERVER[$aah];
  
$curip = explode('.', $curip);
   if (
count($curip) !== 4) break; // If they've sent at least one invalid IP, break out
  
foreach ($curip as &$sup) if (($sup = intval($sup)) < 0 or $sup > 255) break 2;
  
$curip_bin = $curip[0] << 24 | $curip[1] << 16 | $curip[2] << 8 | $curip[3];
   foreach (array(
    
//    hexadecimal ip  ip mask
    
array(0x7F000001,    0xFFFF0000), // 127.0.*.*
    
array(0x0A000000,    0xFFFF0000), // 10.0.*.*
    
array(0xC0A80000,    0xFFFF0000), // 192.168.*.*
  
) as $ipmask) {
     if ((
$curip_bin & $ipmask[1]) === ($ipmask[0] & $ipmask[1])) break 2;
   }
   return
$ip = $curip;
  }
  return
$ip = $_SERVER['REMOTE_ADDR'];
}
?>
jmv a jmvware d com
25-Jul-2007 07:32
The preceding note by krausbn works well, but be aware that whatever you use to parse it needs to urldecode the data
krausbn at php dot net
12-Jul-2007 11:35
On very low level POSTs (AJAX, XML RPC etc.) the $GLOBALS['HTTP_RAW_POST_DATA'] var might not contain data because of your php.ini settings. If that's the case you can use php://input to retrieve this low level data:

   // read raw POST data
$input = file_get_contents('php://input');
seb at omegasoft dot co dot uk
11-Jul-2007 02:19
More attractive way for displaying a URL

<?php

function get_url($show_port = false)
{
   if(
$_SERVER['HTTPS'])
   {
      
$my_url = 'https://';
   }
   else
   {
      
$my_url = 'http://';
   }

  
$my_url .= $_SERVER['HTTP_HOST'];

   if(
$show_port)
   {
      
$my_url .= ':' . $_SERVER['SERVER_PORT'];
   }

  
$my_url .= $_SERVER['SCRIPT_NAME'];

   if(
$_SERVER['QUERY_STRING'] != null)
   {   
      
$my_url .= '?' . $_SERVER['QUERY_STRING'];
   }

   return
$my_url;
}

echo
get_url(); // Outputs: http://localhost/
echo get_url(true); // Outputs: http://localhost:80/

?>
djaped at yahoo dot com
20-Jun-2007 02:49
Current Page URL
<?php
$urlh
= getenv(HTTP_HOST);
$url = "http://$urlh";
echo
' '.$url.$_SERVER['SCRIPT_NAME'];
?>
pecili
mike
12-Jun-2007 08:19
<?php
  
/*
   Simple function to get current page URL using comman PHP variables
  
   Function inputs:
       $base if set to true will add the basename to the URL
       $www if set to true will add www. to host if not found
       $query if set to true will add the query string to the URL
       $echo if set to true will echo the URL instead of just returning it
   */
  
function get_url($base = true, $www = true, $query = true, $echo = false){
      
$URL = ''; //open return variable
      
$URL .= (($_SERVER['HTTPS'] != '') ? "https://" : "http://"); //get protocol
      
$URL .= (($www == true && !preg_match("/^www\./", $_SERVER['HTTP_HOST'])) ? 'www.'.$_SERVER['HTTP_HOST'] : $_SERVER['HTTP_HOST']); //get host
      
$path = (($_SERVER['REQUEST_URI'] != '') ? $_SERVER['REQUEST_URI'] : $_SERVER['PHP_SELF']); //tell the function what path variable to use
      
$URL .= ((pathinfo($path, PATHINFO_DIRNAME) != '/') ? pathinfo($path, PATHINFO_DIRNAME).'/' : pathinfo($path, PATHINFO_DIRNAME)); //set up directory
      
$URL .= (($base == true) ? pathinfo($path, PATHINFO_BASENAME) : ""); //add basename
      
$URL  = preg_replace("/\?".preg_quote($_SERVER['QUERY_STRING'])."/", "", $URL); //remove query string if found in url
      
$URL .= (($query == true && $_SERVER['QUERY_STRING'] != '') ? "?".$_SERVER['QUERY_STRING'] : ""); //add query string
      
if($echo == true){
           echo
$URL;
       }else{
           return
$URL;
       }
   }
  
  
/* Example */
  
$page_url = get_url();
   echo
$page_url;
?>
Mike
22-May-2007 09:27
Using HTTP_REFERER and parse_url() to display the host of the URL that a vistor came to your site from.

<?php
  
if($_SERVER['HTTP_REFERER'] != ''){
      
$URL = parse_url($_SERVER['HTTP_REFERER']);
       echo
"Welcome, <b>".$URL['host']."</b> visitor!";
   }
?>
deceze at gmail dot YesThatsGoogleMail dot com
11-Apr-2007 02:37
If you're working with $_GET a lot and need to preserve already set variables in a link for the next page, this function is pretty handy for simplifying the process of generating a new URL:

string setUrlVariables([string var, string value], [varN, valueN], ...)

<?php

function setUrlVariables() {
 
$arg = array();
 
$string = "?";
 
$vars = $_GET;
  for (
$i = 0; $i < func_num_args(); $i++)
  
$arg[func_get_arg($i)] = func_get_arg(++$i);
  foreach (
array_keys($arg) as $key)
  
$vars[$key] = $arg[$key];
  foreach (
array_keys($vars) as $key)
   if (
$vars[$key] != "") $string.= $key . "=" . $vars[$key] . "&";
  if (
SID != "" && SID != "SID" && $_GET["PHPSESSID"] == "")
  
$string.= htmlspecialchars(SID) . "&";

  return
htmlspecialchars(substr($string, 0, -1));
}

?>

You use it like this:

<a href="nextpage.php<?php echo setUrlVariables(); ?>">Link</a>

In this case setUrlVariables() will simply add all the $_GET variables of the current page/URL and even takes care of the PHPSESSID if you use one (and didn't change the default variable name). The above HREF would complete to e.g.:

"nextpage.php?var=21&amp;PHPSESSID=BI89J"

If you supply arguments, do it like this:

<?php echo setUrlVariables("user", "foobar"); ?>

This would complete the HREF to e.g.:

"nextpage.php?user=foobar&amp;var=21&amp;PHPSESSID=BI89J"

Unsetting variables works by supplying an empty value:

<?php echo setUrlVariables("var", ""); ?>

"nextpage.php?user=foobar&amp;PHPSESSID=BI89J"

setUrlVariables() also makes sure it produces "pretty URLs", so it doesn't output any unnecessary garbage. ;)

<?php
  session_destroy
();
  echo
setUrlVariables("user", "");
?>

"nextpage.php"
danvasile at pentest dot ro
21-Mar-2007 08:22
If you have problems with $_SERVER['HTTPS'], especially if it returns no values at all you should check the results of phpinfo(). It might not be listed at all.
Here is a solution to check and change, if necessary, to ssl/https that will work in all cases:

<?php
if ($_SERVER['SERVER_PORT']!=443) {
$sslport=443; //whatever your ssl port is
$url = "https://". $_SERVER['SERVER_NAME'] . ":" . $sslport . $_SERVER['REQUEST_URI'];
header("Location: $url");
}
?>

Of course, this should be done before any html tag or php echo/print.
bosmeew at gmail dot com
18-Feb-2007 02:43
To get the server address, you can use $_SERVER['SERVER_ADDR']. However, this only works when your PHP process is running on a webserver, not when running PHP as CLI. Here is a function which will also return the server address when running on linux (eth0 is hardcoded as the network interface, modify if necessary).

<?php

function getServerAddress() {
   if(
$_SERVER['SERVER_ADDR']) {
       return
$_SERVER['SERVER_ADDR'];
   }
  
  
$ifconfig = shell_exec('/sbin/ifconfig eth0');
  
preg_match('/addr:([\d\.]+)/',$ifconfig,$match);
  
   return
$match[1];
}

?>
borg at sven-of-nine dot de
30-Jan-2007 11:22
Simple function to determine if a visitor is an agent or not

function isbot($agent="")
   {
   //Handfull of Robots
   $bot_array      =array("jeevesteoma",
                                   "msnbot",
                                   "slurp",
                                   "jeevestemoa",
                                   "gulper",
                                   "googlebot",
                                   "linkwalker",
                                   "validator",
                                   "webaltbot",
                                   "wget");
   //no agent given => read from globals
   if ($agent=="")
       {
       @$agent=$_SERVER["HTTP_USER_AGENT"];
       }
   //replace all but alpha
   $agent=strtolower(preg_replace("/[^a-zA-Z _]*/","",$agent));
   //check fr intersections
   return((BOOL)count(array_intersect(explode(" ",$agent),$bot_array)));
   }
Joe Marty
24-Jan-2007 07:53
I think it is very important to note that PHP will automatically replace dots ('.') AND spaces (' ') with underscores ('_') in any incoming POST or GET (or REQUEST) variables.

This page notes the dot replacement, but not the space replacement:
http://us2.php.net/manual/en/language.variables.external.php

The reason is that '.' and ' ' are not valid characters to use in a variable name.  This is confusing to many people, because most people use the format $_POST['name'] to access these values.  In this case, the name is not used as a variable name but as an array index, in which those characters are valid.

However, if the register_globals directive is set, these names must be used as variable names.  As of now, PHP converts the names for these variables before inserting them into the external variable arrays, unfortunately - rather than leaving them as they are for the arrays and changing the names only for the variables set by register_globals.

If you want to use:
<input name="title for page3.php" type="text">

The value you will get in your POST array, for isntance would be:
$_POST['title_for_page3_php']
NeoSmart Technologies
18-Nov-2006 02:22
The *only* way to make Request_URI work as a 100% Apache-Compliant server variable on IIS/Windows is to use an Isapi Filter - as documented at http://neosmart.net/blog/archives/291 . The various steps mentioned below *completely* fail when a rewrite engine is employed, since IIS will *never* return a non-existent path (i.e. the actual pretty-URI used) via its server variables.

This also applies to accessing index.php via a folder.
For instance, calls made to /folder/ will appear as /folder/index.php and not /folder/.

The fix is to use the ISAPI filter provided at http://neosmart.net/blog/archives/291

You don't have to modify any of the actual scripts once this filter is in place - it automatically intercepts calls to REQUEST_URI and replaces them with the actual user-entered path.
me at tommygeorge dot com
09-Nov-2006 04:59
I'm sure this is elsewhere, but since 'chris dot chaudruc at gmail dot com' posted his example, I thought I would share a quick function I use to force HTTPS protocol on a page, without having to know the scripts name...

<?php
function ForceHTTPS()
{
   if(
$_SERVER['HTTPS'] != "on"
   {
      
$new_url = "https://" . $_SERVER['SERVER_NAME'] . $_SERVER['REQUEST_URI'];
      
header("Location: $new_url");
       exit;
   }
}
?>

Correct me if part of this doesn't work right. I've always used *nix based servers for PHP, so I might not be aware of certain windows limitations. Thanks.
Uili - e-info(at)tunenami.com
25-Oct-2006 10:34
Andy Staudacher may have addressed this in his bug fix but just for clarifacation when reading a cookie $_COOKIE reads only the most accurate domain including sub domain. If you have cookies for .bar.com and foo.bar.com and the user is at foo.bar.com $_COOKIE only returns the cookie data from foo.bar.com but if the user is at www.bar.com the data from .bar.com will be read if there is no cookie for www.bar.com.
dlyaza aT yahoo DOT com
22-Oct-2006 07:33
Get Real IP Address; If some one Know More than below, let us to see

if (getenv('HTTP_CLIENT_IP')) {
$IP = getenv('HTTP_CLIENT_IP');
}
elseif (getenv('HTTP_X_FORWARDED_FOR')) {
$IP = getenv('HTTP_X_FORWARDED_FOR');
}
elseif (getenv('HTTP_X_FORWARDED')) {
$IP = getenv('HTTP_X_FORWARDED');
}
elseif (getenv('HTTP_FORWARDED_FOR')) {
$IP = getenv('HTTP_FORWARDED_FOR');
}
elseif (getenv('HTTP_FORWARDED')) {
$IP = getenv('HTTP_FORWARDED');
}
else {
$IP = $_SERVER['REMOTE_ADDR'];
}
seanhickey at gmail dot com
20-Sep-2006 09:46
Note that class objects will not be in the $GLOBALS array until *after* the classe's constructor returns.

<?php
class A
{
   public function
__construct()
   {
      
var_dump($GLOBALS);
   }
}

$a = new A;
var_dump($GLOBALS);
?>

The first var_dump() inside the __construct() method will not contain the value of $a, while the second one will.
Alexander Hars
19-Sep-2006 09:16
If you want to use a form with multiple checkboxes (e.g. one per row) and assign the same name to each checkbox then the name needs to end with []. This tells PHP to put all checked values into an array variable.
For example:
<input type="checkbox" name="id[]" value="value_1">
<input type="checkbox" name="id[]" value="value_2">
..
<input type="checkbox" name="id[]" value="value_x">

You can now retrieve all values by using:
   $values = $_POST['id'];

If the name does not end with [], then only a single value will be available via the $_POST variable even if the user checks several checkboxes.
trevor
08-Aug-2006 05:49
I needed to do the exact same thing as jwl007 (sort by clicking links) but I needed it to append the variable to the query string if it didn't already exist. Here's the function I'm using:

<?php
function setGetVar($var, $val){
  
$request_uri = $_SERVER["REQUEST_URI"];
   if(
strstr($request_uri, $var)) {
       return
preg_replace("/$var=[\\d\\w]*/", "$var=$val", $request_uri);
   } elseif(
strstr($request_uri, "?")) {
       return
$request_uri . "&" . $var . "=" . $val;
   } else {
       return
$request_uri . "?" . $var . "=" . $val;
   }
}
?>

<a href="<?php echo setGetVar("orderby", "lname"); ?>">Sort by Last Name</a>
<a href="<?php echo setGetVar("orderby", "fname"); ?>">Sort by First Name</a>
jmurphy at hsdirect dot co dot uk
26-Jul-2006 02:17
As above the $_SERVER['request_uri']

is replaced in windows iis with

$_SERVER['script_name']
jameslporter at gmail dot com
05-May-2006 07:19
Refer to CanonicalName if you are not getting the ServerName in the $_SERVER[SERVER_NAME] variable....This was a pain to figure out for me...now it works as expected by turning canonical naming on.

http://www.apacheref.com/ref/http_core/UseCanonicalName.html
tchamp
26-Apr-2006 02:24
Be careful with HTTP_HOST behind a proxy server.  Use these instead.
[HTTP_X_FORWARDED_FOR]
[HTTP_X_FORWARDED_HOST]
[HTTP_X_FORWARDED_SERVER]

In my situation, I used [HTTP_X_FORWARDED_SERVER] in place of [HTTP_HOST] in order get the machine and hostname (www.myurl.com)
Ben XO
14-Apr-2006 01:18
So you have an application in your web space, with a URL such as this:

http://<host>/<installation_path>/

and pages such as

http://<host>/<installation_path>/subfolder1/subfolder2/page.php

You have a file called config.php in <installation_path> which is include()d by all pages (in subfolders or not).

How to work out <installation_path> without hard-coding it into a config file?

<?php

// this is config.php, and it is in <installation_path>
// it is included by <installation_path>/page.php
// it is included by <installation_path>/subfolder/page2.php
// etc

$_REAL_SCRIPT_DIR = realpath(dirname($_SERVER['SCRIPT_FILENAME'])); // filesystem path of this page's directory (page.php)
$_REAL_BASE_DIR = realpath(dirname(__FILE__)); // filesystem path of this file's directory (config.php)
$_MY_PATH_PART = substr( $_REAL_SCRIPT_DIR, strlen($_REAL_BASE_DIR)); // just the subfolder part between <installation_path> and the page

$INSTALLATION_PATH = $_MY_PATH_PART
  
? substr( dirname($_SERVER['SCRIPT_NAME']), 0, -strlen($_MY_PATH_PART) )
   :
dirname($_SERVER['SCRIPT_NAME'])
;
// we subtract the subfolder part from the end of <installation_path>, leaving us with just <installation_path> :)

?>
todd dot kisov at yahoo dot com
03-Apr-2006 09:11
To convert query string parameter values ($_GET, $_REQUEST), which include escaped Unicode values resulting from applying the JavaScript "escape" function to a Unicode string (%uNNNN%uNNNN%uNNNN) fast and simple is to use PECL JSON extension:

function JavaScript_Unicode_URL_2_Str($js_uni_str) {
       $res = preg_replace('/%u([[:alnum:]]{4})/', '\\u\1', $js_uni_str);
       $res = str_replace('"', '\"', $res); // if in str "
       $res = json_decode('["'.$res.'"]'); // JavaScrip array with string element
       $res = $res[0];
       $res = iconv('UTF-8', ini_get('default_charset'), $res);
       return $res;
   }
01-Apr-2006 05:56
I was unable to convince my hosting company to change their installation of PHP and therefore had to find my own way to computer $_SERVER["DOCUMENT_ROOT"].  I eventually settled on the following, which is a combination of earlier notes (with some typos corrected):

<?php
if ( ! isset($_SERVER['DOCUMENT_ROOT'] ) )
 
$_SERVER['DOCUMENT_ROOT'] = str_replace( '\\', '/', substr(
  
$_SERVER['SCRIPT_FILENAME'], 0, 0-strlen($_SERVER['PHP_SELF']) ) );
?>
mjs at beebo dot org
30-Mar-2006 09:24
Note that PHP_SELF will not be equal to REQUEST_URI under Apache if mod_rewrite has been used to move one URL to another--PHP_SELF will contain the rewritten address, and REQUEST_URI will contain the URL the user sees in their browser.
adam3000 at gmail dot com
15-Mar-2006 06:30
I was trying to find an alternative to $_SERVER['REQUEST_URI'] for a Windows NT set up and the ones below didn't really work for me so here's my solution using eustf at hotmail dot com's suggestion of $_SERVER['PHP_SELF']:

// if 'REQUEST_URI' isn't available then ...
if(!isset($_SERVER['REQUEST_URI'])) {
  
   // ... set my own request url and ...
   $temp_request_url = $_SERVER['PHP_SELF'];
  
   // ... test for and add url variables to my request url ...
   if (isset($HTTP_SERVER_VARS['QUERY_STRING'])) {
       $temp_request_url .= (strpos($updateGoTo, '?')) ? "&" : "?";
       $temp_request_url .= $HTTP_SERVER_VARS['QUERY_STRING'];
       }

} else {
   // ... otherwise use the regular 'REQUEST_URI'
   $temp_request_url = $_SERVER['REQUEST_URI'];
}
Aardvark
07-Mar-2006 09:35
$_GET may not handle query string parameter values which include escaped Unicode values resulting from applying the JavaScript "escape" function to a Unicode string.
To handle this the query parameter value can be obtained  using a function such as:

function getQueryParameter ($strParam) {
  $aParamList = explode('&', $_SERVER['QUERY_STRING']);
  $i = 0;
  while ($i < count($aParamList)) {
   $aParam = split('=', $aParamList[$i]);
   if ($strParam == $aParam[0]) {
     return $aParam[1];
   }
  }
  return "";
}

or by directly building an array or query string values and then processing the parameter string using a function such as the "unescape" function which can be found at http://www.kanolife.com/escape/2006/03/unicode-url-escapes-in-php.html (or http://www.kanolife.com/escape/ for related info).
justin dot (nospam)george at gmail dot com
28-Feb-2006 08:00
Note that it's a very, very bad idea to append to global variables in a loop, unless you really, really mean to do so in a global context. I just a while ago hung my server with a snippet of code like this:

<?php
$host 
= $_SERVER['HTTP_HOST'];
$uri  = rtrim($_SERVER['PHP_SELF'], "/\\");

  
$GLOBALS['SITE_ROOT'] = "http://$host$uri";

while (
$i < somenumber)
readfile($GLOBALS['SITE_ROOT'] = $GLOBALS['SITE_ROOT'] . '/this/file.php');
$i++
}
?>

While it is an entertaining and unusual method of creating very long URLs and breaking servers, it's a pretty awesomely bad idea

(Especially considering that the script in question ran concurrently with others of it's type, so the value in $GLOBALS['SITE_ROOT'] was unknown.)
nathan
22-Feb-2006 04:05
Also on using IPs to look up country & city, note that what you get might not be entirely accurate.  If their ISP is based in a different city or province/state, the IPs may be owned by the head office, and used across several areas. 
You also have rarer situations where they might be SSHed into another server, on the road, at work, at a friend's...  It's a nice idea, but as the example code shows, it should only be used to set defaults.
geza at turigeza dot com
11-Feb-2006 01:13
Above the manual says

'$_REQUEST is an associative array consisting of the contents of $_GET, $_POST, and $_COOKIE.'
However
$_REQUEST doesn't always contain the same elements as

$_GET+$_POST+$_REQUEST;

Basically if you add an element to the $_POST array that element does not automatically get added to REQUEST as well. It's easy to understand why :)

<?php
$_POST
['geza'] = 'geza';
$_GET['bela'] = 'bela';

echo
'<pre>';
print_r($_POST);
print_r($_GET);
print_r($_REQUEST);
echo
'</pre>';
?>

will output this
Array
(
   [geza] => geza
)
Array
(
   [bela] => bela
)
Array
(
)
marsh at NOSPAM-TAKETHATSPAMMER dot uri
20-Jan-2006 04:05
The solution advanced by info at meshkaat dot com does not work correctly on machines with IIS configured to use
a virtual directory as the launch point. The address strings for $_SERVER['SCRIPT_FILENAME'] and $_SERVER['PHP_SELF'] will not necessarily have the same name for the highest level directory in $_SERVER['PHP_SELF'], and therefore this solution will not return the proper value.
marsh at NOSPAM-TAKETHATSPAMMER dot uri dot edu
12-Jan-2006 03:57
Under Windows XP SP2 and IIS, $_SERVER('x') returns a path using forward slash '/' as the separator, where x is:

     PHP_SELF, SCRIPT_NAME

These arguments, however, all return a path using backward slash, '\' as the separator:

  __FILE__, SCRIPT_FILENAME, and DOCUMENT_ROOT (if you use one of the methods mentioned previously).

Also note that if the name of the last directory in the document root includes a space, the methods described above for setting DOCUMENT_ROOT will return a value that drops the everything past the space.
Andy Staudacher, gmx.ch add ast before @
20-Dec-2005 01:02
The following code is licensed under the GPL and it is from the gallery.menalto.com project.
<?php
  
/**
     * Fix the superglobal $_COOKIE to conform with RFC 2965
     *
     * We don't use $_COOKIE[$cookiename], because it doesn't conform to RFC 2965 (the
     * cookie standard), i.e. in $_COOKIE, we don't get the cookie with the most specific path for
     * a given cookie name, we get the cookie with the least specific cookie path.
     * This function does it exactly the other way around, to a) fix our cookie/login problems and
     * to b) conform with the RFC.
     * The PHP bug was already fixed in spring 2005, but we will have to deal with broken PHP
     * versions for a long time. See http://bugs.php.net/bug.php?id=32802.
     *
     * Fixes also another PHP cookie bug. PHP doesn't expect the cookie header to have
     * quoted-strings, but they are perfectly legal according to RFC 2965.
     *
     * The third bug fixed here is an MS Internet Explorer (IE) bug. When using default cookie
     * domains (no leading dot, don't set the domain in set-cookie), IE is supposed to return only
     * cookies that have the exact request-host as their domain.
     * Example: Cookies stored in the browser with cookie domains: .example.com, .www.example.com,
     *          example.com, www.example.com
     *          The request-host is www.example.com. Thus, IE should return all those cookies but
     *          the example.com cookie, because it's a default domain cookie and it doesn't match
     *          exactly the request-host. But IE returns the example.com cookie too.
     * As MS decided that it returns the cookie with the best domain-match first (unspecified in
     * RFC 2965), this wouldn't be a problem if PHP didn't select the last cookie in the
     * HTTP_COOKIE header. But with fixCookieVars(), this case is also fixed.
     *
     * This function reevaluates the HTTP Cookie header and populates $_COOKIE with the correct
     * cookies. We fix only non-array and non '[', ']' containing cookies for simplicity. To fix
     * our login problem, we'd have to fix only the GALLERYSID cookie anyway.
     *
     * @param boolean force the reevaluation of the HTTP header string Cookie
     * @param boolean unset static variable for testability
     */
  
function fixCookieVars($force=false, $unset=false)
?>
The source code can be found at:
http://cvs.sourceforge.net/viewcvs.py/gallery/gallery2/
modules/core/classes/GalleryUtilities.class?rev=1.146&view=markup
info at meshkaat dot com
06-Dec-2005 01:03
How to get $_SERVER["DOCUMENT_ROOT"] on IIS :

if(!isset($_SERVER["DOCUMENT_ROOT"]))
{$_SERVER["DOCUMENT_ROOT"]=substr($_SERVER['SCRIPT_FILENAME'] , 0 , -strlen($_SERVER['PHP_SELF'])+1 );
}

it simply works!
chris at vault5 dot com
30-Nov-2005 03:17
Since $_SERVER['DOCUMENT_ROOT'] is not always present, the following will provide it where $_SERVER dosen't.

<?php
function resolveDocumentRoot() {
  
$current_script = dirname($_SERVER['SCRIPT_NAME']);
  
$current_path  = dirname($_SERVER['SCRIPT_FILENAME']);
  
  
/* work out how many folders we are away from document_root
       by working out how many folders deep we are from the url.
       this isn't fool proof */
  
$adjust = explode("/", $current_script);
  
$adjust = count($adjust)-1;
  
  
/* move up the path with ../ */
  
$traverse = str_repeat("../", $adjust);
  
$adjusted_path = sprintf("%s/%s", $current_path, $traverse);

  
/* real path expands the ../'s to the correct folder names */
  
return realpath($adjusted_path);   
}

?>

It counts the number of folders down the path we are in the URL, then moves that number of folders up the current path... end result should be the document root :)

It wont work with virtual folders or in any situation where the folder in the URL dosen't map to a real folder on the disk (like when using rewrites).
lorenpr at gmail dot com
01-Nov-2005 11:04
Here's a simple function that has proven reliable for me in checking if a user has refreshed the current page on a website.

function pageRefreshed()
{
  if($_SERVER['HTTP_CACHE_CONTROL'] == 'max-age=0')
     return true;

   return false;
}
webmaster at eclipse dot org
11-Oct-2005 03:01
In response to tobias at net-clipping dot de

It is not an Apache bug.  Please read http://httpd.apache.org/docs/2.1/mod/core.html#errordocument carefully (2.1 version here, 2.0 and 1.x is similar). 

In short, if your ErrorDocument start with http:// Apache sends a redirect (302) to the error document, hence losing your original referer. If your ErrorDocument points to a relative path, 404 is maintained and so are your variables.

From the Apache manual:

"Note that when you specify an ErrorDocument  that points to a remote URL (ie. anything with a method such as http in front of it), Apache will send a redirect to the client to tell it where to find the document, even if the document ends up being on the same server. This has several implications, the most important being that the client will not receive the original error status code, but instead will receive a redirect status code. This in turn can confuse web robots and other clients which try to determine if a URL is valid using the status code. In addition, if you use a remote URL in an ErrorDocument 401, the client will not know to prompt the user for a password since it will not receive the 401 status code. Therefore, if you use an ErrorDocument 401 directive then it must refer to a local document."

D.
drew dot griffiths at clare dot net
30-Sep-2005 03:51
Re: You can take advantage of 404 error to an usable redirection using REQUEST_URI ...

Whilst this is effective, a line in the .htaccess such as:

RewriteEngine On
RewriteRule ^profiles/([A-Za-z0-9-]+) showprofile.php?profile=$1 [L,NC,QSA]

will throw the requested profile in a variable $profile to the showprofile.php page. 

You can further enhance the url (e.g http://servername/profiles/Jerry/homeaddress/index.htm) and the second variable value homeaddress becomes available in $url_array[3] when used below $url_array=explode("/",$_SERVER['REQUEST_URI']); 

Hope this helps - Works well for me

Drew
jeromenelson at gmail dot com
19-Sep-2005 10:56
You can take advantage of 404 error to an usable redirection using REQUEST_URI ...

For example the following program can retrieve the information for the 'search_string', for a given URI:  http://servername/profiles/search_string, even though there's no such path.
Do the following steps..

Step 1: Edit Apache config:  set
       ErrorDocument 404 "/missing.php" 
Step 2: Write the missing.php as follows ...

<?
$mainPath
= "/profiles/";                                      // Example: http://servername/profiles/search_string
$mpLength = strlen( $mainPath  );                               
$request_uri = $_SERVER['REQUEST_URI'];

if (
$mainPath != substr($request_uri,0,$mpLength) ) {          // Check if the given URI is valid
  
echo "404 Page Not Found !";
   exit();
}

$name = substr ($request_uri , $mpLength ) ;                    // Extract the string to be searched

echo "You have searched for the profile of Mr. $name";

/** Here you can write the code to retrieve and display
     the $name's  information from the database
*/
?>

Step 3: Now try http://servername/profiles/Jerry
   (of course, there shouldn't be a file/folder in the server like "DOCROOT/profiles/Jerry" )

     output: You have searched for the profile of Mr. Jerry

God Bless You!
Angelina Bell
04-Aug-2005 03:55
Warning:
$_SERVER['PHP_SELF'] and $_SERVER['SCRIPT_NAME'] may not always be set correctly.
Some web hosts implement php as a CGI in such a way that they can turn it on or off for each virtual domain.  Several $_SERVER and $_ENV variable values may be incorrect for documents in subdirectory subdomains of these virtual domains.

An include-file function or constant, instead of PHP_SELF or some other predefined variable throughout a website, will make it easier to "fix" an entire website in case something changes.
<?php
function true_url_path() {
// Pick the predefined variable that works on your server
    
return $_ENV['SCRIPT_URL'];
}
?>
Or
<?php
// Pick the predefined variable that works on your server
define("TRUE_URL_PATH", $_ENV['SCRIPT_URL']);
?>
Gregory Boshoff
31-Jul-2005 09:41
$_SERVER['QUERY_STRING']

Does not contain XHTML 1.1 compliant ampersands i.e. &amp;

So you will need to do something like this if you are to use $_SERVER['QUERY_STRING'] in URL's.

//  XHTML 1.1 compliant ampersands
$_SERVER['QUERY_STRING'] =
str_replace(array('&amp;', '&'), array('&', '&amp;'),
$_SERVER['QUERY_STRING']);
New York PHP
24-Jul-2005 01:59
Warning: $_SERVER['PHP_SELF'] can include arbitrary user input. The documentation should be updated to reflect this.

The request "http://example.com/info.php/attack%20here" will run /info.php, but in Apache $_SERVER['PHP_SELF'] will equal "/info.php/attack here". This is a feature, but it means that PHP_SELF must be treated as user input.

The attack string could contain urlencoded HTML and JavaScript (cross-site scripting) or it could contain urlencoded linebreaks (HTTP response-splitting).

The use of $_SERVER['SCRIPT_NAME'] is recommended instead.
eustf at hotmail dot com
21-Jul-2005 03:05
REQUEST_URI not defined on Windows XP and IIS 5.1
I have seen different script on the web and in this list but they don't work fully. This one seems to work:

if(!isset($_SERVER['REQUEST_URI'])) {
  $arr = explode("/", $_SERVER['PHP_SELF']);
  $_SERVER['REQUEST_URI'] = "/" . $arr[count($arr)-1];
  if ($_SERVER['argv'][0]!="")
   $_SERVER['REQUEST_URI'] .= "?" . $_SERVER['argv'][0];
}
daniel at softel dot jp
16-Jul-2005 06:43
Note that $php_errormsg may contain a newline character. This can be problematic if you are trying to output it with a JavaScript "alert()" for example.
andy dot gajetzki at gmail dot com
06-Jul-2005 01:22
I wanted to be able to embed a variable in the path. This is useful when, for example, images are rendered on the fly and you would like them to have different urls.

Here is an illustration:

www.somesite.com/image.php/IMAGETEXTHERE

This would return an image with the text after "image.php/" contained in it.

I could not recall the name of this feature, so I made a work-around in PHP...

<?       
      
function getPathVariables() {
      
$sPathPS = $_SERVER[PHP_SELF];
      
$sPathFS = __FILE__;

      
$aPathPS = array_reverse(explode("/", $sPathPS));
      
$aPathFS = array_reverse(explode("/", $sPathFS));

      
$aImageArgs = array();
      
$x = 0;

       while (
$aPathPS[$x] != $aPathFS[$x] && $aPathPS[$x] != $aPathFS[0] ) {
              
array_unshift($aImageArgs, $aPathPS[$x])        ;
              
$x++;
       }
       return
$aImageArgs;

}
?>

This function will return an array containing each "/" delimited portion of the path after the script name itself.
notes at arbee dot co dot uk
27-Jun-2005 02:14
Note that $_SERVER['QUERY_STRING'] behaves differently under IIS/Apache.

In Apache (at least on Windows) it is ALWAYS set - if no query string was specified in the URL, $_SERVER['QUERY_STRING'] is initialised as an empty string.

In IIS, if no query string is included in the URL, $_SERVER['QUERY_STRING'] is NOT SET, so trying to access it without checking for its existence will generate notices.
koerner-familie at t-online dot de
21-Jun-2005 01:52
If you want to make a copy of $BLOBALS (e.g. to test whether which tariables were changed during script-runtime,
<?php $___debug_var_dump = $GLOBALS; ?>
will _NOT_ make a copy in PHP4 (tested with 4.3.11). Use
<?php $___debug_var_dump = array_merge($GLOBALS, array()); ?> instead, but ONLY for testing purpose.
Best regards, Peter
purplebz at hotmail dot com
19-Jun-2005 08:35
How to get $_SERVER['REQUEST_URI'] on IIS (WinXP):

if ( empty($_SERVER['REQUEST_URI']) ) {
   $arr = explode("/", $_SERVER['PHP_SELF']);
   $_SERVER['REQUEST_URI'] = $arr[count($arr)-1];
}
xangelusx at hotmail dot com
13-Jun-2005 08:03
A note about the QUERY_STRING variable when using IIS:

I have found that IIS does not handle large query strings gracefully when passed from PHP. In addition to truncating them to around 1024 kb, I have seen IIS actually add data from other server variables to the end of the truncated data.

This occurred on Windows 2000 server running IIS 5.0 and PHP 4.3.8.  The problem did not occur when handled by Apache, even on another Windows server.

Note: I realize passing this much data is best accomplished using the POST method, which would avoid this problem all together. I'm merely detailing a problem that I came across.

I have created a page that includes the (very long) query string that was used and some of the results that I saw while testing. It can be viewed at http://www.csb7.com/test/php_iis_qs_limit/. I didn't want to include it here as it would stretch the page out significantly.

~Chris Bloom
mfyahya at gmail dot com
07-Jun-2005 01:33
If you use Apache's redirection features for custom error pages or whatever, the following Apache's REDIRECT variables are also available in $_SERVER:
$_SERVER['REDIRECT_UNIQUE_ID]'
$_SERVER['REDIRECT_SCRIPT_URL]'
$_SERVER['REDIRECT_SCRIPT_URI]'
$_SERVER['REDIRECT_SITE_ROOT]'
$_SERVER['REDIRECT_SITE_HTMLROOT]'
$_SERVER['REDIRECT_SITE_CGIROOT]'
$_SERVER['REDIRECT_STATUS]'
$_SERVER['REDIRECT_QUERY_STRING]'
$_SERVER['REDIRECT_URL]'

I'm not sure if this is a complete list though
mp at wds-tech dot de
02-Jun-2005 07:12
Also aviable is the $_SERVER['SERVER_ADDR'] which returns the current IP of the server the script is running on.
webKami (et) AKDomains.com
24-May-2005 06:47
PHP Secure Class to prevent XSS Attacks

Although this is not bullet proof but it would give you an idea on how to filter incoming data.

Copyleft : LGPL
Idea by: phpsec GROUP @ PHP|arch

Coded By: webKami

For those who are new to PHP and just heard of XSS attacks, this is the basic rule.

"NEVER EVER TRUST EXTERNAL DATA"

For this purpose I have coded a class that can be used to filter all external data, from POST, GET, COOKIE and even your own arrays.

An example is that if you need only integers from a certain parameter just request for integer
e.g. getVarInt("id")

You can even tell it to give you a default value if param is not set, so that your page would not FAIL in case of a NULL value
e.g. getVarInt("id",1)

You can also fetch data from a param array, like a set of colors
e.g. getVarInt("colors",0,0)
e.g. getVarInt("colors",0,1)

Get these variables in a loop limited by the count of that array's elements
e.g. getVarCount("colors")

The complete code of class and its usage can be found here

http://www.webkami.com/programming/php/php-secure-class-to-avoid-xss

I am posting the usage below.

<?

//for url variables
$req = new requestGet();
echo
"Int:".$req->getVarInt("id")."<br />";
echo
"Alpha:".$req->getVarAlpha("name",4)."<br />";

//for form variables
$req = new requestPost();
echo
"Int:".$req->getVarInt("id")."<br />";
echo
"Alpha:".$req->getVarAlpha("name",4)."<br />";

//for cookies
$req = new requestCookie();
echo
"Int:".$req->getVarInt("id")."<br />";
echo
"Alpha:".$req->getVarAlpha("name",4)."<br />";

//for your own variables, set your values to an item in an array and you can modify the array

$filter["id"]=4;
$filter["name"]="Ali";
$req = new requestFilter($filter);
echo
"Int:".$req->getVarInt("id")."<br />";
echo
"Alpha:".$req->getVarAlpha("name",4)."<br />";

?>
JM
17-May-2005 08:08
The $_SERVER['PHP_AUTH_*'] variables are not available in safe mode.  See http://www.php.net/features.http-auth
www dot php dot net at webdevelopers dot cz
12-May-2005 01:01
Simple function that selects "best" language for the user from the list of available languages:

function chooseLang($availableLangs) {
   $pref=array();
   foreach(split(',', $_SERVER["HTTP_ACCEPT_LANGUAGE"]) as $lang) {
       if (preg_match('/^([a-z]+).*?(?:;q=([0-9.]+))?/i', $lang.';q=1.0', $split)) {
           $pref[sprintf("%f%d", $split[2], rand(0,9999))]=strtolower($split[1]);       
       }
   }
   krsort($pref);
   return array_shift(array_merge(array_intersect($pref, $availableLangs), $availableLangs));
}
 
echo 'BESTLANG: '.chooseLang(array('cs', 'sk', 'ru', 'en'));

Daniel "elixon" Sevcik
exaton at free dot fr
06-May-2005 06:23
With the arrival of the Google Web Accelerator, the problem of keeping track of users through $_SERVER['REMOTE_ADDR'] (for a much shorter while than with cookies) has reared its ugly head anew.

For those confronted with this issue, remember that Google implements the $_SERVER['HTTP_X_FORWARDED_FOR'] header giving the IP address of the connection that it proxies.

Hope this helps...
inbox at tanasity dot com
13-Apr-2005 01:23
Under Windows 2000, running IIS and PHP 4.3.10, $_SERVER['SCRIPT_NAME'] is not available, however $_SERVER['SCRIPT_FILENAME'] is present and seems to contain the same information.
javalizard at mac dot com
10-Apr-2005 11:02
My web host server will give my php the user preferred languages out over the order.  This means that I had to write a function for ordering the languages based upon their "q" value (rank from 1..0, 1 being the most preferred).  If you want an ordered list of user preferred languages use this function:

<?php
function orderedLanguages()
{
  
$languages = split(",", $_SERVER['HTTP_ACCEPT_LANGUAGE'] );
  
$lang_q = Array();
   foreach(
$languages as $aLang ) {
      
$lang_array = split(";q=", trim( $aLang ) );
      
$lang = trim( $lang_array[0] );
       if( !isset(
$lang_array[1] ) )
          
$q = 1;
       else
          
$q = trim($lang_array[1]);
      
$lang_q["$lang"] = (float)$q;
   }
  
arsort($lang_q);
  
//extra code for making the languages key indexed
  
$i = 0;
  
$lang_index = Array();
   foreach(
$lang_q as $lang => $q) {
  
//    $lang_q[$i] = $lang; //add to the same array the index key/language
      
$lang_index[$i] = $lang; //add to a new array the index key/language
      
$i++;
   }
  
  
//return $lang_index; // uncomment for returning array with keys={0..n-1}, values={most..least preferred}
  
return $lang_q;
}

?>

While you can't reference the key by number, You can use foreach to pull elements.  This will be in order.  So getting the key with array_keys should work in the preferred order too.  I've added a few extra lines of commented code for reordering the array into one(s) that reference the language by number (if you need it)  :D
skrollster
26-Mar-2005 04:36
$_SERVER["REMOTE_USER"] and $_SERVER['PHP_AUTH_USER'] is the same variable i think..
anonymous
04-Mar-2005 10:12
I don't see the $_SERVER["REMOTE_USER"] listed in this document.
This displays the username used to login using .htaccess.
28-Feb-2005 02:41
Matt Johnson says that one should never urldecode() $_GET data. This is incorrect.

If magic_quotes_gpc is turned off in php.ini, then you *do* need to urldecode() $_GET data.

Having magic_quotes_gpc turned off is considered good practise.
17-Feb-2005 11:30
grlprgrmmr wrote:

you can use these to reconstructed the current page url.

<?php

echo 'http';
if(
$_SERVER['HTTPS']=='on'){echo 's';}
echo
'://'.$_SERVER['SERVER_PORT'].$_SERVER['SCRIPT_NAME'];
if(
$_SERVER['QUERY_STRING']>' '){echo '?'.$_SERVER['QUERY_STRING'];}

?>
______________

the $_SERVER['SERVER_PORT'] part should be changed to $_SERVER['HTTP_HOST']
Gregory Boshoff
14-Feb-2005 12:19
The Environment variable $ENV is useful for coding portable platform specific application constants.

// Define a Windows or else Linux root directory path
$_ENV['OS'] == 'Windows_NT' ? $path = 'L:\\www\\' : $path = ' /var/www/';

define('PATH', $path);

echo PATH;
magotes[at]netcabo.pt
12-Feb-2005 03:09
Sorry if this is old news to some, but it might not be obvious at a first glance:

If you are using $_SERVER['remote_addr'] as a way to keep track of a logged-in user (this can be useful to avoid several types of hacking), remember that it might not be the user's actual IP address!

I was trying to implement a login feature that used this, storing the IP into a DB. It went smoothly while on a LAN, but wrecked havoc when accepting outter connections.
grlprgrmmr uses gmail
10-Feb-2005 07:05
you can use these to reconstructed the current page url.

<?php

echo 'http';
if(
$_SERVER['HTTPS']=='on'){echo 's';}
echo
'://'.$_SERVER['SERVER_PORT'].$_SERVER['SCRIPT_NAME'];
if(
$_SERVER['QUERY_STRING']>' '){echo '?'.$_SERVER['QUERY_STRING'];}

?>

If $_SERVER['HTTPS']=='on' does not work for you,
try $_SERVER['SERVER_PORT']==443 (or whatever secure port is used)
JSP001
27-Jan-2005 10:15
Hi dotpointer,

I am new to php but I suggest a little modification of your script. Tell me what you think of it :

function getThisFile() {

[...]
   /* last resort __FILE__ */
   } else {
       $strScript = __FILE__;
   }
[...]
}

Thanks for this great function, I'll use it for my project !

Regards
niles AT atheos DOT net
26-Jan-2005 08:51
If your having problems returning $_SERVER variables using apache, be sure you enable:

ExtendedStatus On

in your httpd.conf file.

If it's off, then things like $_SERVER['HTTP_HOST'] won't be present.
marcus at lastcraft dot com
24-Jan-2005 12:02
The variable $php_errormsg is not populated if you have XDebug running.
arjini at gmail dot com
19-Jan-2005 12:29
Driven crazy by the lack of consistency with $_SERVER across installations? Check out this chart:

http://www.koivi.com/apache-iis-php-server-array.php
roy dot rico at gmail dot com
18-Jan-2005 09:48
if you are trying to use $php_errormsg, it acts more like a function than it does a variable.

example

   echo "<h1>";
   $php_errormsg;
   echo "</h1>";

will output:

   <h1>[the php error]<h1>

however, this command

   echo "<h1>" . $php_errormsg . "</h1>";

should produce the same thing, yet it produces

   [the php error]<h1></h1>

not sure if this is a "feature" or a "bug"
dotpointer
09-Jan-2005 09:26
Running Xitami in Windows 2000 and PHP 4.3.7, nor PHP_SELF or SCRIPT_FILENAME is not availiable. Trying SCRIPT_NAME instead. Here is a function that returns the filename of a script without slashes. Good for use in HTML FORM ACTION=""-arguments...

function getThisFile() {

 /* try to use PHP_SELF first... */
 if (!empty($_SERVER['PHP_SELF'])) {
  $strScript = $_SERVER['PHP_SELF'];
 /* otherwise, try SCRIPT_NAME */
 } else if (!empty($_SERVER['SCRIPT_NAME'])) {
  $strScript = @$_SERVER['SCRIPT_NAME'];
 /* last resort - quit out and return nothing */
 } else {
  return null;
 }

 /* fint last frontslash in filename */
 $intLastSlash = strrpos($strScript, "/");

 /* check if last backslash is more far away in filename */
 if (strrpos($strScript, "\\")>$intLastSlash) {
  /* if so, use the backslash position instead */
  $intLastSlash = strrpos($strScript, "\\");
 }

 /* cut out from the last slash and to the end of the filename */
 return substr($strScript, $intLastSlash+1, strlen($strScript));
}

Tested on PHP 4.3.7/Win32 and PHP 5.0.3/Linux.
You may add more filepaths to the first if-section
to get more chances to catch up the filename if you can.
Matt Johnson
26-Dec-2004 12:50
A reminder: if you are considering using urldecode() on a $_GET variable, DON'T!

Evil PHP:

<?php
# BAD CODE! DO NOT USE!
$term = urldecode($_GET['sterm']);
?>

Good PHP:

<?php
$term
= $_GET['sterm'];
?>

The webserver will arrange for $_GET to have been urldecoded once already by the time it reaches you!

Using urldecode() on $_GET can lead to extreme badness, PARTICULARLY when you are assuming "magic quotes" on GET is protecting you against quoting.

Hint: script.php?sterm=%2527 [...]

PHP "receives" this as %27, which your urldecode() will convert to "'" (the singlequote). This may be CATASTROPHIC when injecting into SQL or some PHP functions relying on escaped quotes -- magic quotes rightly cannot detect this and will not protect you!

This "common error" is one of the underlying causes of the Santy.A worm which affects phpBB < 2.0.11.
mrnopersonality at yahoo dot com
19-Oct-2004 03:13
Nothing about the message-body ...

You can get cookies, session variables, headers, the request-uri , the request method, etc but not the message body. You may want it sometimes when your page is to be requested with the POST method.

Maybe they should have mentioned $HTTP_RAW_POST_DATA or php://stdin
hfuecks at phppatterns dot com
06-Sep-2004 07:21
Using Apache/mod_ssl, there are further environment variables available to check for an SSL connection (can be more useful than $_SERVER['SERVER_PORT']), documented here: http://www.modssl.org/docs/2.8/ssl_reference.html#ToC25

To test whether the client connected with SSL I can use $_SERVER['HTTPS'] e.g (with redirect to secured, current URL);

<?php
if ( !isset($_SERVER['HTTPS']) || strtolower($_SERVER['HTTPS']) != 'on' ) {
  
header ('Location: https://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI']);
   exit();
}
?>
boaz at babylon dot com
30-Aug-2004 02:13
You can add $_SERVER["DOCUMENT_ROOT"] to IIS by editing the Environment Variables of your Windows server (was tested on WinXP SP2).

Right click on My Computer >> Properties >> Advanced.
In the System variables click on 'New' and Type in the name field 'DOCUMENT_ROOT' and in the value field  the path to your IIS document root folder.

Don't forget to restart your Windows (IIS restart won't load the new settings).
david at grant dot org dot uk
12-May-2004 12:34
$_SERVER['DOCUMENT_ROOT'] *is* supported by IIS, although only when running PHP as an ISAPI module.
youdontmeanmuch [at] yahoo.com
06-Apr-2004 04:20
Be carful when using $_SERVER['DOCUMENT_ROOT']; in your applications where you want to distribute them to other people with different server types. It isnt always supported by the webserver (IIS).
mortoray at ecircle-ag dot com
18-Dec-2003 05:32
The RAW / uninterpreted HTTP POst information can be accessed with:
   $GLOBALS['HTTP_RAW_POST_DATA']

This is useful in cases where the post Content-Type is not something PHP understands (such as text/xml).
josh,endquote,com
03-Dec-2003 11:54
Running PHP 4.3 under IIS 5 on Windows XP, there is no $_SERVER['REQUEST_URI'] variable. This seems to fix it:

if(!isset($_SERVER['REQUEST_URI'])) {
   $_SERVER['REQUEST_URI'] = substr($_SERVER['argv'][0], strpos($_SERVER['argv'][0], ';') + 1);
}