What does it influence predefined $ SERVER array?

[toplisek]

What does it influence predefined $_SERVER array and how to read this predefined arrays.

[penders]

Not sure that I completely follow? Many scripts could make use of the $_SERVER array, so changing it could influence any 3rd party scripts you might have - but it won't affect anything outside of your scripts.

<?php echo $_SERVER['DOCUMENT_ROOT']; ?>

<?php 
// Display the entire variable 
print_r($_SERVER); 
?>

[Matthew1980]

Hi there toplisek,

From the manual: $_SERVER [php.net]

A very valuable resource. Hope this is what your referring to.

[EDIT] Sometimes the values in this array are only set if they are in use prime example of this is: $_SERVER['HTTP_X_FORWARDED_FOR']; useful to know if your intending to track IP addresses so that you can inform your users of what IP they are currently logged in from.

And what penders has posted will answer your question as to what is set when you load the page.

Cheers,
MRb

[penders]

And... the values contained in this array can vary from server to server (as it's name suggests). Some servers will not even set certain values, or it might be set differently. Something to bare in mind when writing portable code, particularly between Win/Linux, IIS/Apache.

[toplisek]

Is there some example to do useful track of IP addresses so that I can inform my users of what IP they are currently logged in from.

[Matthew1980]

Hi there toplisek,

function get_ip(){

$ip_address = array();

if (isset($_SERVER['HTTP_X_FORWARDED_FOR']) && strpos($_SERVER['HTTP_X_FORWARDED_FOR'],',')){
$ip_address += explode(',',$_SERVER['HTTP_X_FORWARDED_FOR']);
}
elseif (isset($_SERVER['HTTP_X_FORWARDED_FOR'])){
$ip_address[] = $_SERVER['HTTP_X_FORWARDED_FOR'];
}
$ip_address[] = $_SERVER['REMOTE_ADDR'];

return $ip_address;
}

That's what I use to get users IP, please note that this will only function IF the $_SERVER['HTTP_X_FORWARDED_FOR'] is actually set.

Cheers,
MRb

[toplisek]

Do you have some application example how you meant:
..what IP they are currently logged in from?

[toplisek]

I think this is better to detect IP:
function getRealIpAddr()
{
if (!empty($_SERVER['HTTP_CLIENT_IP'])) //check ip from share internet
{
$ip=$_SERVER['HTTP_CLIENT_IP'];
}
elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) //to check ip is pass from proxy
{
$ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
}
else
{
$ip=$_SERVER['REMOTE_ADDR'];
}
return $ip;
}

[penders]

$ip=$_SERVER['HTTP_X_FORWARDED_FOR'];

It's possible that HTTP_X_FORWARDED_FOR can contain multiple IP addresses, comma separated, depending on whether the user is accessing your site through 1 or more proxy servers.

[toplisek]

You mean all working code is correct:

<?PHP
function getRealIpAddr()
{ $ip_address = array();
if (!empty($_SERVER['HTTP_CLIENT_IP'])) //check ip from share internet
{
$ip_address = $_SERVER['HTTP_CLIENT_IP'];
}
elseif (isset($_SERVER['HTTP_X_FORWARDED_FOR']) && strpos($_SERVER['HTTP_X_FORWARDED_FOR'],','))

//to check ip is pass from proxy
{
$ip_address += explode(',',$_SERVER['HTTP_X_FORWARDED_FOR']);
}
elseif (isset($_SERVER['HTTP_X_FORWARDED_FOR'])){$ip_address[] = $_SERVER['HTTP_X_FORWARDED_FOR'];
}
else
{
$ip_address = $_SERVER['REMOTE_ADDR'];
}
return $ip_address;
}
?>