How to get all client info from website visitors? - networking

Question

I want to collect all the information that we could when someone is visiting a webpage: e.g.:
clients screen resolution: <script type='text/javascript'>document.write(screen.width+'x'+screen.height); </script>
referer: <?php print ($_SERVER['HTTP_REFERER']); ?>
client ip: <?php print ($_SERVER['REMOTE_ADDR']); ?>
user agent: <?php print ($_SERVER['HTTP_USER_AGENT']); ?>
what else is there?

Answer 1

Those are the basic pieces of information. Anything beyond that could be viewed as SpyWare-like and privacy advocates will [justifiably] frown upon it.
The best way to obtain more information from your users is to ask them, make the fields optional, and inform your user of exactly what you will be using the information for. Will you be mailing them a newsletter?
If you plan to eMail them, then you MUST use the "confirmed opt-in" approach -- get their consent (by having them respond to an eMail, keyed with a special-secret-unique number, confirming that they are granting permission for you to send them that newsletter or whatever notifications you plan to send to them) first.
As long as you're up-front about how you plan to use the information, and give the users options to decide how you can use it (these options should all be "you do NOT have permission" by default), you're likely to get more users who are willing to trust you and provide you with better quality information. For those who don't wish to reveal any personal information about themselves, don't waste your time trying to get it because many of them take steps to prevent that and hide anyway (and that is their right).

Answer 2

Get all the information of client's machine with this small PHP:
<?php
foreach($_SERVER as $key => $value){
echo '$_SERVER["'.$key.'"] = '.$value."<br />";
}
?>

Answer 3

The list that is available to PHP is found here.
If you need more details than that, you might want to consider using Browserhawk.

Answer 4

For what end?
Remember that client IP is close to meaningless now. All users coming from the same proxy or same NAT point would have the same client IP. Years go, all of AOL traffic came from just a few proxies, though now actual AOL users may be outnumbered by the proxies :).
If you want to uniquely identify a user, its easy to create a cookie in apache (mod_usertrack) or whatever framework you use. If the person blocks cookies, please respect that and don't try tricks to track them anyway. Or take the lesson of Google, make it so useful, people will choose the utility over cookie worries.
Remember that Javascript runs on the client. Your document.write() will show the info on their webpage, not do anything for your server. You'd want to use Javascript to put this info in a cookie, or store with a form submission if you have any forms.

Answer 5

I like to use something like this:
$log = array(
'ip' => $_SERVER['REMOTE_ADDR'],
're' => $_SERVER['HTTP_REFERER'],
'ag' => $_SERVER['HTTP_USER_AGENT'],
'ts' => date("Y-m-d h:i:s",time())
);
echo json_encode($log);
You can save that string in a file, the JSON is pretty small and is just one line.

Answer 6

phpinfo(32);
Prints a table with the whole extractable information. You can simply copy and paste the variables directly into your php code.
e.g:
_SERVER["GEOIP_COUNTRY_CODE"] AT
would be in php code:
echo $_SERVER["GEOIP_COUNTRY_CODE"];

Answer 7

get all the outputs of $_SERVER variables:
<?php
$test_HTTP_proxy_headers = array('GATEWAY_INTERFACE','SERVER_ADDR','SERVER_NAME','SERVER_SOFTWARE','SERVER_PROTOCOL','REQUEST_METHOD','REQUEST_TIME','REQUEST_TIME_FLOAT','QUERY_STRING','DOCUMENT_ROOT','HTTP_ACCEPT','HTTP_ACCEPT_CHARSET','HTTP_ACCEPT_ENCODING','HTTP_ACCEPT_LANGUAGE','HTTP_CONNECTION','HTTP_HOST','HTTP_REFERER','HTTP_USER_AGENT','HTTPS','REMOTE_ADDR','REMOTE_HOST','REMOTE_PORT','REMOTE_USER','REDIRECT_REMOTE_USER','SCRIPT_FILENAME','SERVER_ADMIN','SERVER_PORT','SERVER_SIGNATURE','PATH_TRANSLATED','SCRIPT_NAME','REQYEST_URI','PHP_AUTH_DIGEST','PHP_AUTH_USER','PHP_AUTH_PW','AUTH_TYPE','PATH_INFO','ORIG_PATH_INFO','GEOIP_COUNTRY_CODE');
foreach($test_HTTP_proxy_headers as $header){
echo $header . ": " . $_SERVER[$header] . "<br/>";
}
?>