(PHP 4, PHP 5)
getenv — Liefert den Wert einer Umgebungsvariable
Liefert den Wert einer Umgebungsvariable.
Eine Liste aller Umgebungsvariablen können Sie über die Funktion phpinfo() anzeigen lassen. Die Bedeutung vieler dieser Variablen können Sie in der » CGI-Spezifikation im Abschnitt über » Umgebungsvariablen nachlesen.
Der Variablenname
Gibt den Wert der Umgebungsvariable varname zurück oder FALSE bei Fehlern.
Beispiel #1 getenv()-Beispiel
<?php
// nutzen Sie getenv() ...
$ip = getenv('REMOTE_ADDR');
// ... oder einfache die superglobalen Arrays ($_SERVER oder $_ENV)
$ip = $_SERVER['REMOTE_ADDR'];
?>
This function is useful (compared to $_SERVER, $_ENV) because it searches $varname key in those array case-insensitive manner.
For example on Windows $_SERVER['Path'] is like you see Capitalized, not 'PATH' as you expected.
So just: <?php getenv('path') ?>
When writing CLI applications, not that any environment variables that are set in your web server config will not be passed through. PHP will pass through system environment variables that are prefixed based off the safe_mode_allowed_env_vars directive in your php.ini
A function returning the remote adress of the visiting browser could look like this:
<?php
function getIPfromXForwarded() {
$ipString=@getenv("HTTP_X_FORWARDED_FOR");
$addr = explode(",",$ipString);
return $addr[sizeof($addr)-1];
}
?>
Note that some adresses are followed by a whitespace and ip2long(getIPfromXForwarded()) would not return the expected result.
Make use of trim() in your scripts, either in the function itself, or the surrounding space of the caller.
Greetings
This is a sample function for checking if your visitor comes from this certain country. This is especially useful for amateur webmasters who don't want to use sql databases.
Sample use of function:
<?php
if(check_coutry('http://www.domain.com/files/philippines.csv') === true)
echo 'You are from the Philippines';
?>
Basically, you'll need CSV (or TXT) which lists the IP ranges of a certain country. Example (excerpt of the philippines.csv only):
58.69.0.0, 58.69.255.255
58.71.0.0, 58.71.127.255
61.9.0.0, 61.9.127.255
61.14.28.0, 61.14.28.63
61.14.41.136, 61.14.41.143
and so on until the end
You may obtain these CSV files in a number of websites out there. Be sure to update these CSV files regularly as these IP ranges change from time to time.
Here is the function:
<?php
function check_country($url_csv){
$curl_handle = curl_init();
curl_setopt($curl_handle, CURLOPT_URL, $url_csv);
curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
$str_fromfile = curl_exec($curl_handle);
curl_close($curl_handle);
$range = explode("\n", $str_fromfile);
$ip_addr = getenv(REMOTE_ADDR); //gets the IP of the visitor
$ip_byte = explode('.', $ip_addr);
$ip_number = (16777216 * (int) $ip_byte[0]) + (65536 * (int) $ip_byte[1]) + (256 * (int) $ip_byte[2]) + ((int) $ip_byte[3]);
for($i = 0; $range[$i] != NULL && $is_positive == NULL; $i++){ // the condition $line[$i] != NULL means that you should not put blank lines before the end of your CSV. The values should start at line 1.
$range[$i] = rtrim(ltrim($range[$i])); //you may remove this if you are sure the CSV doesnt contain whitespaces
$ends_addr = explode(',', $range[$i]); //for CSV (comma-separated values), comma is the separator. You may change this if your TXT uses different separator.
$ends_addr[0] = rtrim($ends_addr[0]); //again, you may remove this if your CSV is free from whitespaces
$ends_addr[1] = ltrim($ends_addr[1]); //yet, again
$start_ip_byte = explode('.', $ends_addr[0]);
$end_ip_byte = explode('.', $ends_addr[1]);
$start_ip_number = (16777216 * (int) $start_ip_byte[0]) + (65536 * (int) $start_ip_byte[1]) + (256 * (int) $start_ip_byte[2]) + ((int) $start_ip_byte[3]);
$end_ip_number = (16777216 * (int) $end_ip_byte[0]) + (65536 * (int) $end_ip_byte[1]) + (256 * (int) $end_ip_byte[2]) + ((int) $end_ip_byte[3]);
if($ip_number >= $start_ip_number && $ip_number <= $end_ip_number)
$is_positive = 1;
}
if($is_positive == 1)
return true;
else
return false;
}
?>
SERVER_NAME is the name defined in the apache configuration.
HTTP_HOST is the host header sent by the client when using the more recent versions of the http protocol.
The function 'getenv' does not work if your Server API is ASAPI (IIS).
So, try to don't use getenv('REMOTE_ADDR'), but $_SERVER["REMOTE_ADDR"].
As you know, getenv('DOCUMENT_ROOT') is useful.
However, under CLI environment(I tend to do quick check
if it works or not), it doesn't work without modified php.ini
file. So I add "export DOCUMENT_ROOT=~" in my .bash_profile.
Be careful using HTTP_X_FORWARDED_FOR in conditional statements collecting the IP address. Sometimes the user's LAN address will get forwarded, which of course is pretty worthless by itself.
Note that some caches seem to send the client-ip header *backwards*. be careful :)
Note that the X-Forwarded for header might contain multiple addresses, comma separated, if the request was forwarded through multiple proxies.
Finally, note that any user can add an X-Forwarded-For header themselves. The header is only good for traceback information, never for authentication. If you use it for traceback, just log the entire X-Forwarded-For header, along with the REMOTE_ADDR.