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[edit] Last updated: Thu, 12 Jan 2012

getenv

(PHP 4, PHP 5)

getenv — Gets the value of an environment variable

Descrierea

string getenv ( string $varname )

Gets the value of an environment variable.

You can see a list of all the environmental variables by using phpinfo(). Many of these variables are listed within » RFC 3875, specifically section 4.1, "Request Meta-Variables".

Parametri

varname: The variable name.

Valorile întoarse

Returns the value of the environment variable varname, or FALSE if the environment variable varname does not exist.

Exemple

Example #1 getenv() Example


<?php
// Example use of getenv()
$ip = getenv('REMOTE_ADDR');

// Or simply use a Superglobal ($_SERVER or $_ENV)
$ip = $_SERVER['REMOTE_ADDR'];
?>

Vedeți de asemenea

putenv() - Sets the value of an environment variable
apache_getenv() - Get an Apache subprocess_env variable
Superglobals

getlastmod

get_required_files

[edit] Last updated: Thu, 12 Jan 2012

add a note User Contributed Notes getenv

php at keith tyler dot com 07-Feb-2012 05:51


All of the notes and examples so far have been strictly CGI.

It should not be understated the usefulness of getenv()/putenv() in CLI as well.



You can pass a number of variables to a CLI script via environment variables, either in Unix/Linux bash/sh with the "VAR='foo'; export $VAR" paradigm, or in Windows with the "set VAR='foo'" paradigm. (Csh users, you're on your own!) getenv("VAR") will retrieve that value from the environment.



We have a system by which we include a file full of putenv() statements storing configuration values that can apply to many different CLI PHP programs. But if we want to override these values, we can use the shell's (or calling application, such as ant) environment variable setting method to do so.



This saves us from having to manage an unmanageable amount of one-off configuration changes per execution via command line arguments; instead we just set the appropriate env var first.

eng.mrkto.com 29-Jul-2010 05:36


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') ?>

chuck dot reeves at gmail dot com 06-May-2010 05:59


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

f dot hartmann2 at gmx dot net 22-Jul-2009 11:42


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

estarapapax at gmail dot com 18-Feb-2009 02:19


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;


}


?>

sam at sambarrow dot com 12-Mar-2008 11:32


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.

renko at <remove>virtual-life dot net 07-Nov-2004 11:40


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"].

kyong 03-Feb-2004 06:06


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.

daman at SPAM_BlockERmralaska dot com 08-Sep-2002 12:37


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.

alex at acid-edge dot net 23-Jul-2002 04:32


Note that some caches seem to send the client-ip header *backwards*. be careful :)

john-php at pc dot xs4all dot nl 15-Aug-2000 12:56


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.

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