Gets the value of an environment variable

get_required_files
getlastmod
PHP Options/Info Functions
PHP Manual

# getenv

(PHP 4, PHP 5)

getenv — Gets the value of an environment variable

### Description

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".

### Parameters

`varname`

  The variable name.

### Return Values

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

### Examples

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'];
?>`

### See Also

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

get_required_files
getlastmod
PHP Options/Info Functions
PHP Manual