Php/docs/function.getenv
getenv
(PHP 4, PHP 5, PHP 7)
getenv — Gets the value of an environment variable
Description
getenv
( string $varname
[, bool $local_only
= FALSE
] ) : string
getenv ( ) : array
Gets the value of an environment variable.
You can see a list of all the environmental variables by using phpinfo(). Many of these variables are listed within » RFC 3875, specifically section 4.1, "Request Meta-Variables".
Parameters
varname
- The variable name.
local_only
- Set to true to only return local environment variables (set by the operating system or putenv).
Return Values
Returns the value of the environment variable
varname
, or FALSE
if the environment
variable varname
does not exist.
If varname
is omitted, all environment variables are
returned as associative array.
Changelog
Version | Description |
---|---|
7.1.0 | The varname can now be omitted to retrieve an
associative array of all environment variables. |
5.5.38, 5.6.24, 7.0.9 | The local_only parameter has been added.
|
Notes
Warning
If PHP is running in a SAPI such as Fast CGI, this function will
always return the value of an environment variable set by the SAPI,
even if putenv() has been used to set a local
environment variable of the same name. Use the local_only
parameter to return the value of locally-set environment variables.
Examples
Example #1 getenv() Example
<?php// Example use of getenv()$ip = getenv('REMOTE_ADDR');// Or simply use a Superglobal ($_SERVER or $_ENV)$ip = $_SERVER['REMOTE_ADDR'];// Safely get the value of an environment variable, ignoring whether // or not it was set by a SAPI or has been changed with putenv$ip = getenv('REMOTE_ADDR', true) ?: getenv('REMOTE_ADDR')?>
See Also
- putenv() - Sets the value of an environment variable
- apache_getenv() - Get an Apache subprocess_env variable
- Superglobals