Gets the value of an environment variable (original) (raw)

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 ( void ) : array

You can see a list of all the environmental variables by usingphpinfo(). 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 variablevarname, 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() <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>i</mi><mi>p</mi><mo>=</mo><mi>g</mi><mi>e</mi><mi>t</mi><mi>e</mi><mi>n</mi><mi>v</mi><msup><mo stretchy="false">(</mo><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mi>R</mi><mi>E</mi><mi>M</mi><mi>O</mi><mi>T</mi><msub><mi>E</mi><mi>A</mi></msub><mi>D</mi><mi>D</mi><msup><mi>R</mi><mo mathvariant="normal" lspace="0em" rspace="0em">′</mo></msup><mo stretchy="false">)</mo><mo separator="true">;</mo><mi mathvariant="normal">/</mi><mi mathvariant="normal">/</mi><mi>O</mi><mi>r</mi><mi>s</mi><mi>i</mi><mi>m</mi><mi>p</mi><mi>l</mi><mi>y</mi><mi>u</mi><mi>s</mi><mi>e</mi><mi>a</mi><mi>S</mi><mi>u</mi><mi>p</mi><mi>e</mi><mi>r</mi><mi>g</mi><mi>l</mi><mi>o</mi><mi>b</mi><mi>a</mi><mi>l</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">ip = getenv('REMOTE_ADDR');// Or simply use a Superglobal (</annotation></semantics></math>ip=getenv(′REMOTEADDR′);//OrsimplyuseaSuperglobal(_SERVER or $_ENV) <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>i</mi><mi>p</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">ip = </annotation></semantics></math>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') ?>