getenv

Gets the value of an environment variable

&reftitle.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".

&reftitle.parameters;

`varname`

- The variable name.

&reftitle.returnvalues;

Returns the value of the environment variable `varname`, or &false; if the environment variable `varname` does not exist.

&reftitle.examples;

### `getenv` Example

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

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

&reftitle.seealso;

- `putenv`
- `apache_getenv`
- Superglobals