putenv

Function name: putenv()

Function Description: This function is used to set the value of an environment variable.

Applicable versions: All versions of PHP

usage:

 bool putenv ( string $setting )

parameter:

• $setting : The environment variable and its value to be set, in the format "variable=value".

Return value:

• Return true if the environment variable is successfully set; otherwise return false.

Example:

 // 示例1：设置环境变量putenv("DB_HOST=localhost"); putenv("DB_USER=root"); putenv("DB_PASS=123456"); // 示例2：获取环境变量$host = getenv("DB_HOST"); $user = getenv("DB_USER"); $pass = getenv("DB_PASS"); echo "DB_HOST: " . $host . "<br>"; echo "DB_USER: " . $user . "<br>"; echo "DB_PASS: " . $pass . "<br>";

In the above example, three environment variables are first set through putenv() function, namely the database host address, user name and password. Then, the values ​​of these environment variables are obtained through getenv() function and output them to the browser.