How to check if php session is already started or not

Question

Hii,

When I have session_start() on this script I sometimes get the error message for "session already started". For that I've put these lines:

if(!isset($_COOKIE["PHPSESSID"]))
{
  session_start();
}

but this time I got this warning message:

Notice: Undefined variable: _SESSION

Is there a better way to check if session has already started?

Answer 1

Hello kartik,

Use session_id(), it returns an empty string if not set. It's more reliable than checking the $_COOKIE.

if (strlen(session_id()) < 1) {
    session_start();
}

Addition: For all php version

if ((function_exists('session_status') 
  && session_status() !== PHP_SESSION_ACTIVE) || !session_id()) {
  session_start();
}

Thank You!!