What is the purpose of using session.use_trans_sid in PHP and how does it affect the visibility of the SID in the URL?

The purpose of using session.use_trans_sid in PHP is to enable transparent session ID passing in URLs for sessions that do not support cookies. This setting allows PHP to automatically append the session ID to URLs when cookies are not available. However, this can potentially expose the session ID in the URL, making it visible to users and increasing the risk of session hijacking.

// Enable transparent session ID passing in URLs
ini_set('session.use_trans_sid', 1);