function retrieveCurrentUserInfoFromFile($filename) { $userData = file_get_contents($filename); $userArray = explode("\n", $userData); $currentUser = array(); foreach($userArray as $user) { $userDetails = explode(",", $user); if($userDetails[0] == $_SESSION['username']) { //assuming username is stored in session $currentUser = array( "username" => $userDetails[0], "fullname" => $userDetails[1], "email" => $userDetails[2] ); } } return $currentUser; }In this example, the function takes a filename as an argument and reads the contents of the file using the file_get_contents function. It then splits the file into an array of user details using the explode function. The function then iterates through the array to find the current user's details by comparing the username stored in the session variable with the username in the file. If a match is found, the user details are stored in an associative array and returned. This function does not seem to be part of any pre-existing package or library, but rather a custom function written for a specific application.