Example 1. restore_error_handler() example
     Decide if unserialize() caused an error, then
     restore the original error handler.
    
<?php function unserialize_handler($errno, $errstr) {     echo "Invalid serialized value.\n"; }
  $serialized = 'foo'; set_error_handler('unserialize_handler'); $original = unserialize($serialized); restore_error_handler(); ?>
 | 
The above example will output:
Invalid serialized value.  |