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.