"The following error types cannot be handled with a user defined function: E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR, E_COMPILE_WARNING, and most of E_STRICT raised in the file where set_error_handler() is called."
This is not exactly true. set_error_handler() can't handle them, but ob_start() can handle at least E_ERROR.
<?php
function error_handler($output)
{
$error = error_get_last();
$output = "";
foreach ($error as $info => $string)
$output .= "{$info}: {$string}\n";
return $output;
}
ob_start('error_handler');
will_this_undefined_function_raise_an_error();
?>
