php错误接管

<?php
set_error_handler("error_function",E_ALL);
try{
    echo 'ok';
    echo $_POST['id'];
}catch(Exception $e){
    echo $e->getMessage();
}

function error_function($errno, $errstr, $errfile, $errline) {
    echo "<b>Custom error:</b> [$errno] $errstr<br>";
    echo " Error on line $errline in $errfile<br>";
}