Throw error when post_max_size was reached

maxpostsize.php

<?php

    function checkPostSizeExceeded() {
        $maxPostSize = iniGetBytes('post_max_size');
    
        if ($_SERVER['CONTENT_LENGTH'] > $maxPostSize) {
            throw new Exception(
                sprintf('Max post size exceeded! Got %s bytes, but limit is %s bytes.',
                    $_SERVER['CONTENT_LENGTH'],
                    $maxPostSize
                )
            );
        } else if ($_SERVER['HTTP_TRANSFER_ENCODING'] == 'chunked') {
            $fh   = @fopen('php://input', 'r');
            if ($fh)
            {
                $postsize = 0;
                while (!feof($fh))
                {
                    $s = fread($fh, 8096);
                    if ($s !== false)
                    {
                        $postsize += strlen($s);
                        
                        if ($postsize > $maxPostSize) {
                            throw new Exception(
                                sprintf('Max post size exceeded! Limit is %s bytes.',
                                    $maxPostSize
                                )
                            );
                        }
                    }
                }
                fclose($fh);
            }
        }
    }
    
    function iniGetBytes($val)
    {
        $val = trim(ini_get($val));
        if ($val != '') {
            $last = strtolower(
                $val{strlen($val) - 1}
            );
        } else {
            $last = '';
        }
        switch ($last) {
            // The 'G' modifier is available since PHP 5.1.0
        	case 'g':
        	    $val *= 1024;
        	case 'm':
        	    $val *= 1024;
        	case 'k':
        	    $val *= 1024;
        }
    
        return $val;
    }