Return numerical part of the HTML encoding of the Unicode character.

ordutf8.php

<?php

/**
 * Return numerical part of the HTML encoding of the Unicode character.
 *
 * @param string $char
 * @return int
 */
function ordutf8(string $char) : int
{
    $code = ord(substr($char, 0, 1));

    if ($code > 127) {

        //110xxxxx
        $bytes = 2;
        $count = 0;

        if ($code > 223) {
            //1110xxxx
            $bytes = 3;
            $count = 32;
        }

        if ($code > 239) {
            //11110xxx
            $bytes = 4;
            $count = 48;
        }

        $temp = $code - 192 - $count;

        for ($i = 1; $i < $bytes; $i++) {
            $code = $temp = $temp * 64 + ord(substr($char, $i, 1)) - 128;
        }
    }

    return $code;
}