Boyer-Moore-Horspool string matching algorithm

Boyer-Moore-Horspool.php

<?php
define('UCHAR_MAX',255);
function boyermoore_horspool_memmem($haystack,$needle){
    $hlen = strlen($haystack);
    $nlen = strlen($needle);
    $scan = 0;
    $bad_char_skip[UCHAR_MAX + 1];
    if ($nlen <= 0 || !$haystack || !$needle) { return NULL; }
    for ($scan = 0; $scan <= UCHAR_MAX; $scan = $scan + 1)
        $bad_char_skip[$scan] = $nlen;
    $last = $nlen - 1;
    for ($scan = 0; $scan < $last; $scan = $scan + 1)
        $bad_char_skip[$needle[$scan]] = $last - $scan;
    while ($hlen >= $nlen){
        for ($scan = $last; $haystack[$scan] == $needle[$scan]; $scan = $scan - 1)
            if ($scan == 0) { return $haystack; }
        $hlen -= $bad_char_skip[$haystack[$last]];
        $haystack += $bad_char_skip[$haystack[$last]];
    }
    return NULL;
}
?>

This is my code from code4expert.com you could at least not copy other peoples code dude.