Multibyte friendly tab to space replacer

tab2space.php

<?php

/**
 * Multibyte friendly tab replacer.
 * @param string $line Line with tabs to convert
 * @param int $tabsize Number of space characters in full width tab
 * @return string Line without tabs
 */
function tab2space($line, $tabsize = 4)
{
    while (($t = mb_strpos($line, "\t")) !== false) {
        $preTab = $t ? mb_substr($line, 0, $t) : '';
        $line = $preTab . str_repeat(' ', $tabsize - (mb_strlen($preTab) % $tabsize)) . mb_substr($line, $t + 1);
    }
    return $line;
}