wtf.php

$str     = "あAいうえおaかAきくけこaさAしすせそ";
$pattern = "a";
mb_ereg_search_init($str, $pattern, "i");
while (mb_ereg_search()) {
	print_r( [mb_ereg_search_getpos(), mb_ereg_search_getregs()] );
}

options for mb_ereg_* are all defined in
http://us3.php.net/manual/en/function.mb-regex-set-options.php.

not sure why the syntax is super different from other regex functions…