<?php

function smarty_modifier_strip($text, $replace = ' ')
{
    return preg_replace('!\s+!', $replace, $text);
}

function to_hex($str) {
    $hex_str = '';
    for ($i=0; $i < strlen($str); ++$i) {
        $char = substr($str, $i, 1);
        $hex_str .= dechex(ord($char));
    }

    return $hex_str;
}


$a = '格';

$b = smarty_modifier_strip($a);

var_dump(to_hex($a));
var_dump(to_hex($b));

?>

string(6) "e6a0bc"
string(6) "e6a0bc"