$text = 'cod html';

preg_match_all('/<input\b(?:[^>]*\btype="text"[^>]*\bname="([^"]+)"[^>]*|[^>]*\bname="([^"]+)"[^>]*\btype="text"[^>]*)>/i', $text, $matches);
$subregex = array(1, 2);
$names = array();
foreach($subregex as $regex)
{
    foreach($matches[$regex] as $match)
    {
        if (trim($match))
        {
            $names[] = trim($match);
        }
    }
}

print_r($names);