Question

How to right php regex to extract hidden fiedls name , value pair from html ?

Answer 1

As per usual, DO NOT USE REGEX TO PROCESS HTML

Use dom:

$dom = new DOMDocument;
$dom->loadHTML('your html here');

$xp = new DOMXPath($dom);
$hidden = $xp->query("//input[@type='hidden']");
for ($i = 0; $i < $hidden->length; $i++) {
    echo $hidden[$i]->getAttribute('name');
}

EDIT: Just saw your comment about the malformed html: Use HTMLPurifier to clean up the HTML. Hopefully it’s not so mangled that Purifier can’t clean it up to a state that DOM will accept it.