I would like to know how to send a post request in curl and get the response page.
You need to set the request to post using CURLOPT_POST and if you want to pass data with it, use CURLOPT_POSTFIELDS:
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "http://www.example.com/");
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
$data = array(
'username' => 'foo',
'password' => 'bar'
);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
$contents = curl_exec($ch);
curl_close($ch);