Can an http post request sent by the client socket trigger the isset of the PHP page on the server? Solution

Can an http post request sent by the client socket trigger the isset of the PHP page on the server? I use a SOCKET on the client to send an HTTP POST request POST/send. PHP/1.1 Host: www. temp. comUser-Agent: Mozilla/5.0 (can an http POST request sent by a client socket trigger the isset of the PHP page on the server?
I use a SOCKET on the client to send an HTTP POST request.

POST/send. php HTTP/1.1
Host: www.temp.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv: 1.7.6)
Gecko/20050225 Firefox/1.0.1
Content-Type: application/x-www-form-urlencoded
Content-Length: 6
Connection: Keep-Alive

Testname =


The page for www.temp.com/send.php is as follows:



If (isset ($ _ POST ['submit ']) {
If ($ _ POST ['testname'] = 'a '){
// Judgment and processing
}
}
?>

My question is: after the client sends an HTTP request header, will the php page execute isset ($ _ POST ['submit ']) and determine the content of testname?

------ Solution --------------------
No!
Because you have not sent the submit variable
------ Solution --------------------

PHP code

  Look at log.txt.