End php socket connection in javascript

Question

I have a PHP script which opens a socket connection to a machine on the same network and waits for a response for up to 60 seconds then returns the result. This script is called upon using an ajax request on the "main" page which displays a message containing the result.

Problem is I want to be able to end the socket connection from the "main" page at any time, is this something that can be done? Or can anyone else think of a better way of doing this?

Thanks!

it's hacky, but you can send a second ajax call that fires a shell command to find and kill the process with the socket connection...assuming you can identify the correct process in the process list — billrichards, Jul 16 '20 at 23:09
You can't close the socket from the Client side. You will need a PHP Script that can be aware of the File Pointer and can then close the socket. This can then be called via AJAX from the Client. I can't recall if you can store a FP in a Session variable. Might be easier to get the Process ID of the Socket and then kill then via another script. — Twisty, Jul 16 '20 at 23:11
It would be best to edit your post and include a sample of your code. — Twisty, Jul 16 '20 at 23:15

score 1 · Accepted Answer · answered Jul 16 '20 at 23:32

Here is a really lite weight and untested theory.

open.php

<?php
session_start();
$_SESSION['fp'] = fsockopen($_GET['url'], 80, $errno, $errstr, 60);
// Do listen for 60 seconds, get data
while (!feof($_SESSION['fp'])) {
  echo fgets($_SESSION['fp'], 128);
}
fclose($_SESSION['fp']);
unset($_SESSION['fp']);
?>

close.php

<?php
session_start();
if(isset($_SESSION['fp'])){
  fclose($_SESSION['fp']);
  unset($_SESSION['fp']);
}
?>

JavaScript

$(function(){
  $("#go").click(function(){
    $.get("open.php", { url: $("#url").val() }, function(results){
      console.log(results);
    });
  });
  $("#stop").click(function(){
    $.get("close.php");
  });
});

The idea here is that the File Pointer is stored in a session variable, so it can be called upon by other scripts. Since you didn't provide an example, I cannot say if this will work for you. I have never tested it since I've never wanted a script to close the connection prematurely. I've wanted to remain open until I got all my data and then close at EOF.

Alternatively, you can do something similar with the Process ID. Each PHP Script gets a PID when running. Discussed more here: How to kill a linux process using pid from php?

While I didn't use the exact answer above it did lead me to a great idea that I just didnt consider before. I set a session variable to be true at the start of the page, and then made a button on the page which when clicked would load a php page to set that session variable to false. The script handling the socket connection would close the connection then on its end whenever a response was received OR when the session variable was false. Such a simple idea - thanks for the tip! — Pharm, Jul 18 '20 at 00:46

End php socket connection in javascript

1 Answers1