Run process with realtime output in PHP

Question

I am trying to run a process on a web page that will return its output in realtime. For example if I run 'ping' process it should update my page every time it returns a new line (right now, when I use exec(command, output) I am forced to use -c option and wait until process finishes to see the output on my web page). Is it possible to do this in php?

I am also wondering what is a correct way to kill this kind of process when someone is leaving the page. In case of 'ping' process I am still able to see the process running in the system monitor (what makes sense).

Answer 1

This worked for me:

$cmd = "ping 127.0.0.1";

$descriptorspec = array(
   0 => array("pipe", "r"),   // stdin is a pipe that the child will read from
   1 => array("pipe", "w"),   // stdout is a pipe that the child will write to
   2 => array("pipe", "w")    // stderr is a pipe that the child will write to
);
flush();
$process = proc_open($cmd, $descriptorspec, $pipes, realpath('./'), array());
echo "<pre>";
if (is_resource($process)) {
    while ($s = fgets($pipes[1])) {
        print $s;
        flush();
    }
}
echo "</pre>";