Autoscroll in bash script output called from PHP

Question

I have a PHP script which prints the output of a bash script (actually it is an expect script), which looks like this:

<?php

ob_implicit_flush(true);
ob_end_flush();

$cmd = "./expect_script.sh";

$descriptorspec = array(
   0 => array("pipe", "r"),
   1 => array("pipe", "w"),
   2 => array("pipe", "w") 
);

$process = proc_open($cmd, $descriptorspec, $pipes, realpath('./'), array());

echo '<pre>';
if (is_resource($process)) {
    while ($s = fgets($pipes[1])) {
        print $s;

    }
}
echo '</pre>';
?>

So I wanted to get the real time output with automatic scroll at the end of the page with every new line appearance and I found this: printing process output in realtime

Then I added the proposed html code to my script as follows:

<html><head>
<script language="javascript">
var int = self.setInterval("window.scrollBy(0,1000);", 200);
</script>
</head>
<body>

<?php

ob_implicit_flush(true);
ob_end_flush();

$cmd = "./expect_script.sh";

$descriptorspec = array(
   0 => array("pipe", "r"),
   1 => array("pipe", "w"),
   2 => array("pipe", "w") 
);

$process = proc_open($cmd, $descriptorspec, $pipes, realpath('./'), array());

echo '<pre>';
if (is_resource($process)) {
    while ($s = fgets($pipes[1])) {
        print $s;

    }
}
echo '</pre>';
?>

</body>
</html>

However, when script finishes the web browser won't let me browse to the top of the page because it is still scrolling to the bottom.

How shall avoid it so that I can browse once the script is finished?

score 1 · Accepted Answer · answered Apr 07 '17 at 09:00

you are using setInterval to repeat some task and never ask it to stop that.

you will need to stop setInterval from repeating itself , at the end of your php code add :

echo '</pre>';
echo '<script language="javascript">self.clearInterval(int);</script>';

also you will need to close your proc process :

if (is_resource($process)) {
    while ($s = fgets($pipes[1])) {
        print $s;

    }
    proc_close($process);
}

Autoscroll in bash script output called from PHP

1 Answers1