I tried to output a simple ping command on a web page in a similar way( and same time) as it is displaying in terminal, using shell_exec; But it is displaying only after the complete execution, while I needed it to display whenever it is displaying on terminal,
My code is
<?php
$i= shell_exec("ping -c 4 google.com");
echo "<pre> $i <pre>";
?>
It is waiting for a while and the dumping the whole thing on a single shot.. can PHP recognize the outputting of each line and display it on the web page
EDIT
I tried this also
<?php
$proc = popen("ping -c 4 google.com", 'r');
echo '<pre>';
while (!feof($proc)) {
echo fread($proc, 4096);
}
echo '</pre>';
?>
But still I gets the same result..
EDIT
When I tried to execute this PHP code in terminal , ( php test.php) it is working properly in the same way it gives when we directly do ping on server. but in web page it is still the same.
Use output buffering and flush. You might also want to look into the Symfony 2 process component.
if can resolve using apache execution user. if your root user is diffrent and server user different then it will not allow to execute command line command.
Uhm, strange behavior from the web browser. I'm using this code:
<?php
ob_end_flush();
ini_set("output_buffering", "0");
ob_implicit_flush(true);
function pingtest()
{
$proc = popen("ping -c 5 google.com", 'r');
while (!feof($proc))
{
echo "[".date("i:s")."] ".fread($proc, 4096);
}
}
?>
<!DOCTYPE html>
<html>
<body>
<pre>
Immediate output:
<?php
pingtest();
?>
</pre>
</body>
</html>
In the browser the content appears after all bytes has been received. But, the content is actually delivered on time, do this test:
wget -O - -q "http://localhost/ping.php"
You will see that the response is delivered by php & apache2 on time.
I'm using this kind of execution on long task for a while, but using a more complex solution:
interface (test.html)
<!DOCTYPE html>
<html>
<head>
<title>Simple EventSource example</title>
</head>
<body>
<script type="text/javascript">
function eventsourcetest() {
var ta = document.getElementById('output');
var source = new EventSource('test.php');
source.addEventListener('message', function(e) {
if (e.data !== '') {
ta.value += e.data + '
';
}
}, false);
source.addEventListener('error', function(e) {
source.close();
}, false);
}
</script>
<p>Output:<br/><textarea id="output" style="width: 80%; height: 25em;"></textarea></p>
<p><button type="button" onclick="eventsourcetest();">ping google.com</button>
</html>
Server Side Component (test.php)
<?php
ob_end_flush();
ini_set("output_buffering", "0");
ob_implicit_flush(true);
header('Content-Type: text/event-stream');
header('Cache-Control: no-cache');
function echoEvent($datatext) {
echo "data: ".implode("
data: ", explode("
", $datatext))."
";
}
echoEvent("Start!");
$proc = popen("ping -c 5 google.com", 'r');
while (!feof($proc)) {
echoEvent(fread($proc, 4096));
}
echoEvent("Finish!");
Put both files in one place on a webserver and enter test.html, I think this is what you are looking for from the beginning.
Its not a PHP matter, or rather its a shared matter between php and the browser.
In PHP: Make sure output buffering is off, you can do this by running ob_end_clean() before outputting anything.
As this SO post suggests you have to either pad the very first string outputted to 512 bytes OR specify a charset encoding via http header. The padding solution may very well be the easiest way around this, its basically this: echo(str_pad("Live Ping Test!",512)); and then start echoing the result of your fread.
You might want to try using flush() to flush the output as and when its ready, and use passthru() to execute the command.
Carlos C Soto is right, you have to use javascript. EventSource is the way to go. Basically, it's javascript code that will constantly call a url
You can write the output of ping in a file, and write a php script that will read the last line, then call this script with eventsource.
Search "Server Sent Events" on the web to find more examples
I tested Carlos's answer on my side...
and I HAD to add flush();ob_flush(); for it to work properly (both needed flush AND ob_flush)
like this
<?php
$proc = popen("ping -c 5 google.com", 'r');
while (!feof($proc))
{
echo "[".date("i:s")."] ".fread($proc, 4096).'<br>';flush();ob_flush();
}
?>