PHP：在Web浏览器中输出system / Shell_exec命令输出

Question

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.

Answer 1

Use output buffering and flush. You might also want to look into the Symfony 2 process component.