php header and shell_exec
<p>I have a couple of questions about a php script I'm looking at,</p>

<p>it has a bunch of code that I'm trying to figure out what it does:</p>

<p>the main portions are:</p>

<pre><code>echo shell_exec("bash '".$shell_script_to_execute."' '".$jobtype."' '".
$REMOTE_USER."' '".$clientname."' '".$jobcommand."' '".$jobid."' '".
$servername."'  '".$rootaccess."'  ");

header("Location: https://192.168.42.78/operator/{$php_script_to_execute}?time=$time&amp;jobname=$jobname&amp;clientname=$clientname&amp;groupname=$groupname");
</code></pre>

<p>What exactly does shell_exec function do?  and the header function?  Is header just a redirect?  What if  I have echo statements before that, will it redirect to the header page first and then display the echos?</p>

<p>Thanks</p>
