PJ wrote:
> Shawn McKenzie wrote:
>> PJ wrote:
>>> This really needs some explanation
>>> I found this on the web:
>>> <?php echo `whoami`; ?>
>>> with it there was the comment "the direction of those single-quotes matters"
>>> (WHY ?)
>>> and it works....
>>> But this (_*FROM THE PHP MANUAL***_ * -  exec()* executes the given
>>> /command/ ) does not,
>>> |<?php
>>> // outputs the username that owns the running php/httpd process
>>> // (on a system with the "whoami" executable in the path)
>>> echo exec('whoami');
>>> ?> |
>>> What is going on here?
>>> And I often find such discrepancies in examples - and some wonder why I
>>> seem to be so stupid... and don't know the fundamentals... :-\
>> Others have shown how exec() returns the output.  If you use
>> shell_exec() it's the same as using the backticks:
>> <?php echo `whoami`; ?>
>> -or-
>> <?php echo shell_exec("whoami"); ?>
>> You can use single quotes here also, i used double so you can easily
>> tell they are not backticks
> What is not clear to me is why would I need to use a shell? What kind of
> situations call for it's use?

Well, if you need to run any executable on the server to have it do
something or return something.  Whether you need to get some information
from the system or run an executable that does something specific.
Maybe you want to do a 'ps -ef' to get processes on linux, or maybe you
want to start a service on windows 'netstart SOMESERVICE'.


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