How do you "clear the screen" in PHP apps?

maktos

<?php
$userID=$_REQUEST['userID'];
if ($userID) {
print "Welcome back, " . $userID . ".";

sleep(2);

header("Location: http://www.chantcd.com/maktos/load_character.php");
exit;

}

(later on, there is a ?>

The above URL does exist - but all that happens, is I see the "welcome back" message. I tried everything, and there doesn't seem to be a setting in PHP.ini that affects this.

I am using Redhat Linux 9.0 and PHP 4.2.2 that came with it.
I am running Apache 2.0 also.

ScubaKing22

That's because you're not allowed to use headers after something has been output onto the page. Try having a look at ob-start(), which will allow you to use the print statement followed by a header() statement.

Hope this helps 😉

maktos

Using headers (or some other function)
How do you say "Ok, this page is done with - let's bring up a new page"

Something like the programmer's old friend, "clearscreen(), clrscr() etc."

It seems critical for any application, to be able to clear the screen and draw new contents.

But as you are executing PHP code, obviously things get written - does that mean you have to never send another header for the life of the code?

I doubt it of course - but what simple thing am I missing?

Matthew

tekky

you can use META refresh...to delay a redirect... but there is no PHP function that does this for you.... other than header() which cant be used after output unless using ob-start

Weedpacket

Originally posted by maktos
I doubt it of course - but what simple thing am I missing?

You're missing the basics of http. http is stateless: the client requests a resource from the server, the server sends back a response and that's the end of it. If you want the client to do something after that, it's up to the client to make a new request. Since PHP runs on the server, there are no facilities in PHP to make the client do anything. What it can do is send headers (before any content has been sent), or suitable code (typically Javascript) in the hopes that the client will run it - and if that code contains instructions to request a new page and the client runs it, then a new request will be sent to the server and a new page sent back in response.