check login, but within a function? can't modify header info

heather_acrop

Hi,

I'm trying to check if a user is logged in from within each page... I want to just call a function, so that I don't have duplicate code on every page.... So I tried this:

On each page:

session_start();
check_login();

On included scripts page:

function check_login(){

// if not logged in, redirect to login page
if(!$_SESSION["logged_in"]){
header("Location: login.php");
exit;
}

}

...But, I get an error message saying "Cannot modify header information - header already created" or something like that... So, I was wondering, is there any other way to do the whole redirecting thing without using header? Or, just any other way that it can be possible that I can have it in a function. I guess my question is, what is the norm?

Thanks,

Heather

devinemke

read up on headers

heather_acrop

i already have read up on headers... i know that a header has to be before anything else on the page. that is why i am asking how it would be possible to redirect from a function. in order to use that function i have to include the script that uses that function, and i have to include it before i call the function, making the header be after the include.

devinemke

if you read the info from the link i provided you would see that no output can be sent to the browser proir to calling the [man]header[/man] (including whitespace). you can have all the server-side code you want before calling [man]header[/man] (includes, functions, etc...) but again, no output to the client. the reason you are getting the "Cannot modify header information..." error is because you have output going to the browser before calling [man]header[/man]. you can always control how/when output is sent to the browser via the Output Control Functions.