Headers already sent error in conditional block

[mercedes1954]

Hi,

I am using header("Locatio n: in two places in my script, but they are
in mutually exclusive blocks i.e if one runs, the other can't.

However, an error is thrown pointing to the session_destroy () line
saying it started output. But it's not being called!

I removed the header() line below session_destroy () but it still gives
the same error so it seems to be session_destroy () existing in the
script even if not called.
if($loginmode== "logout")
{
$_SESSION=array ();
if(isset($_COOK IE[session_name()]))
{
setcookie(sessi on_name(),'',ti me() -42000,'/');
}

session_destroy ();

header("Locatio n: index.php");
exit;
}
// Another bhlock that can't run if the first block has......

if($errorMessag e=="")
{
// Set the $_SESSION variables for this logon

$_SESSION['loginuser']=$row['username'];
$_SESSION['loginlevel']=$row['level'];

header("Locatio n: index.php");
exit;
}
How can I write the php script so that multiple header("Locatio n:
options are present, or can co-exist with session_destroy () ?

[Captain Paralytic]

On 9 Jun, 13:35, mercedes1954 <alandam...@hot mail.comwrote:

Hi,

I am using header("Locatio n: in two places in my script, but they are
in mutually exclusive blocks i.e if one runs, the other can't.

However, an error is thrown pointing to the session_destroy () line
saying it started output. But it's not being called!

I removed the header() line below session_destroy () but it still gives
the same error so it seems to be session_destroy () existing in the
script even if not called.

if($loginmode== "logout")
* * * * {
* * * * $_SESSION=array ();
* * * * if(isset($_COOK IE[session_name()]))
* * * * * * * * {
* * * * * * * * setcookie(sessi on_name(),'',ti me() -42000,'/');
* * * * * * * * }

* * * * session_destroy ();

* * * * header("Locatio n: index.php");
* * * * exit;
* * * * }

// Another bhlock that can't run if the first block has......

if($errorMessag e=="")
* * * * {
* * * * // Set the $_SESSION variables for this logon

* * * * $_SESSION['loginuser']=$row['username'];
* * * * $_SESSION['loginlevel']=$row['level'];

* * * * header("Locatio n: index.php");
* * * * exit;
* * * * }

How can I write the php script so that multiple header("Locatio n:
options are present, or can co-exist with session_destroy () ?

Not that I doubt you or anything, but what precisely stops the second
block from running if the first one has run? Why can't there be
something in $errorMessage just because $loginmode=="lo gout"?

Also, the complete error message will detail 2 lines, the one where
output was started and the one that is trying to send more headers. Is
the second reference to the header() line directly below the
session_destroy ()?

Also, looking at your code in the first block, you seem to check for
the presence of a session by checking for $_COOKIE[session_name()].
However, even if you do not find this cookie, you still invoke
session_destroy (). I would expect thhis to give an error along the
lines of "Trying to destroy uninitialized session..." and this would
certainly be some "output already sent".

[mercedes1954]

On Jun 9, 2:16*pm, Captain Paralytic <paul_laut...@y ahoo.comwrote:

On 9 Jun, 13:35, mercedes1954 <alandam...@hot mail.comwrote:

Hi,

I am using header("Locatio n: in two places in my script, but they are
in mutually exclusive blocks i.e if one runs, the other can't.

However, an error is thrown pointing to the session_destroy () line
saying it started output. But it's not being called!

I removed the header() line below session_destroy () but it still gives
the same error so it seems to be session_destroy () existing in the
script even if not called.

if($loginmode== "logout")
* * * * {
* * * * $_SESSION=array ();
* * * * if(isset($_COOK IE[session_name()]))
* * * * * * * * {
* * * * * * * * setcookie(sessi on_name(),'',ti me() -42000,'/');
* * * * * * * * }

* * * * session_destroy ();

* * * * header("Locatio n: index.php");
* * * * exit;
* * * * }

// Another bhlock that can't run if the first block has......

if($errorMessag e=="")
* * * * {
* * * * // Set the $_SESSION variables for this logon

* * * * $_SESSION['loginuser']=$row['username'];
* * * * $_SESSION['loginlevel']=$row['level'];

* * * * header("Locatio n: index.php");
* * * * exit;
* * * * }

How can I write the php script so that multiple header("Locatio n:
options are present, or can co-exist with session_destroy () ?

Not that I doubt you or anything, but what precisely stops the second
block from running if the first one has run? Why can't there be
something in $errorMessage just because $loginmode=="lo gout"?

Also, the complete error message will detail 2 lines, the one where
output was started and the one that is trying to send more headers. Is
the second reference to the header() line directly below the
session_destroy ()?

Also, looking at your code in the first block, you seem to check for
the presence of a session by checking for $_COOKIE[session_name()].
However, even if you do not find this cookie, you still invoke
session_destroy (). I would expect thhis to give an error along the
lines of "Trying to destroy uninitialized session..." and this would
certainly be some "output already sent".- Hide quoted text -

- Show quoted text -

Thank you for the quick response. My brain tricked me into looking at
line 19 - where session_destroy () is - instead of realising it was
line 19 of a small include file that had 2 blank lines after the ?>

Now how many times did I read that in countless posts before turning
here for help???

Thanks for the other comments, but it was a vastly cut down piece of
code and the original addressed your concerns.

Thanks again for your time.