PHP Session Warning question

[[email protected]]

I'm just starting to use PHP Sessions.  I have a simple test case to see how Sessions behave which was derived using an example from a reference text.  I have two scripts (Code samples below), TESTD.php and TESTE.php, each of which has a link pointing to the other.  I use start sessionstart () in each of them.  Using the links, I can toggle back and forth and the Session ID remains the same and a test variable which counts the toggles keeps the correct count as I toggle back and forth.  PROBLEM: When script TESTE.php runs, I gets a Warning Signal (Sample below) that I don't understand.  HELP NEEDED: I need to understand what I'm doing wrong that is causing the warning signal and how to eliminate it. 

 

Samples are attached as follows....

In attached file PHPFreakshelp-02.txt

  1. TESTD.php CODE

  2. TESTE.php CODE

  3. TESTD display

  4. TESTE display which includes the Warning

The Warning is as follows...

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers

already sent (output started at /home/unitcons/public_html/unitresearch02/TESTE.php:2) in

/home/unitcons/public_html/unitresearch02/TESTE.php on line 9

 

All help is greatly appreciated.

Bob G.

 

[attachment deleted by admin]

[[email protected]]

Sorry...there are two typo's in the code examples that I included in the attachment PHPFreakshelp-02.txt that I attached to my post.  They are missing brackets needed to close a function. 

The file attached to this reply, PHPFreakshelp-02b.txt corrects the error.

 

Bob G.

 

[attachment deleted by admin]

[laffin]

U forgot to mention you do have error reporting on, and php probably sent error messages when you called your function, as undefined variables.

which is a simple fix, just define the variables before sending it to your function

$sessionid=$FBemail=$FBVisitCount=null;

sessionstart ($sessionid, $FBemail, $FBVisitCount) ;



function sessionstart ($sessionid, $FBemail, $FBVisitCount)

 

when using sessions, you cant send any display code (this includes error reporting)

so its good practice not to use functions to start a session

but use session_start immediately in the script.

 

<?php
session_start();

 

this way, you can avoid the error reporting sending display code

 

[[email protected]]

laffin,

  Thanks for trying but your diagnosis is incorrect.  None of your recommendations corrected the problem. 

  1. Re. Warning: The line it references is "session_start () ;" and it states "Cannot send session cache limiter - headers already sent" so it is related to a session variable, not generic variables.    I don't know how to deal with the headers mentioned.

2. Re. error reporting:  I did not realize that I could turn off error reporting but I actually don't want to turn it off.

 

So, I still need help.    Php Freaks....Please chime in.

Cheers,

Bob G.

[laffin]

if you have the above, than you should also check before the <?php opening tag, its common to see this error because of a newline or space before the <?php tag.

 

there should be nothing in front of <?php tag, it should be the very first line, otherwise your sending out display code.

[teamatomic]

<?php

 

sessionstart ($sessionid, $FBemail, $FBVisitCount) ;

 

function sessionstart ($sessionid, $FBemail, $FBVisitCount)

{

global $sessionid, $FBemail, $FBVisitCount  ;

 

session_start();<<<<<<< Move this to right under the php start tag

 

 

HTH

Teamatomic

[[email protected]]

teamatomic, laffin...

  Thanks again for trying but I tested all of your suggestions previously and they did not change the behavior.  However, I did find a change that eliminated the problem.  I don't know why the problem was eliminated by this.  Maybe you can explain.  Here's the story...

  I got into this fix when I found example code for counting the times a session is invoked.  That code is in my prior samples but repeated below in part.  I thought the Warning might have something to do with a session variable and the only one I had, other than sessionid(), was $_SESSION['count'].  Experience told me to change something so I changed the term 'count' to 'visitcount' in all instances and the Warnings stopped and the code worked as I expected it should in the first place.  Note that the code was the same in TESTD as it was in TESTE but TESTD never generated the Warning.  I changed the term 'count' in both of the files but I may not have needed to do that in TESTD.

 

CODE EXCERPT

....if (empty($_SESSION['count']))

{

  $_SESSION['count']=1 ;

}

  else

{

  $_SESSION['count']++;

)

.....

 

NOTE: I'll leave this item open for a bit to see if anyone can explain why my change elimianted the problem.

 

Cheers,

Bob G