Session Error - Cannot send session cache limiter

jamessmb

Ok, trying to understand this is getting pretty tedious. In ColdFusion it's VERY easy to set a session variable. What am I doing wrong?

Code:
<?php
session_start();
?>

// query a database works correctly
// try to set a session var to a value from the recordset

$_SESSION['sv_userID'] = $row_Recordset1['subid'];

I get the following error in the browser:

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at c:\inetpub\wwwroot\test\MemberLogin.php:8) in c:\inetpub\wwwroot\test\MemberLogin.php on line 12

I have all 6 of my PHP books open and am still can't get it figured out.

WinXP, PHP Version 4.3.2, IIS 5.1
session
Session Support enabled

Registered save handlers files user

Directive Local Value Master Value
session.auto_start Off Off
session.bug_compat_42 On On
session.bug_compat_warn On On
session.cache_expire 180 180
session.cache_limiter nocache nocache
session.cookie_domain no value no value
session.cookie_lifetime 0 0
session.cookie_path / /
session.cookie_secure Off Off
session.entropy_file no value no value
session.entropy_length 0 0
session.gc_divisor 100 100
session.gc_maxlifetime 1440 1440
session.gc_probability 1 1
session.name PHPSESSID PHPSESSID
session.referer_check no value no value
session.save_handler files files
session.save_path C:\PHP\sessiondata C:\PHP\sessiondata
session.serialize_handler php php
session.use_cookies On On
session.use_only_cookies Off Off
session.use_trans_sid Off Off

Any help in figuring this out would be greatly appreciated. It just shouldn't be this difficult.

Thanks,
James

dalecosp

It isn't difficult. But, you can not send any output to the browser under any circumstances prior to session_start(). Look for extraneous white space ... probably around line 8 ... or are you outputting HTML or etc., there?

jamessmb

That was it. I had session_start() after the </head> tag.

Thanks,
James

dalecosp

Yup --- it's a good idea to do as much logic as possible before doing any output on most scripts....

You're welcome!

jamessmb

Ok, now why isn't this working?

I'm setting the session var to the field in a recordset, then going to another page. On that page, I want the session var to echo. I get the following error:

Notice: Undefined variable: _SESSION in c:\inetpub\wwwroot\campuscorkboard\MemberAccountDetails.php on line 13

Login page code:
if($totalRows_Recordset1 >= 1){
$SESSION['svUserID'] = $row_Recordset1['subid'];
$SESSION['svFirstName'] = $row_Recordset1['fName'];
header("Location: " . "MemberAccountDetails.php");

MemberAccountDetails.php code:
<td colspan="3">Welcome <?php echo $_SESSION['svFirstName']; ?></td>

However if I do this in the Login page:
if($totalRows_Recordset1 >= 1){
$SESSION['svUserID'] = $row_Recordset1['subid'];
$SESSION['svFirstName'] = $row_Recordset1['fName'];
echo $_SESSION['svFirstName'];

I get the session var to echo.

What's wrong with my code?

Thanks,
James

dalecosp

Hmm, that's a bit trickier. One of the first things I'd ask is "which line is line 13?"

But, since we're getting an "undefined" error ... first, make sure you're calling session_start() on every page on which a $_SESSION var is to be used (prior to calling the var, of course...)

And then there would be the question of whether the session is following you, as you say that it's OK on the first page, but not the 2nd (or am I misunderstanding?) Is the session ID is being passed via the URL? If not, it's trying to use a cookie, and your browser settings may be preventing it from doing so ... just a guess; but I've seen that twice already here in the last 24 hours ...

jamessmb

Ok, I understand now.

Every page that uses a session var I need to preface the code with session_start();

Line 13 was that line of code trying to echo the session var.

Thanks for your help. I appreciate it and am on my way.

James

dalecosp

Originally posted by jamessmb
Ok, I understand now.

Yes, you do!! 🙂

There is also a session_auto_start feature that can be turned on in php.ini, but there's no good reason unless every page is gonna have session vars...