$_SESSION variables not working - php

As a newcomer to PHP, I need to get $_SESSION variables working as part of a larger project. I am finding that the I cannot transfer data between .php files using $_SESSION variables. I Googled for similar problems and found this solved problem.Same problem
I reduced my code to the exact same as the solution to the problem, but it still exists. I have
sesstest.php
<?php
session_start();
$_SESSION['test']="TEST SESSION TEXT";
header('location:sessreceive.php');
?>
sessreceive.php
<?php session_start();
echo $_SESSION['test'];
?>
I have cookies enabled and it is the same in Firefox and IE. The site I'm accessing is a Raspberry Pi on my home network. It is running Apache2 under a Linux version. The session part of my php.ini is
Could anyone please suggest what might be wrong, as I get no output in sessreceive.php?

Make sure that the session.save_path exists. Sometimes that is the problem.

Can try var_dump($_SESSION);, to see what exactly it contains.
Also, try echo session_id(); in both cases to ensure you're picking up the same session in both cases.
Make sure Apache can write to the session.save_path (/var/lib/php5)

Related

PHP $_SESSION starts without session_start(), but not working through a session

I have a problem in my application using SESSION array. It has been working for a couple of weeks but then suddenly stopped working (without any noticable change in code or settings). I shortened the code to this:
<?php
session_start();
var_dump($_SESSION);
$_SESSION['meh'] = 'MEH';
?>
It shows an error: 'A session has alredy been started...'. This is now my whole code in index.php, which is the only file in server's directory. After the second (third...) run the $_SESSION is still empty. Working with PHP 7.0, testing on Firefox and Opera (Cookies allowed). On local server is everything fine. Any ideas how to fix it? Somewhere in config/cache or whatever? Thanks
you may have another session_start() in your code
or
try this
from the old answer
<?php
if(!isset($_SESSION))
{
session_start();
}
?>

Session PHP expire almost immediately

I've got a problem with my Session in PHP, if I refresh my page it set a new session_id each time.
I use the PHP built in server and PHP 7.1 and nothing more than that :
<?php
session_start();
echo session_id();
Each refresh give me a new Session Id. Each ? Not really in fact, if I refresh super quickly I have the same session id for 1 or 2 seconds.
I don't know where to look, my php.ini seems correct, my code too I believe.
My folder to register session is 777.
Where could I look or what test could I do ?
Edit : I don't know why but changing localhost to 127.0.0.1 in the built in server solved the issue
I don't know why but changing localhost to 127.0.0.1 in the built in server solved the issue.

Can't write PHP cookies or sessions on RackSpace server

I'm working on a RackSpace server, and I am unable to successfully write cookies or persistent sessions through PHP (I can write javascript cookies just fine).
The cookies are never written at all, and the sessions are never accessible on any page but the one they're written on. I've tried the exact same code on a different server, and it worked just fine -- so I'm assuming it's some kind of configuration issue.
Here's an example:
Sessions
Page 1:
session_start();
$_SESSION['mysession'] = 'hello';
//writes correct value
echo $_SESSION['mysession'];
Page 2:
session_start();
//this dumps 'NULL'
var_dump($_SESSION['mysession']);
Cookies:
//this never gets written.
setcookie($mycookie, $myvalue, time() + (86400 * 30), "/");
Are there any particular server settings I should be looking at?
I ran phpinfo, and see my session.save_path. I tried setting that to 777 just to see if it would help, but it did not.
I'm stumped, and their support couldn't help me. Anyone have any ideas?
Edit:
Upon closer inspection, I can see that the sessions are being written -- I just can't read them.
You can gather more information by creating a php file with content:
<?php phpinfo();
Request this site and search for the session settings.
- Are sessions really enabled?
- Which session save handler is used?
Maybe the session data is not even saved in a file and the error is anywhere else.

PHP resetting Session after some time

I know this problem has been presented here in SO and I've tried the solutions but it's still not fixed.
PHP is deleting the session after some time of inactivity (i assume 24 minutes as it's the default and seems to fit the testing).
I have the following code set in all the pages:
ini_set('display_errors', 0);
$sessionCookieExpireTime = 2880000;
session_set_cookie_params($sessionCookieExpireTime);
ini_set('session.gc_maxlifetime', $sessionCookieExpireTime);
session_start();
echo ini_get('session.gc_maxlifetime'); //echos 2880000 as expected
But the session still gets reset after 24 minutes (or so) of inactivity.
phpinfo() return the following output for session:
Any idea why this isn't working? (PHP 5.3.10)
Thanks
Although Marc B answer shares some great insight it wasn't working for me. I was pretty sure everything was fine with my script and I had nothing messing with the session in my code.
After an epic struggle I discovered that my problem was actually due to shared hosting environment. From the PHP doc:
“If different scripts … share the same place for storing the session
data then the script with the minimum value will [determine the
session timeout]“.
After this the problem was quite obvious. Some script (hosted on the same server) was using the default php.ini session.gc_maxlifetime and that was resetting my sessions.
The solution was to create a folder under the root of my hosting (make sure it's not web accessible), set the right permissions to it and then use session.save_path to tell php where to store my sessions. Something like:
ini_set("session.gc_maxlifetime","21600"); // 6 hours
ini_set("session.save_path", "/your_home/your_sessions/");
session_start();
This website provided great insight: php sessions on shared hosting
So if you come accross this issue make sure you follow Marc B recommendations and if that doesn't work try this out.
Best wishes!!
Are you doing this code in EVERY script that uses sessions? ini_set changes apply ONLY to the script they're executed in, and ONLY for the execution lifetime of that particular script.
If you want to make it a permanent global change, you'll have to modify php.ini, or put some php_values directives into http.conf/.htaccess.

session_start hangs

since a few hours our server hangs every time you do a session_start.
For testing purposes i created a script which looks like this:
<?php
session_start();
?>
Calling it from the console hangs and it can't even be stopped with ctrl-c, only kill -9 works. The same for calling it via Apache. /var/lib/php/session/ stays empty but permissions are absolutely fine, www can write and also has read permissions for all parent folders.
According to the admins there were no changes made on the server and there is no special code registered for sessions. The Server is CentOS 4 or 5 and yesterday everything was working perfectly. We rebooted the server and updated PHP, but nothing changed.
I've ran out of ideas, any suggestions?
UPDATE
We solved this problem by moving the project to another server, so while the problem still exists on one server there is no immediate need for a solution anymore.
I will keep the question open in case someone has an idea for others having a similar problem in the future, though.
There are many reasons for that, here are a few of them:
A. The session file could be opened exclusively.
When the file lock is not released properly for whatever reason, it is causing session_start() to hang infinitely on any future script executions.
Workaround: use session_set_save_handler() and make sure the write function uses fopen($file, 'w') instead of fopen($file, 'x')
B. Never use the following in your php.ini file (entropie file to "/dev/random"), this will cause your session_start() to hang:
<?php
ini_set("session.entropy_file", "/dev/random");
ini_set("session.entropy_length", "512");
?>
C.
session_start() needs a directory to write to.
You can get Apache plus PHP running in a normal user account. Apache will then of course have to listen to an other port than 80 (for instance, 8080).
Be sure to do the following things:
- create a temporary directory PREFIX/tmp
- put php.ini in PREFIX/lib
- edit php.ini and set session.save_path to the directory you just created
Otherwise, your scripts will seem to 'hang' on session_start().
If this helps:
In my scenario, session_start() was hanging at the same time I was using the XDebug debugger within PHPStorm, the IDE, on Windows. I found that there was a clear cause: Whenever I killed the debug session from within PHPStorm, the next time I tried to run a debug session, session_start() would hang.
The solution, if this is your scenario, is to make sure to restart Apache every time you kill an XDebug session within your IDE.
I had a weird issue with this myself.
I am using CentOS 5.5x64, PHP 5.2.10-1. A clean ANSI file in the root with nothing other than session_start() was hanging. The session was being written to disk and no errors were being thrown. It just hung.
I tried everything suggested by Thariama, and checked PHP compile settings etc.
My Fix:
yum reinstall php; /etc/init.d/httpd restart
Hope this helps someone.
To everyone complaining about the 30 seconds of downtime being unacceptable, this was an inexplicable issue on a brand new, clean OS install, NOT a running production machine. This solution should NOT be used in a production environment.
Ok I face the same problem on 2 PC, 1 is MAC mini XAMPP, 1 is Windows 10 Xampp.
Both is php spent infinity to run session_start(). Both PHP version is 7.x.x
I found that session files is lock to read and write. So that I added code to make PHP read session files and immediately unlock when done with
<?php
session_start([
'read_and_close' => true,
]);
?>
or
<?php
//For PHP 5.x
session_start();
session_write_close();
?>
After this PHP unlock session file => Problems solve
The problem: -
Iv experienced (and fixed) the problem where file based sessions hang the request, and database based sessions get out of sync by storing out of date session data (like storing each session save in the wrong order).
This is caused by any subsequent request that loads a session (simultaneous requests), like ajax, video embed where the video file is delivered via php script, dynamic resource file (like script or css) delivered via php script, etc.
In file based sessions file locking prevents session writing thus causing a deadlock between the simultaneous request threads.
In database based session the last request thread to complete becomes the most recent save, so for example a video delivery script will complete long after the page request and overwrite the since updated session with old session data.
The fix: -
If your ajax or resource delivery script doesnt need to use sessions then easiest to just remove session usage from it.
Otherwise you'd best make yourself a coffee and do the following: -
Write or employ a session handler (if not already doing so) as per http://www.php.net//manual/en/class.sessionhandler.php (many other examples available via google search).
In your session handler function write() prepend the code ...
// processes may declare their session as read only ...
if(!empty($_SESSION['no_session_write'])) {
unset($_SESSION['no_session_write']);
return true;
}
In your ajax or resource delivery php script add the code (after the session is started) ...
$_SESSION['no_session_write'] = true;
I realise this seems like a lot of stuffing around for what should be a tiny fix, but unfortunately if you need to have simultaneous requests each loading a session then it is required.
NOTE if your ajax or resource delivery script does actually need to write/save data, then you need to do it somewhere other than in the session, like database.
Just put session_write_close(); befor Session_start();
as below:
<?php
session_write_close();
session_start();
.....
?>
I don't know why, but changing this value in /etc/php/7.4/apache2/php.ini worked for me:
;session.save_path = "/var/lib/php/sessions"
session.save_path = "/tmp"
To throw another answer into the mix for those going bananas, I had a session_start() dying only in particular cases and scripts. The reason my session was dying was ultimately because I was storing a lot of data in them after a particularly intensive script, and ultimately the call to session_start() was exhausting the 'memory_limit' setting in php.ini.
After increasing 'memory_limit', those session_start() calls no longer killed my script.
For me, the problem seemed to originate from SeLinux. The needed command was chcon -R -t httpd_sys_content_t [www directory] to give access to the right directory.
See https://askubuntu.com/questions/451922/apache-access-denied-because-search-permissions-are-missing
If you use pgAdmin 4 this can happen as well.
If you have File > Preferences > SQL Editor > Options > "Auto Commit" disabled, and you just ran a query using the query tool but didn't manually commit, then session_start() will freeze.
Enable auto commit, or manually commit, or just close pgAdmin, and it will no longer freeze.
In my case it seems like it was the NFS Share that was locking the session , after restarting the NFS server and only enabled 1 node of web clients the sessions worked normally .
Yet another few cents that might help someone. In my case I was storing in $_SESSION complex data with several different class objects in them and session_start() couldn't handle the whole unserialization as not every class was loaded on session_start. The solution is my case was to serialize/jsonify data before saving it into the $_SESSION and reversing the process after I got the data out of session.

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