Asked  7 Months ago    Answers:  5   Viewed   33 times

Is there a way in PHP to get a list of all sessions (and the variables within each) on the server?

Basically, we have a maintenance function which needs to know which users are currently logged into the site. We already store data for each user in a session variable, but I am hoping that I can loop through each of these sessions and pluck out the data I need.

MY PHP is very limited (I am a .Net developer ussually) but if anyone knows if this is even possible (and how to do it) I'd be very grateful. I googled this, and the results I found tended to inidcate that it WASN'T possible, but I find this very hard to accept.

Still, If you can't you can't but I thought my buddies on StackOverflow could give me a definitive answer!



PHP stores session data for each user in a temporary folder on the server. This folder is defined in the php.ini configuration file under the variable session.save_path. Locate this value from within your php.ini file, or alternatively, create a php file with:

<?php echo "Session Save Path: " . ini_get( 'session.save_path');?>

as it's contents, and open the file in your browser.

Once you find the save path for the session data, open up that folder and you'll notice a fairly simple structure. All sessions are stored in the format: sess_$SESSIONID .

Session data is serialized before being stored on disk. As such, objects stored in the session file would have to be deserialized before being usable. However, if you're using plain text, which is stored as-is, to store your session data (ex. $_SESSION['userid'] = 1234) to store information about your users, it should be easy enough to parse out the data you're looking for from within the files.

One more thing ... I haven't looked into it, but it appears as though the session ID that appears in the filename corresponds directly to, for instance, the name of the PHPSESSID cookie stored on the user's computer. So, with this in mind, it may be possible to loop through the files within the temporary session directory, acquire all the $SESSIONID values, set the current session ID using session_id($SESSIONID), start a session with session_start() and access the data you need through PHP without having to parse the contents files themselves. Can anyone confirm whether or not this would be possible?

Edit: Adjusted post to match Itay's comment.

Wednesday, March 31, 2021
answered 7 Months ago

If this is just for debugging output, you can use the following to see all the types and values as well.


If you want more control over the output you can use this:

foreach ($obj as $key => $value) {
    echo "$key => $valuen";
Wednesday, March 31, 2021
answered 7 Months ago

the php-memcached extension supports session locking

the memcache and memcached extensions look syntactically similar so it may not be too much of a headache to give it a try. (memcached has a stable version 2.1.0 released 2012-08-07).

if you are set on using memcache 2.2.7 you will most likely have to implement the lock yourself by setting some "session_is_locked" variable in your session and then releasing/unsetting it when the script is done writing to the session. Then you'd always need to check if that variable is set before continuing with any scripts which write to the session.

Wednesday, March 31, 2021
answered 7 Months ago

You're best using the foreach construct to loop over your array. The following is untested and is off the top of my head (and probably therefore not as thought through as it should be!) but should give you a good start:

foreach ($mainArray as $event)
  print $event["eventTitle"];

  foreach ($event["artists"] as $artist)
     print $artist["name"];
     print $artist["description"];

     $links = array();
     foreach ($artist["links"] as $link)
       $links[] = $link["URL"];
     print implode(",", $links);
Thursday, June 3, 2021
answered 5 Months ago

session_destroy() destroys the active session. If you do not initialized the session, there will be nothing to be destroyed.

Thursday, July 29, 2021
answered 3 Months ago
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