Detecting a computer

[liamoco]

On my website I really do not want the user to be logged in more than once, My idea is to store the IP address of the user when he/she logs in, but the IP address will be the same if the user logs in from two different devices in the same location (house for example), how can I detect each individual computer. If my logic is wrong please, inform me with a better way of doing this.

 

Thanks

[trq]

how can I detect each individual computer.

 

You can't.

[liamoco]

OK now I know that isn't possible, any ideas? Lets say a user logs into my website on Google Chrome, but the user wants to log in twice, so the user decides to use Firefox to log in again, I do not want multiple logins, so I want the user to log into the website on Firefox but at the same time logged out of Chrome. Im thinking a lot a ajax is needed? Please help.

 

Thanks

[Philip]

Use keys stored in session/cookie/whatever, that match up with the same on the server (e.g. database.) Once a user logs in elsewhere, the key is invalid and they are logged out.

[The Little Guy]

When they log in using chrome set a database value to 1.

If they open up another browser, and log in from that browser check to see if they the value is 1.

If it is 1 don't let them login.

 

You will also need to track activity of the user and every 5 - 15 minutes run a cron to automatically log out users that have exceed the 5 - 15 minute inactivity time limit, resetting 1 back to 0.

 

There are some downsides to this:

1. if the user accidently closes his/her browser their session ends and when they try to log back in they can till the cron runs again. So, you may need to find a work around for this (such as an ajax onunload).

2. users are required to log in again if they leave their computer for more than the inactivity time and come back.