[SOLVED] Last active tty

[ekymk]

Hello,

My name is Marcelo and I am a student in computer science facing a project that is getting difficult to implement.

In order to solve some of my problems I would like to get some information.

I would like to know if it is possible in Linux to know from user space which is the last active tty attached to an user i choose(the last tty which had some activity in it). I will be root or some other user which will have the proper privileges. I am willing to do any combination of system calls and tricks.

If it is not possible to do from user space then I would like to do it myself inside the kernel. I need to know where should I start reading to have the knowledge required to do the changes in the kernel (in my local copy of course).

I have some knowledge of the kernel and some little experience in programming inside the kernel (mainly i played with the scheduler and the virtual memory).

Thank you in advance,

Marcelo Taube

[Krendoshazin]

This falls close to being a homework question, but I can give you a start and let you do the rest.
This command will show the tty's and their access date and time, this is what will show you the last active tty, to grab the right user it's a simple grep.

ls -lu /dev | grep tty | grep username

You may find there are several tty's listed, as a user could be using quite a few tty's at that point, so you'll need to find a way to grep the latest out of the list.

[smithyd]

hi, i did what you suggested but go this error, can you advice please?

[root@laptop ~]# ls -lu/dev |grep tty|grep root
ls: invalid option -- '/'
Try `ls --help' for more information.

thanks in advance

smithyd

[devils casper]

There is a space between -lu and /dev

ls -lu /dev | grep tty | grep username

[smithyd]

Thanks devils casper, that worked fine..Cheers