Re: How can I know the number of current users in the system?

[Nicholas Berry]

It depends whether you're looking for an idea of who's on, or you want a definitive count. The lattter is basically almost impossible. What if a logged-in user nohups two xterms to different X-servers, then logs out - how many people are logged in? I've spent a hell of a long time working on this on AIX for a certain German bank, and the bottom line is that it can't be done. What is 'logged on' anyway? Someone running bash or ksh, that's cool, but what about someone running /home/fred/myprog? Is it a shell?

Basically once Unix went beyond serial terminals connected to dumb serial ports, we lost the ability to track users.

Nik

> Hmmm, you should be able to count the number of pty's and tty's.
> Every logged in user is attached to some sort of getty
> whose parent is the init task (1). That might be a basis for
> a count.