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SubjectRe: How can I know the number of current users in the system?
Absolutly true. 

You can get a 90% solution by testing for tty and for proces that has a
connection to a tcp port between 6000 and 6100 somewhere or has a unix
socket to /tmp/.X11-unix/X0 (or whereever X chooses to place the unix

But thats definitly not good enough to base your scheduling on.


tir, 2001-11-06 kl. 13:38 skrev 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.


> 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.


Terje Eggestad
Scali Scalable Linux Systems

Olaf Helsets Vei 6 tel: +47 22 62 89 61 (OFFICE)
P.O.Box 70 Bogerud +47 975 31 574 (MOBILE)
N-0621 Oslo fax: +47 22 62 89 51

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