script : How many sessions are there ?

xaviraan · 06-10-2009, 02:43 PM

Hi everybody,

I need a script that shows the total number of sessions there are ...

This shows how many sessions are open...

Code:

 echo "Number of open sessions: "
  w | grep :0 | wc | awk '{print $1}

But how can I see how many sessions there are in total??
I hope someone can help me...

Grtz

Tinkster · 06-10-2009, 03:26 PM

Hi grtz,
welcome to LQ!

How do you define a "session", what discriminates an open session
from which other kind of session?

And I'm fairly certain that the snippet above doesn't provide
the information you believe it does. How does grepping idle
times for ":0" qualify for a open session?

Code:

w | grep :0
tink    pts/0    -                Fri09   17:03m  0.16s  0.16s bash

Cheers,
Tink

MensaWater · 06-10-2009, 03:27 PM

Based on that definition of "session":

Code:

 w |egrep -v "load average|USER" |wc -l

The -l argument of wc tells it to give you number of lines only.

David the H. · 06-10-2009, 03:40 PM

I'm not sure about how to answer your question, but I found a couple of problems with the command you posted.

In short, grepping for :0 is not an accurate way to list users. If a user is logged into a tty terminal then there won't be a :0 listed. Also, I just tried to run it, and I matched a line with an idle time of "2:07" as well. A better one would list all lines from w after the first two. Something like this:

Code:

w|sed -n '3,$p'|wc| awk '{print $1}'

I'll bet you also find a solution using just awk, too, but I don't have the energy to work it out myself right now. :P

Edit: beaten to the punch again.

xaviraan · 06-10-2009, 03:52 PM

Thanks, jlightner! I think that's what I need

And thanks also for the upgrade of my code, David!!

grtz

Tinkster · 06-10-2009, 03:59 PM

Quote:

Originally Posted by David the H.

I'll bet you also find a solution using just awk, too, but I don't have the energy to work it out myself right now. :P

;}

Code:

w | awk 'END{print NR-2}'

Cheers,
Tink

David the H. · 06-10-2009, 04:17 PM

Thanks Tinkster. I knew it had to be something easy like that. I was using the same "print NR-2" expression as yours, but couldn't figure out how to get it to output only the last record number. I didn't think to put it in the END statement. How simple.

MensaWater · 06-11-2009, 09:24 AM

Quote:

Originally Posted by xaviraan

Thanks, jlightner! I think that's what I need

And thanks also for the upgrade of my code, David!!

grtz

No problem.

By the way - if you click the little thumbs up ICON on the posts David and I made we'll be "officially" thanked for the record.

colucix · 06-11-2009, 09:30 AM

Another option:

Code:

users | wc -w