Knowing who is logged where

[Logan 2]

Hello
I try to make a script to let me know a user who is connected on which machine. The idea is to avoid me having to make all rooms info when I was looking for someone. This is the final script, to call an argument with the person sought. Here machines are called up 01 MACHINE MACHINE 42.

/ bin / bash

(function pqui
users = $ (ssh MACHINE-$ 1 users)
result = ""
for user in $ users
do
ssh MACHINE-$ 1 w-s | egrep-q "$ user [[: blank:]] * tty7" & & result = $ result "$ user"
done
if [[! -z $ result]]
then
echo "MACHINE-$ 1: $ result
fi
)

for i in $ (seq-f '% 02g' $ 1 NBPC);
do
pqui $ i &
done
wait
exit 0;

I have several problems.
- How to make a single loop from 01 to 42? (for the moment I go from 1 to 9 zeros and then adding 10 to 42)
- How to tell if a user is physically connected? (if I move and there's nobody my script has no interest)
- How do nothing if no one is displayed on the machine?
For the last 2 items I did not find anything by reading the man users. Basically users uses / var / run / utmp, but this file is unreadable. Thank you in advance.

[kelfro]

Hi,
I think you should modify your for loop, in this way

for ((i = 1; i <= 42; i + +))
do
MACHINE echo $ (printf "% 02d \ n" "$ i")
done

This will be more effective than the current one in your code.

[Reegan]

Hello

How to make a single loop from 01 to 42?

for i in $ (seq-f '% 02g' 1 42);

How do I know if a user is physically connected?

I advise you to use the BSD finger command.

sudo apt-get install bsd-finger

It would obviously be installed on each machine but you can do with an order by combining ssh apt-get, yes, and a small loop.

for user in $ (MACHINE ssh $ i-0 users)
do
$ result = $ (finger-s $ user)
...

Hope this will help you.

[MindSpace]

Hello,

How to display nothing if nobody is on the machine?

result = $ (MACHINE ssh $ i-0 users)
if [[! -z $ result]]
  then echo $ result
fi

[[]] Is a shortcut for calling the test command. I invite you to read the documentation for this command: man test.
Finally, the code should look like this:

for i in $ (seq-f '% 02g' 1 42)
do
   users = $ (MACHINE ssh $ i-0 users)
   for user in $ users
   do
      $ result = (finger-s $ user)

   done
done

You must use the command awk and grep to parse the result returned by finger.

[Modifier]

Hello
I found better than the finger command. The command w which is already available. Needless to install finger.
The code now becomes:

for i in $ (seq-f '% 02g' 1 42)
do
   users = $ (MACHINE ssh $ i-0 users)
   for user in $ users
   do
      result = $ (w-s | grep $ user)

   done
done

This may make your code better and easier to read.

[kelfro]

Hello
I think there is no need to install any thing, this is unnecessary. Just have a look at the following code.

# '/ usr / bin / env bash

for i in machine1 machine2
do
    Who ssh $ i 2> / dev / null | egrep-q "^ $ 1 [[: blank:]] * tty7" & & (notify-send 'found' "$ i"; found on echo $ i) &
done

# wait
exit 0

I put each ssh in background to avoid waiting the end of each connection
- Script starts with the user name as argument
- Adapting to your loop for hostnames
- Of course we can turn the notify-send if no interface Graphic
- The wait (commented here) used to wait until all the ssh connections in the background to close the script, it is obviously necessary to connect ssh key if not impossible to enter the pass.