[ILUG] set watch(..) under bash

[McDaid, Aaron]

> tcsh has the ability to monitor certain users logging on and 
> off using:
> set watch(1 username1 any username2 any)
> I have looked all over the place but haven't found anything 
> similair under
> bash. Does anyone know the command?

There is a command on my machine called watch
which is kinda like this but it's too interactive,
so to speak. It watches the output of any command
changing. If you type "watch who" it gets in your
way. I have RTFM for a switch that stays completely
quiet until there's a change but no luck

This is overkill but!

#!/bin/bash
(who|cut -d " " -f1|sort|uniq)>new
while (true) do
cp new old
(who|cut -d " " -f1|sort|uniq)>new
diff new old
done

save that as /usr/local/bin/watch and make it executable.
run it in the background ie.
bash# watch &
and whenever someone logs in or out it'll
print it on that terminal while letting you
get on with your work in that terminal

Is there an easy way with the bash to get
a temporary (ie. unique) filename. I don't
want my prog to delete files called "new"
and "old" that may already exist

PS: remove the |sort|uniq if you want to see
all logins (even if that user is already logged
in)