The output line is from who -u and the man page is helpful:
"-u Lists only those users who are currently logged in. name is the user's login name. line is the name of the line as found in the directory /dev. The time field indicates when the user logged in. activity is the number of hours and minutes since input activity last occurred on that particular line. A dot (.) indicates that the terminal has seen activity in the last minute and is therefore ``current''. If more than twenty-four hours have elapsed or the line has not been used since boot time, the entry is marked old. This field is useful when trying to determine whether a person is working at the terminal or not."
> ** what does status old mean?
The user has been logged in but no terminal activity for more than 24 hours.
> kill -9 .. doesn't work
That is quite normal for a process that is hung on an I/O (almost always networking) that will never complete. kill doesn't actually stop a program. Instead, it sets a flag (a signal) in the program's process table and the next moment that the program starts running again, the signal will be processed. All signals except -9 can be handled (trapped) by a program. For kill -9, the program will terminate unconditionally when the program starts the next instruction.
So until the process (9540) completes the I/O, it will hang forever. NOTE: it consumes no resources in the system. There is an entry in the process table but it has been suspended. So ignore the process and the associated user.
> ps -elf | grep 9540
> ps -ef|grep $1|grep user| awk '{ print $2; }'|xargs kill -9
Please, don't use grep with ps!!! The first example will find PID 9540 but also find PID 19540 and command line values such as abc9540zz or index:195400. If you kill everything returned by this grep, you'll break unrelated processes. You will get an EXACT match with ps. The man page is very helpful:
ps -lfp 9540
ps reads the process table knows exactly which process is 9540.
The second example is even more dangerous as it uses grep for a particular user but it will find the user's ID in many different locations on the line -- grep has no concept of a field or column. Again, ps knows exactly how to find a specific user:
ps -flu jarhadta
But remember that ps will find all processes owned by that user ID. As mentioned, there are other processes owned by this user that are not to be terminated.
But there are also many other unused options for ps, specifically -H, -C and -o. -H shows processes sorted and indented based on hierarchy, so each process tree can be seen. -C matches an exact process name (no grep), and -o eliminates the need for awk to parse the line by showing just the desired fields. NOTE: all of these options require temporary setting of the UNIX95 variable so to find all sh processes use this (exactly as shown):
UNIX95=1 ps -fC sh
compare that with:
ps -ef | grep sh
Lots of mistakes with grep...
Also try this:
UNIX95=1 ps -efH
shows all processes sorted by hierarchy (parent - child). You can combine _H with other selections like user ID:
UNIX95=1 ps -fHu billh
Bill Hassell, sysadmin
