w(1)w(1)Namew - display who is logged in and what they are doing
Syntaxw [ options ] [user]
Description
The command prints a summary of the current activity on the system,
including what each user is doing. The heading line shows the current
time of day, how long the system has been up, the number of users
logged into the system, and the load averages. The load average num‐
bers give the number of jobs in the run queue averaged over 1, 5 and 15
minutes.
The fields output are:
The users login name
The name of the tty the user is on
The host from which the user is logged in
The time of day the user logged on
The number of minutes since the user last typed anything
The CPU time used by all processes and their children on that terminal
The CPU time used by the currently active processes
The name and arguments of the current process
Options-d Outputs debug information.
-f Suppresses the `from' field.
-h Suppresses the normal header from the output.
-l Displays information in long format (default).
-s Displays information in short format. In the short form, the tty is
abbreviated, the login time and cpu times are left off, as are the
arguments to commands.
-u Outputs the same information as the command.
If a user name is included, the output will be restricted to that
user.
Restrictions
The notion of the ``current process'' is unclear. The current algo‐
rithm is ``the highest numbered process on the terminal that is not
ignoring interrupts, or, if there is none, the highest numbered process
on the terminal''. This fails, for example, in critical sections of
programs like the shell and editor, or when faulty programs running in
the background fork and fail to ignore interrupts. (In cases where no
process can be found, prints ``-''.)
The CPU time is only an estimate, in particular, if someone leaves a
background process running after logging out, the person currently on
that terminal is ``charged'' with the time.
Background processes are not shown, even though they account for much
of the load on the system.
Sometimes processes, typically those in the background, are printed
with null or garbaged arguments. In these cases, the name of the com‐
mand is printed in parentheses.
The command does not know about conventions for detection of background
jobs. It will sometimes find a background job instead of the right
one.
Files
/etc/utmp
/dev/kmem
/dev/drum
See Alsofinger(1), ps(1), who(1)w(1)