what is this?
w -- display who is logged in and what they are doing
god!
bash-4.4$ w
6:51 up 11 days, 3:59, 5 users, load averages: 1.72 1.39 1.40
USER TTY FROM LOGIN@ IDLE WHAT
yuma console - 20Aug18 11days -
yuma s000 - Thu02 22:19 -zsh
yuma s002 - Thu17 2 /usr/local/bin/vim test
yuma s003 - 6:45 - w
yuma s004 - Thu18 12:26 bash
bash-4.4$ man w | cat
W(1) BSD General Commands Manual W(1)
NAME
w -- display who is logged in and what they are doing
SYNOPSIS
w [-hin] [user ...]
DESCRIPTION
The w utility prints a summary of the current activity on the system,
including what each user is doing. The first line displays the current
time of day, how long the system has been running, the number of users
logged into the system, and the load averages. The load average numbers
give the number of jobs in the run queue averaged over 1, 5 and 15 min-
utes.
The fields output are the user's login name, the name of the terminal the
user is on, the host from which the user is logged in, the time the user
logged on, the time since the user last typed anything, and the name and
arguments of the current process.
The options are as follows:
-h Suppress the heading.
-i Output is sorted by idle time.
If one or more user names are specified, the output is restricted to
those users.
COMPATIBILITY
The -M, -d, -f, -l, -n, -s, and -w flags are no longer supported.
SEE ALSO
finger(1), ps(1), uptime(1), who(1)
HISTORY
The w command appeared in 3.0BSD.
BUGS
The notion of the ``current process'' is muddy. The current algorithm 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 back-
ground fork and fail to ignore interrupts. (In cases where no process
can be found, w 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 command is
printed in parentheses.
The w utility does not know about the new conventions for detection of
background jobs. It will sometimes find a background job instead of the
right one.
Long hostnames and IPv6 addresses may be truncated; however, the who(1)
utility will display full hostnames.
BSD June 6, 1993 BSD