W(1) General Commands Manual W(1)
w - who is logged in, and what are they doing
w [ -hls ] [ user ]
w displays 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 numbers give the
number of jobs in the run queue averaged over 1, 5 and 15 minutes.
The fields displayed are: the users login name, the name of the tty the
user is on, the time of day the user logged on (in hours:minutes), the
idle time -- that is, the number of minutes since the user last typed
anything (in hours:minutes), the CPU time used by all processes and
their children on that terminal (in minutes:seconds), the CPU time used
by the currently active processes (in minutes:seconds), the name and
arguments of the current process.
If a user name is included, output is restricted to that user.
-h Suppress the heading.
-l Produce a long form of output, which is the default.
-s Produce a short form of output. In the short form, the tty is
abbreviated, the login time and CPU times are left off, as are
the arguments to commands.
7:36am up 6 days, 16:45, 1 users, load average: 0.20, 0.23, 0.18
User tty login@ idle JCPU PCPU what
ralph console 7:10am 1 10:05 4:31 w
The environment variables LC_CTYPE, LANG, and LC_default control the
character classification throughout w. On entry to w, these environ-
ment variables are checked in the following order: LC_CTYPE, LANG, and
LC_default. When a valid value is found, remaining environment vari-
ables for character classification are ignored. For example, a new
setting for LANG does not override the current valid character classi-
fication rules of LC_CTYPE. When none of the values is valid, the
shell character classification defaults to the POSIX.1 "C" locale.
ps(1), who(1), utmp(5V)
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 com-
mand is printed in parentheses.
w does not know about the new conventions for detecting background
jobs. It will sometimes find a background job instead of the right
9 September 1987 W(1)