w(C)

w, uptime -- display information about who is on the system and what they are doing

Synopsis

w [-hls] [user]

uptime

Description

w- display information about who is on the system and what they are doing

uptime- display summary information about system activity

The uptime command and the heading line on the w command are the same and show the current time of day, how long the system has been up, the number of users logged onto the system, and load averages. Load averages are shown as three numbers, reflecting an average over 1, 5, and 15 minute intervals. By default, load averages reflect the number of processes in the run queue.

The w command 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, and the number of users logged into the system.

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.

The following options are available:

-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.

Example

Executing w with no options produces output similar to the following:

   7:36am  up 6 days, 16:45,  1 user
   User    tty     login@  idle    JCPU    PCPU    what
   ralph   console 7:10am     1    10:05   4:31    w

Files

/var/adm/utmp

References

ps(C), utmp(F), who(C), whodo(ADM)

Notes

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 background 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.

w does not know about the conventions for detecting background jobs. It will sometimes find a background job instead of the right one.

Unlike other BSD versions of this command, the load averages are not computed or displayed.