W(1)

NAME
w, uptime - who is on and what they are doing; system time up

SYNOPSIS
w [ -hswu ] [ user ]
uptime

DESCRIPTION
W prints a summary of the current activity on the system, including what each user is doing.

The uptime invocation prints only the header line.

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 output are: the users login name, the name of the tty the user is on, 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.

The -h flag suppresses the heading. The -s flag asks for 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.

The -w and -u flags force the w and uptime actions respectively, regardless of the name the program is invoked as.

If a user name is included, the output will be restricted to that user.

FILES
/var/run/utmp    for login names
/dev/swap    secondary storage

SEE ALSO
finger(1), ps(1), who(1)

AUTHOR
Mark Horton

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 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 processs 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.