w.procps

w [options] [user]

-h
    Suppresses the header display.

-l
    Use long format. Display the login time, idle time, JCPU and PCPU times. The default format is short.

-s
    Use short format. Suppress the login time, idle time, JCPU and PCPU times.

-u
    Ignore the user's name when figuring out the current process and CPU time. To get the true CPU time, make w read the /proc file directly rather than using utmp/wtmp files.

-i
    Display the user's idle time as a number of minutes, rather than in `Xd+Yh+Zm+Zs' format.

-V
    Display version information and exit.

-f
    Show the user's from-machine (hostname) as well as the username.

user
    Show information about a specific user. If no user is specified, shows information about all logged-in users.

The w command provides a concise summary of what the system is doing. It displays information about currently logged-in users and their processes. The header shows the current time, the system uptime, and the average system load averages. For each user, w shows the login name, the terminal line, the remote host, the login time, idle time, JCPU (CPU time used by all processes attached to the tty), PCPU (CPU time used by the current process), and the command line of their current process. The information can be useful for monitoring system activity and identifying potential resource bottlenecks. The command's output is formatted for easy readability in a terminal, providing a quick overview of user activity.

The w command might not display precise idle times due to system process scheduling and how the kernel tracks terminal activity.

who(1), uptime(1), ps(1), top(1)