··· NAME w - Show who is logged on and what they are doing.
The w command is used to show who is logging in and what they are doing.
DESCRIPTION w displays information about the users currently on the machine, and their processes. The header shows, in this order, the current time, how long the system has been running, how many users are currently logged on, and the system load averages for the past 1, 5, and 15 minutes. The following entries are displayed for each user: login name, the tty name, the remote host, login time, idle time, JCPU, PCPU, and the command line of their current process. The JCPU time is the time used by all processes attached to the tty. It does not include past background jobs, but does include currently running background jobs. The PCPU time is the time used by the current process, named in the "what" field.
w describes the users currently on the machine and their processes. The beginning of the line will show in the following order: the current time, how long the system has been running, how many users are logging in the current system, and the average load of the system in the past 1, 5, 15 minutes.
The next entries show each user: login name, tty name, remote (login) host, login time, idle time, JCPU, PCPU, and the command line of the current process.
JCPU time is the usage time attached to all processes. It does not include past daemons, but it includes the currently running daemons. [not quite understood]
PCPU time is the time used by the current thread and is shown in the what domain.
```shell COMMAND-LINE OPTIONS -h, --no-header Don't print the header. -u, --no-current Ignores the username while figuring out the current process and cpu times. To demonstrate this, do a "su" and do a "w" and a "w -u". -s, --short Use the short format. Don't print the login time, JCPU or PCPU times. -f, --from Toggle printing the from (remote hostname) field. The default as released is for the from field to not be printed, although your system administrator or distribution maintainer may have compiled a version in which the from field is shown by default. --help Display help text and exit. -i, --ip-addr Display IP address instead of hostname for from field. -V, --version Display version information. -o, --old-style Old style output. Prints blank space for idle times less than one minute. user Show information about the specified user only.