The w command

Yaser Rahmati | یاسر رحمتی

The w command displays information about the users that are currently active on the machine and their processes.

Examples:

Running the w command without arguments shows a list of logged on users and their processes.

[root@academy mydir]# w
 19:33:16 up  4:11,  2 users,  load average: 0.06, 0.10, 0.08
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
root     pts/0    192.168.73.1     18:42    4.00s  0.56s  0.02s w
apa      pts/1    192.168.73.1     19:28    4:36   0.01s  0.01s -bash
[root@academy mydir]#

Show information for the user named apa.

[root@academy mydir]# w apa
 19:33:47 up  4:11,  2 users,  load average: 0.04, 0.09, 0.07
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
apa      pts/1    192.168.73.1     19:28    5:07   0.01s  0.01s -bash
[root@academy mydir]#

Additional Information

The header of the output 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 they are
logged in from the amount of time they are logged in their
idle time JCPU
PCPU
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.

Additional Flags and their Functionalities:

Short Flag Long Flag Description

Short Flag	Long Flag	Description
-u	--no-current	Ignores the username while figuring out the current process and cpu times. (To see an example of this, switch to the root user with `su` and then run both `w` and `w -u`.)
-s	--short	Display abbreviated output (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 where the from field is shown by default.
--help	-	Display a help message, and exit.
-V	--version	Display version information, and exit.
-o	--old-style	Old style output (prints blank space for idle times less than one minute).
user	-	Show information about the specified the user only.

-u

--no-current

Ignores the username while figuring out the current process and cpu times. (To see an example of this, switch to the root user with su and then run both w and w -u.)

-s

--short

Display abbreviated output (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 where the from field is shown by default.

--help

Display a help message, and exit.

-V

--version

Display version information, and exit.

-o

--old-style

Old style output (prints blank space for idle times less than one minute).

user

Show information about the specified the user only.