$ who
	ycos     tty1         Jul  8 09:47
	ycos     pts/0        Jul  8 09:48
	ycos     pts/1        Jul  8 09:57
	ycos     pts/2        Jul  8 13:02
	student  pts/3        Jul  8 13:03 (h196.s17.la.net)

	$ who am i
	ycos     pts/1        Jul  8 09:57
	$ who are you
	ycos     pts/1        Jul  8 09:57
	# 余談ですが、引数が2つあれば何でも who am i 動作になります。

	$ who -Hu
	名前     端末         時間         IDLE          PID コメント
	ycos     tty1         Jul  8 09:47 03:18         540
	ycos     pts/0        Jul  8 09:48 00:01         719
	ycos     pts/1        Jul  8 09:57   .           805
	ycos     pts/2        Jul  8 13:02 00:02        1789
	student  pts/3        Jul  8 13:03 00:02        1877 (h196.s17.la.net)

	$ w
	 13:17:25  up  3:33,  5 users,  load average: 0.02, 0.11, 0.08
	USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU  WHAT
	ycos     tty1     -                 9:47am  3:29m  2.66s  0.03s  /bin/sh /usr/X1
	ycos     pts/0    -                 9:48am  2:40   6.86s  6.30s  vim index.html
	ycos     pts/1    -                 9:57am  0.00s  0.90s  0.01s  w
	ycos     pts/2    -                 1:02pm 18.00s  0.11s  0.11s  /bin/bash
	student  pts/3    h196.s17.la.net   1:03pm 13:33   0.02s  0.02s  -bash

$ w -shf
ycos     tty1       3:36m  /bin/sh /usr/X11R6/bin/startx
ycos     pts/0     26.00s  vim index.html
ycos     pts/1      0.00s  w -shf
ycos     pts/2      4:40   man w
student  pts/3     20:49   -bash

$ w student
 13:18:40  up  3:34,  5 users,  load average: 0.49, 0.21, 0.12
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU  WHAT
student  pts/3    h196.s17.la.net   1:03pm 14:48   0.02s  0.02s  -bash