The command w on many Unix-like operating systems provides a quick summary of every user logged into a computer, what each user is currently doing, and what load all the activity is imposing on the computer itself. The command is a one-command combination of several other Unix programs: who, uptime, and ps -a.
Example
Sample output (which may vary between systems):
$ w 11:12am up 608 day(s), 19:56, 6 users, load average: 0.36, 0.36, 0.37User tty login@ idle whatsmithj pts/5 8:52am wjonesm pts/23 20Apr06 28 -bashharry pts/18 9:01am 9 pinepeterb pts/19 21Apr06 emacs -nw html/index.htmljanetmcq pts/8 10:12am 3days -cshsingh pts/12 16Apr06 5:29 /usr/bin/perl -w perl/test/program.plReferences
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