Unix Power ToolsUnix Power ToolsSearch this book

2.8. Who's On?

The who command lists the users logged on to the system now. Here's an example of the output on my system:

% who
naylor   ttyZ1   Nov  6 08:25
hal      ttyp0   Oct 20 16:04   (zebra.ora.com:0.)
pmui     ttyp1   Nov  4 17:21   (dud.ora.com:0.0)
jpeek    ttyp2   Nov  5 23:08   (jpeek.com)
hal      ttyp3   Oct 28 15:43   (zebra.ora.com:0.)
    ...

Each line shows a different terminal or window. The columns show the username logged on, the tty (Section 2.7) number, the login time, and, if the user is coming in via a network (Section 1.21), you'll see their location (in parentheses). The user hal is logged on twice, for instance.

It's handy to search the output of who with grep (Section 13.1) -- especially on systems with a lot of users. For example:

% who | grep "^hal "             ...where is hal logged on?
% who | grep "Nov  6"            ...who logged on today?

-v Section 13.3

% who | grep -v "Nov  6"         ...who logged on before today?
    ...

The GNU who, on the CD-ROM [see http://examples.oreilly.com/upt3], has more features than some other versions.

-- JP



Library Navigation Links

Copyright © 2003 O'Reilly & Associates. All rights reserved.