Copyright 1989 AT&T
Copyright (c) 2000, Sun Microsystems, Inc. All Rights Reserved
Portions Copyright (c) 1992, X/Open Company Limited All Rights Reserved
Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.
The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
This notice shall appear on any product containing this material.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
/usr/bin/who [-abdHlmpqrstTu] [file]
/usr/bin/who -q [-n x] [file]
/usr/bin/who am i
/usr/bin/who am I
/usr/xpg4/bin/who [-abdHlmpqrtTu] [file]
/usr/xpg4/bin/who -q [-n x] [file]
/usr/xpg4/bin/who -s [-bdHlmpqrtu] [file]
/usr/xpg4/bin/who am i
/usr/xpg4/bin/who am I
The who utility can list the user's name, terminal line, login time, elapsed time since activity occurred on the line, and the process-ID of the command interpreter (shell) for each current UNIX system user. It examines the /var/adm/utmpx file to obtain its information. If file is given, that file (which must be in utmpx(4) format) is examined. Usually, file will be /var/adm/wtmpx, which contains a history of all the logins since the file was last created.
The general format for output is:
name [state] line time [idle] [pid] [comment] [exit]
where:
name
User's login name
state
Capability of writing to the terminal
line
Name of the line found in /dev
time
Time since user's login
idle
Time elapsed since the user's last activity
pid
User's process id
comment
Comment line in inittab(4)
exit
Exit status for dead processes
The following options are supported:
-a
Processes /var/adm/utmpx or the named file with -b, -d, -l, -p, -r, -t, -T, and -u options turned on.
-b
Indicates the time and date of the last reboot.
-d
Displays all processes that have expired and not been respawned by init. The exit field appears for dead processes and contains the termination and exit values (as returned by wait(3UCB)), of the dead process. This can be useful in determining why a process terminated.
-H
Outputs column headings above the regular output.
-l
Lists only those lines on which the system is waiting for someone to login. The name field is LOGIN in such cases. Other fields are the same as for user entries except that the state field does not exist.
-m
Outputs only information about the current terminal.
-n x
Takes a numeric argument, x, which specifies the number of users to display per line. x must be at least 1. The -n option can only be used with -q.
-p
Lists any other process that is currently active and has been previously spawned by init. The name field is the name of the program executed by init as found in /sbin/inittab. The state, line, and idle fields have no meaning. The comment field shows the id field of the line from /sbin/inittab that spawned this process. See inittab(4).
-q
(Quick who) Displays only the names and the number of users currently logged on. When this option is used, all other options are ignored.
-r
Indicates the current run-level of the init process.
-s
(Default) Lists only the name, line, and time fields.
-T
Same as the -s option, except that the state idle, pid, and comment, fields are also written. state is one of the following characters:
+
The terminal allows write access to other users.
-
The terminal denies write access to other users.
?
The terminal write-access state cannot be determined.
-T
Same as the -s option, except that the state field is also written. state is one of the characters listed under the /usr/bin/who version of this option. If the -u option is used with -T, the idle time is added to the end of the previous format.
-t
Indicates the last change to the system clock (using the date utility) by root. See su(1M) and date(1).
-u
Lists only those users who are currently logged in. The name is the user's login name. The line is the name of the line as found in the directory /dev. The time is the time that the user logged in. The idle column contains the number of hours and minutes since activity last occurred on that particular line. A dot (.) indicates that the terminal has seen activity in the last minute and is therefore ``current.'' If more than twenty-four hours have elapsed or the line has not been used since boot time, the entry is marked old. This field is useful when trying to determine whether a person is working at the terminal or not. The pid is the process-ID of the user's shell. The comment is the comment field associated with this line as found in /sbin/inittab (see inittab(4)). This can contain information about where the terminal is located, the telephone number of the dataset, type of terminal if hard-wired, and so forth.
The following operands are supported:
am i
am I
In the "C" locale, limits the output to describing the invoking user, equivalent to the -m option. The am and i or I must be separate arguments.
file
Specifies a path name of a file to substitute for the database of logged-on users that who uses by default.
See environ(5) for descriptions of the following environment variables that affect the execution of who: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, LC_TIME, and NLSPATH.
The following exit values are returned:
0
Successful completion.
>0
An error occurred.
Script for init
Current user and accounting information
Historic user and accounting information
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Interface Stability | Standard |
date(1), login(1), mesg(1), init(1M), su(1M), wait(3UCB), inittab(4), utmpx(4), attributes(5), environ(5), standards(5)
Superuser: After a shutdown to the single-user state, who returns a prompt. Since /var/adm/utmpx is updated at login time and there is no login in single-user state, who cannot report accurately on this state. The command, who am i, however, returns the correct information.