list who is on the system
[ -aAbdfHlmpqrstTux ] [ -n count ]
[ file ]
who am i
who am I
The who command can list the user's name, terminal line,
login time, and the elapsed time since activity occurred on the
line; it also lists the process ID of the command
interpreter (shell) for each current user. It examines the
/etc/inittab file to obtain information for the Comments
column, and /etc/utmp to obtain all other information. If
file is given, that file is examined. Usually,
file will be /etc/wtmp, which contains a history
of all the logins since the file was last created.
who with the am i or am I option
identifies the invoking user.
Except for the default -s option, the general format for
output entries is:
name [state] line time activity pid [comment] [exit]
With options, who can list logins, logoffs, reboots, and
changes to the system clock, as well as other processes spawned by
the init process. These options are:
Process the /etc/utmp file or the named file
with all options turned on.
Display UNIX accounting information.
Indicate the time and date of the last reboot.
Display all processes that have expired and have not been respawned
by init. The ``exit'' field appears for dead
processes and contains the termination and exit values (as returned
of the dead process. This can be useful in determining why a process
Suppress pseudo-ttys from who output, except for remote
Display column headings above the regular output.
List 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.
Equivalent to who am i.
count specifies the number of columns for the -q
option to use when displaying user names.
List any other process which 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
/etc/inittab. The ``state'', ``line'', and
``idle'' fields have no meaning. The ``comment'' field
shows the ``id'' field of the line from /etc/inittab
that spawned this process. See
Quick who; display only the names and the number of users
currently logged on. When this option is used, all other options are
Indicate the current run level of the init process, the
date and time at which this run level was entered, the current run
level (again), the number of times that the system has been at this
run level since last being rebooted, and the previous run level.
List only the ``name'', ``line'', and ``time''
fields. This is the default behavior of who.
Indicate the last change to the system clock (via the
command) by the root user. See
Equivalent to the -u option, except that the
``state'' of the terminal line is printed. The ``state''
describes whether someone else can write to that terminal. A plus
character (+) appears if the terminal is writable by anyone; a minus
character (-) appears if it is not. root can write to all
lines having a plus character or a minus character in the
``state'' field. If a bad line is encountered, a question mark
(?) is displayed.
List 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
``activity'' is 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
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. It can contain information about where the terminal
is located, the telephone number of the dataset, the type of
terminal if hard-wired, and so on.
Print the hostname. If file is not used to specify the
pathname of a
format file, who reads /etc/utmpx.
who returns 0 on successful completion. A value of 1
indicates that an error occurred; values greater than 1 correspond
to system errors documented in
Indicate when the system was last rebooted:
List those users currently logged in, and print a heading above the
extended version of /etc/utmp
extended version of /etc/wtmp
script read by the init process
who is conformant with:
ISO/IEC DIS 99452:1992, Information technology Portable Operating System Interface (POSIX) Part 2: Shell and Utilities (IEEE Std 1003.21992);
AT&T SVID Issue 2;
X/Open CAE Specification, Commands and Utilities, Issue 4, 1992.
© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 03 June 2005