who(1) DG/UX R4.11 who(1)
NAME
who - who is on the system
SYNOPSIS
who [ -uTHlpdbrtasqh ] [ file ]
who -qn x [ file ]
who am i
who am I
DESCRIPTION
Who can list the user's name, terminal line, login time, elapsed time
since activity occurred on the line, and the process ID of the shell
for each current system user. It examines the /etc/utmp file to get
this information, or it examines file if it is given. 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 from
this command is:
name [state] line time activity pid [comment] [exit]
[hostname]
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:
-u Lists only those users 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
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 /etc/inittab (see inittab(4)). This can contain
information such as where the terminal is located, the
telephone number of the dataset, and the type of terminal if it
is hard-wired.
-T Same as 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 + appears if the terminal is
writable by anyone; a - appears if it is not. Users with
appropriate privilege can write to all lines having a + or a -
in the state field. If a bad line is encountered, a ? is
printed.
-l Lists only those lines on which the system is waiting for
someone to login. The name field in this case is LOGIN. Other
fields are the same as for user entries, except that the state
field does not exist. See Notes Section below.
-p Lists any other active process that was also spawned by init.
The name field is the name of the program executed by init as
found in /etc/inittab. The state, line, and activity fields
have no meaning. The comment field shows the id field of the
line from /etc/inittab that spawned this process. See
inittab(4).
-d Displays all processes that have expired and not been respawned
by init. The exit field appears for a dead process and
contains its termination and exit values, as returned by
wait(2) . This can be useful in determining why a process
terminated.
-b Indicates the time and date of the last reboot.
-r Indicates the current run-level of the init process.
-t Indicates the last change to the system clock (via the date(1)
command) by a user with approriate privilege. See su(1).
-a Processes /etc/utmp or the named file with all options turned
on.
-s The default--lists only the name, line, and time fields.
-H Prints column headings above the regular output.
-q This is a quick who, displaying only the names and the number
of users currently logged on. When this option is used, all
other options except n are ignored.
-n x This option should be used with -q. It lets you specify the
number of users you want to be displayed per line.
-h This option prints host names for remote users
EXAMPLES
$ who am i
user1 tty21 Nov 19 09:54
The above example displays the user who invoked the who command.
$ who -u
sysmgr tty01 Nov 19 09:00 1:53 690
donnelly tty02 Nov 19 08:56 0:20 144
crumley tty20 Nov 19 09:32 . 151
user1 tty21 Nov 19 09:54 . 974
user2 tty12 Nov 19 13:19 0:06 1728
The above example shows all users logged onto the system, which
terminal they have logged onto, the date and time, the amount of time
since last activity ("." indicates less than one minute), and the
user's PID.
$ who -b
. system boot Nov 18 21:34
The above example shows the date and time that the system was last
booted.
FILES
/etc/utmp
/etc/wtmp
/etc/inittab
SEE ALSO
date(1), login(1), mesg(1), ps(1), su(1).
wait(2), inittab(4), utmp(4)
init(1M)
NOTES
Currently the -l option does not list the lines on which the system
is waiting for someone to login. Instead it lists the utmp entries
for the active port monitors and any ports monitored by the ttymon
processes running in express mode where no login session has been
started. This is subject to change.
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