WHO(1)WHO(1)NAMEwho - who is on the system
SYNOPSIS
/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
DESCRIPTION
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. Usu‐
ally, 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
OPTIONS
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 deter‐
mining 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.
/usr/bin/who
-T
Same as the -s option, except that the state idle, pid, and com‐
ment, 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.
/usr/xpg4/bin/who
-T
Same as the -s option, except that the state field is also writ‐
ten. 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 for‐
mat.
-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 deter‐
mine 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 com‐
ment 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.
OPERANDS
The following operands are supported:
am i
am I
In the "C" locale, limits the output to describing the invok‐
ing 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.
ENVIRONMENT VARIABLES
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.
EXIT STATUS
The following exit values are returned:
0
Successful completion.
>0
An error occurred.
FILES
/sbin/inittab
Script for init
/var/adm/utmpx
Current user and accounting information
/var/adm/wtmpx
Historic user and accounting information
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
/usr/xpg4/bin/who
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Interface Stability │ Standard │
└────────────────────┴─────────────────┘
SEE ALSOdate(1), login(1), mesg(1), init(1M), su(1M), wait(3UCB), inittab(4),
utmpx(4), attributes(5), environ(5), standards(5)NOTES
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.
Nov 3, 2000 WHO(1)
