who - who is on the system
/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 exam-
ined. 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]
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 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.
-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 deter-
-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 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 attri-
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Availability | SUNWcsu |
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Availability | SUNWxcu4 |
| Interface Stability | Standard |
date(1), login(1), mesg(1), init(1M), su(1M), wait(3UCB),
inittab(4), utmpx(4), attributes(5), environ(5), stan-
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, how-
ever, returns the correct information.
Man(1) output converted with