who(1)
who --
who is on the system
Synopsis
who [-uTlLmHpdbrtas] [file]
who -q [-n 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 command interpreter (shell)
for each current UNIX system user.
It
examines the
/var/adm/utmp
file to obtain its information.
If file is given, that file
(which must be in
utmp(4)
format)
is examined.
Usually, file will be
/var/adm/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.
The general format for output is:
name [state] line time [idle] [pid] [comment] [exit]
The
name,
line,
and
time
information is produced by all options except
-q;
the
state
information is produced only by
-T;
the
idle
and
pid
information is produced only by
-u,
-l,
and
-T;
and
the
comment
and
exit
information is produced only by
-a.
The information produced for
-p,
-d,
and
-r
is explained during the discussion of each option, below.
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-
This option 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
/etc/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 on.
-T-
This option is the 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.
root
can write to all lines having a
``+''
or a
``-''
in the
``state''
field.
If a bad line is encountered, a
``?''
is printed.
-l-
This option lists 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.
If the environment variable POSIX2 is not set, running port
monitors are also listed (-L).
-L-
List all running port monitors.
-m-
Like
who am i ,
this option lists information for the invoking user only.
who -m
is equivalent to
who am i ,
with the exception that
-m
can be used in conjunction with other options.
-H-
This option will print 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.
-p-
This option lists 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
inittab(4).
-d-
This option displays processes
that have expired and have not been respawned by
init.
These include processes for lines on which the user has logged out.
The ``exit''
field appears for dead processes and contains the termination and exit
values
(as returned by
wait(2)),
of the dead process.
This can be useful in determining why a process
terminated.
The utmp entry for a dead process remains only
until the utmp entry is used for another process.
-b-
This option indicates the time and date of the last reboot.
-r-
This option shows the current
run-level
of the
init
process,
the number of times previously in that run-level,
and the prior run-level
under the idle, pid, and
comment
headings, respectively.
-t-
This option indicates the last
change to the system clock (via the
date
command) by
root
See
su(1M).
-a-
This option processes
/var/adm/utmp
or the named
file
with the -ulpdbrtTH options turned on.
-s-
This option is the default and lists only the
name,
line,
and
time
fields.
-n x-
This option takes a numeric argument, x, which specifies
the number of users to display per line.
x must be at least 1.
The -n option is ignored except when used with -q.
Files
/var/adm/wtmp-
/etc/inittab-
/var/adm/utmp-
/usr/lib/locale/locale/LC_MESSAGES/uxcore.abi-
language-specific message file
(See LANG in
environ(5).)
References
date(1),
init(1M),
inittab(4),
login(1),
mesg(1),
su(1M),
utmp(4),
wait(2)
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004