who(1)

Synopsis

who -q [-n x] [file]

who am i

who am I

Description

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