WHO(1)							    BSD General Commands Manual 						    WHO(1)

NAME

     who -- display who is logged in

SYNOPSIS

     who [-abdHlmqrstTuv] [file]
     who am i

DESCRIPTION

     The who utility displays a list of all users currently logged on, showing for each user the login name, tty name, the date and time of login,
     and hostname if not local.

     Available options:

     -a    Same as --bdlprTtuv.

     -b    Time of last system boot.

     -d    Print dead processes.

     -H    Write column headings above the regular output.

     -l    Print system login processes.

     -m    Only print information about the current terminal.  This is the POSIX way of saying who am i.

     -p    Print active processes spawned by init(8).

     -q    ``Quick mode'': List only the names and the number of users currently logged on.  When this option is used, all other options are
	   ignored.

     -r    Print the current runlevel.	Supported runlevels are:

	   d (DEATH)	    The system has halted.

	   s (SINGLE_USER)  The system is running in single user mode.

	   r (RUNCOM)	    The system is executing /etc/rc.

	   t (READ_TTYS)    The system is processing /etc/ttys.

	   m (MULTI_USER)   The system is running in multi-user mode.

	   T (CLEAN_TTYS)   The system is in the process of stopping processes associated with terminal devices.

	   c (CATATONIA)    The system is in the process of shutting down and will not create new processes.

     -s    List only the name, line and time fields.  This is the default.

     -T    Print a character after the user name indicating the state of the terminal line: '+' if the terminal is writable; '-' if it is not; and
	   '?' if a bad line is encountered.

     -t    Print last system clock change.

     -u    Print the idle time for each user, and the associated process ID.

     -v    When printing of more information is requested with -u, this switch can be used to also printed process termination signals, process
	   exit status, session id for windowing and the type of the entry, see documentation of ut_type in getutxent(3).

     am I  Returns the invoker's real user name.

     file  By default, who gathers information from the file /var/run/utmpx.  An alternative file may be specified which is usually /var/log/wtmpx
	   (or /var/log/wtmp, or /var/log/wtmpx.[0-6] or /var/log/wtmp.[0-6] depending on site policy as wtmpx can grow quite large and daily ver-
	   sions may or may not be kept around after compression by ac(8)).  The wtmpx and wtmp file contains a record of every login, logout,
	   crash, shutdown and date change since wtmpx and wtmp were last truncated or created.

     If /var/log/wtmpx or /var/log/wtmp are being used as the file, the user name may be empty or one of the special characters '|', '}' and '~'.
     Logouts produce an output line without any user name.  For more information on the special characters, see utmp(5).

FILES

     /var/run/utmp
     /var/run/utmpx
     /var/log/wtmp
     /var/log/wtmp.[0-6]
     /var/log/wtmpx
     /var/log/wtmpx.[0-6]

SEE ALSO

     last(1), mesg(1), users(1), getuid(2), utmp(5), utmpx(5)

STANDARDS

     The who utility is expected to conform to IEEE Std 1003.2-1992 (``POSIX.2'').

HISTORY

     A who utility appeared in Version 6 AT&T UNIX.

BSD
								 January 17, 2007							       BSD