WHO(1) BSD General Commands Manual WHO(1)
NAME
who -- display who is logged in
SYNOPSIS
who [-abdHlmpqrsTtu] [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 -bdlprTtu.
-b Time of last system boot.
-d Print dead processes.
-H Write column headings above the regular output.
-l Print system login processes (unsupported).
-m Only print information about the current terminal. This is the POSIX way of saying who am i.
-p Print active processes spawned by launchd(8) (unsupported).
-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. This is meaningless on Mac OS X.
-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 (unsupported).
-u Print the idle time for each user, and the associated process ID.
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.
FILES
/var/run/utmpx
SEE ALSO
last(1), mesg(1), users(1), getuid(2), utmpx(5)
STANDARDS
The who utility conforms to IEEE Std 1003.1-2001 (``POSIX.1'').
HISTORY
A who utility appeared in Version 6 AT&T UNIX.
BSD
January 17, 2007 BSD