WHO(1) BSD General Commands Manual WHO(1)NAMEwho — display who is logged in
SYNOPSISwho [-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 versions 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 informa‐
tion 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 ALSOlast(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
