WHO(1) OpenBSD Reference Manual WHO(1)NAME
who - display who is logged in
SYNOPSIS
who [-HmqTu] [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.
The options are as follows:
-H Write column headings above the regular output.
-m Only print information about the current terminal. This is the
POSIX way of saying who am i.
-q (Quick.) List only the names and the number of users currently
logged on. When this option is used, all other options are
ignored.
-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.
-u Print the idle time for each user.
am I Returns the invoker's real user name.
file By default, who gathers information from the file /var/run/utmp.
An alternate file may be specified which is usually /var/log/wtmp
(or /var/log/wtmp.[0-6] depending on site policy as wtmp can grow
quite large and daily versions may or may not be kept around
after compression by ac(8)). The wtmp file contains a record of
every login, logout, crash, shutdown and date change since wtmp
was last truncated or created.
If /var/log/wtmp is 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/log/wtmp
/var/log/wtmp.[0-6]
EXIT STATUS
The who utility exits 0 on success, and >0 if an error occurs.
SEE ALSOlast(1), mesg(1), users(1), w(1), getuid(2), utmp(5)STANDARDS
The who utility is compliant with the IEEE Std 1003.1-2008 (``POSIX'')
specification.
HISTORY
A who utility appeared in Version 3 AT&T UNIX.
OpenBSD 4.9 September 3, 2010 OpenBSD 4.9