WHO(1) OpenBSD Reference Manual WHO(1)
who - display who is logged in
who [-HmqTu] [file]
who am i
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 ig-
-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 af-
ter 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 out-
put line without any user name. For more information on the special
characters, see utmp(5).
last(1), mesg(1), users(1), w(1), getuid(2), utmp(5)
The who utility is expected to conform to IEEE Std 1003.2-1992
A who utility appeared in Version 3 AT&T UNIX.
OpenBSD 3.6 December 6, 1994 1