WHO(1) BSD General Commands Manual WHO(1)NAMEwho — display who is logged in
SYNOPSISwho [am I] [file]
The utility who 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.
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/run/wtmp
(or /var/run/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 out‐
put line without any user name. For more information on the special
characters, see utmp(5).
SEE ALSOlast(1), users(1), getuid(2), utmp(5)HISTORY
A who command appeared in Version 6 AT&T UNIX.
BSD December 30, 1993 BSD