who(1)

NAME
     who - print list of currently logged in users

SYNOPSIS
     who [file]

EXAMPLES

     who                 # Print user names, terminals and times

DESCRIPTION

     Who prints a list of currently logged in users.  For each one,  the  user
     name,  terminal,  and  login  time  is  printed.  This  program  gets its
     information from the file /etc/utmp, which is updated by init and  login.
     If the file does not exist, neither of these will create it, and who will
     not work.  Note that if you decide to create an  empty  /usr/adm/wtmp  to
     enable  the login accounting, it will grow forever and eventually fill up
     your disk unless you manually truncate it  from  time  to  time.   If  an
     optional file name is provided, the logins in that file will be printed.

SEE ALSO
     utmp(5).