NAME
who  -  who is on the system

SYNOPSIS
who [ who-file ] [ am I ] [-r[nn]] [-tx] [-h]

DESCRIPTION
Who, without an argument, lists the name, typewriter channel, and
login time for each current UNIX user.

Without an argument, who examines the /etc/utmp  file  to  obtain
its  information.   If  a  file  is given, that file is examined.
Typically the given file will be /usr/adm/wtmp, which contains  a
record  of  all  the logins since it was created.  Then who lists
logins, logouts, and crashes since the creation of the wtmp file.
Each  login  is  listed  with  user  name,  typewriter name (with
'/dev/' suppressed), and date and  time.   When  an  argument  is
given,  logouts  produce a similar line without a user name.  Re-
boots produce a line with 'x' in the place of  the  device  name,
and a fossil time indicative of when the system went down.
If a -h argument is given, the history file is used for past logins.
If a -r argument is given,if an integer "nn" follows, the last "nn" 
lines in the history file are used.  If "nn" is missing, the default
is 192 lines.
If -the t atrgument is given, the character following it is the last
character of a terminal.  Who will show only the line for that tty.

With two arguments, who behaves as if it had no arguments  except
for  restricting  the  printout to the line for the current type-
writer.  Thus 'who am I' (and also 'who are you') tells  you  who
you are logged in as.

FILES
/etc/utmp

SEE ALSO
login (I), init (VIII)

BUGS
