man(1) Manual page archive

     WHO(1)                                                     WHO(1)

          who  -  who is on the system

          who [ who-file ] [ am I ]

          Who, without an argument, lists the login name, terminal
          name, 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 cre-
          ated.  Then who lists logins, logouts, and crashes since the
          creation of the wtmp file.  Each login is listed with user
          name, terminal name (with `/dev/' suppressed), and date and
          time.  When an argument is given, logouts produce a similar
          line without a user name.  Reboots produce a line with `x'
          in the place of the device name, and a fossil time indica-
          tive of when the system went down.

          With two arguments, as in `who am I' (and also `who are
          you'), who tells who you are logged in as.


          getuid(2), utmp(5)