man(1) Manual page archive

     WHO(1)                                                     WHO(1)

          who, whois -  who is on the system

          who [-i] [ who-file ]

          who am i

          whois username

          Who, without an argument, lists the login name, terminal
          name, and login time for each current UNIX user.  With the
          -i option, the report includes the number of minutes that
          the user's terminal has been idle.

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

          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.

          Whois consults administrative files to identify the
          username. (Actually, whois uses grep(1) and can locate
          information by any useful key, such as real name or tele-
          phone number.)


          last(1), getuid(1), getuid(2), utmp(5), wtmp(5)