who(1)								       who(1)



NAME

  who - Identifies users currently logged in

SYNOPSIS

  who [-a] | [-AbdHlmMpqrstTu?hM] [file]

  who am I | who am i | whoami

  The who command displays information about users and processes on the local
  system.

FLAGS

  ?h  Prints a help message

  -a  Specifies all options; processes /var/adm/utmp or the named file with
      all flags on

  -Afile
      Displays accounting entries from the specified file. Accounting infor-
      mation is stored in the /var/adm/wtmp file, so you should specify that
      file. If you omit the file argument, the who command attempts to
      display information from the /var/adm/utmp file, which normally con-
      tains no accounting information. If accounting has never been enabled
      on your system, this option causes the who command to produce no out-
      put.

  -b  Indicates the most recent system start-up time and date.	The LC_TIME
      environment variable controls the format of the login time and date.

  -d  Displays all processes that have expired without being regenerated by
      init.  The exit_status field appears for dead processes and contains
      the termination and exit values (as returned by wait) of the dead
      processes.  (This flag is useful for determining why a process ended.)

  -h  Displays a help message.

  -H  Displays a header (title).

  -l  Lists only ttys not in use.  The user field is LOGIN in such cases.
      Other fields are the same as for user entries except that the state
      field does not appear.

  -m  Displays information about the current tty (same as who am i).

  -M  Lists only the user, line, time, and host (if not null) fields.

  -p  Lists any active process that is currently active and was previously
      generated by init.

  -q  Prints a quick listing of users and the number of users on the local
      system. When you use this option, all other options are ignored.

  -r  Indicates the current run-level of the system and provides information
      about the system's state. An example might be:
	       .   run-level 3 Jan 02 07:34   3	  0   S

      The date and time of the last state change.

      The 3 is the current state or run level (termination status).

      The 0 is the number of times the current state has been entered previ-
      ously (id).

      The S is an identification of the previous state or run level (exit
      status).

  -s  Lists only the user, line, and time fields.  (This is the default;
      thus, who and who -s are equivalent.) The LC_TIME environment variable
      controls the format of the time.

  -t  Indicates the last change to the system clock by the superuser using
      the date command.	 The LC_TIME environment variable controls the format
      of the time.

  -T  Displays the status of the tty line and indicates who can write to that
      tty as follows:

      +	  Writable by anyone.

      -	  Writable only by the superuser or the tty's owner.

      ?	  Bad line encountered.

  -u  Displays the username, terminal name, login time, line activity, and
      process-ID of each current user.	The LC_TIME environment variable con-
      trols the format of the login time.

DESCRIPTION

  The who command displays the following information for the users and/or
  processes you specify:

    +  Login name

    +  Terminal name

    +  Date

    +  Time of login

    +  Host

  Entering who am i or who am I displays your login name, terminal name, date
  and time you logged in, and host. Entering whoami displays your login name
  only.

  With flags, who can also display the elapsed time since line activity
  occurred, the process-ID of the command interpreter (shell), logins,
  logouts, restarts, and changes to the system clock, as well as other
  processes generated by the init process.

  The general output format of the who command is as follows:

       user [state] line time activity process_ID [exit_status]


  where:

    +  user is the user's login name.

    +  state indicates whether or not the line is readable by everyone (see
       the -T flag).

    +  line is the name of the line as found in the /dev directory.

    +  time is the time that user logged in.

    +  activity is the hours and minutes since activity last occurred on that
       user's line.  A . (dot) here indicates line activity within the last
       minute.	If the line has been quiet more than 24 hours or has not been
       used since the last system start-up, the entry is marked as old.

    +  process_ID is the process-ID of the user's shell.

    +  exit_status is the exit status of ended processes (see the -d flag).

  To obtain its information, who normally examines /var/adm/utmp.  If you
  specify another file, who examines the named file instead.  This file will
  usually be /var/adm/wtmp, which contains the history of all logins since
  the file was last created.

  Note that who only identifies users on the local node.

EXAMPLES

   1.  To display information about who is using the local system, enter:
	    who

       Information similar to the following is displayed:
	    george  console Jun 8  08:34  (abcpa.pasc.abc.c)


   2.  To display your username, enter:
	    who am i
       Information similar to the following is displayed:
	    huang   console Jun 8   08:34  (maguro)


   3.  To display a history of logins, logouts, system start-ups, and system
       shutdowns, enter:
	    who	 /var/adm/wtmp


       Information similar to the following is displayed:
	    huang   console Jun 8   08:34
	    john    console Jun 8   08:34
	    rachel  console Jun 8   08:22
	    spike   ttyp4   Jun 8   09:19


   4.  To display the run-level of the local system, enter:
	    who -r
       Information similar to the following is displayed:
	    run-level 3		     Jan 05 08:36     3	    0	  S

   5.  To display any active process that is currently active and was previ-
       ously generated by init, enter:
	    who -p


       Information similar to the following is displayed:
	    .	    tty4    Jun 8   04:15
	    .	    tty7    Jun 8   04:15
	    .	    tty14   Jun 8   04:15




FILES

  /var/adm/utmp
	     Contains user and accounting information.

  /var/adm/wtmp
	     Contains login history.

RELATED INFORMATION

  Commands:  date(1), init(8), login(1), mesg(1), su(1), users(1) whoami(1).

  Functions:  wait(2).

  Files:  utmp(4).