who(1)							      General Commands Manual							    who(1)

NAME

       who - Identifies users currently logged in

SYNOPSIS

       who [-a] | [-AbdhHlmMpqrstTu] [file]

       who am I

       who am i

       whoami

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

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       who:  XCU5.0

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

OPTIONS

       Specifies  all options; processes /var/adm/utmp or the named file with all options on.  Equivalent to using the -b, -d, -l, -p, -r, -t, -T,
       and -u options.	[Tru64 UNIX]  Displays accounting entries from the specified file.  Accounting information 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 contains no accounting information. If accounting has never been enabled on  your  system,  this  option
       causes  the  who  command to produce no output.	Indicates the most recent system start-up time and date.  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 option is useful for determining why a process ended.)  [Tru64 UNIX]  Displays a help
       message.  Displays a header (title).  Lists only terminals 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.  Displays information about the current terminal (same as who am i or
       who am I).  [Tru64 UNIX]  Lists only the user, line, time, and host (if not null) fields.  Lists  any  active  process  that  is  currently
       active  and  was  previously  generated by init.  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.  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

	      . is the user name for the corresponding process (init here).

	      Jan 02 07:34 is the time when the init process started.

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

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

	      The  S is an identification of the previous state or run level (exit status).  Lists only the user, line, and time fields.  (This is
	      the default; thus, who and who -s are equivalent.)  Indicates the last change to the system clock by the superuser  using  the  date
	      command.	 Displays  the	status	of  the terminal line and indicates who can write to that terminal as follows: Writable by anyone.
	      Writable only by the superuser or the terminal's owner.  [Tru64 UNIX]  Bad line encountered.  Displays the username, terminal  name,
	      login time, line activity, and process-ID of each current user.

OPERANDS

       Name of the file to be used instead of /var/adm/utmp to obtain information.

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. This is equivalent to the	-m
       option.

       [Tru64 UNIX]  Entering whoami displays your login name only.

       With  options,  who  also  can  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]

       user is the user's login name.  state indicates whether or not the line is readable by everyone (see the -T option).  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_sta-
       tus is the exit status of ended processes (see the -d option).

       [Tru64 UNIX]  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

       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 To display your username, enter: whoami

	      Information similar to the following is displayed: huang To display a history of logins, logouts, system start-ups, and system shut-
	      downs, 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 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 To display any active
	      process that is currently active and was previously 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

EXIT STATUS

       The following exit values are returned: Successful completion.  An error occurred.

ENVIRONMENT VARIABLES

       The  following  environment variables affect the execution of who: Provides a default value for the internationalization variables that are
       unset or null. If LANG is unset or null, the corresponding value from the default locale is used.  If any of the internationalization vari-
       ables  contain  an  invalid setting, the utility behaves as if none of the variables had been defined.  If set to a non-empty string value,
       overrides the values of all the other internationalization variables.  Determines the locale for the interpretation of sequences  of  bytes
       of  text data as characters (for example, single-byte as opposed to multibyte characters in arguments).	Determines the locale for the for-
       mat and contents of diagnostic messages written to standard error.  Determines the locale used for the format and contents of date and time
       strings in the output.  Determines the location of message catalogues for the processing of LC_MESSAGES.

FILES

       Contains user and accounting information.  Contains login history.

SEE ALSO

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

       Functions:  wait(2)

       Files:  utmp(4)

       Standards:  standards(5)

																	    who(1)