Content-type: text/html Man page of who

who

Section: User Commands (1)
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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:  XPG4, XPG4-UNIX

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. [Compaq]  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.) [Compaq]  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). [Compaq]  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
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 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. [Compaq]  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.

[Compaq]  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_status is the exit status of ended processes (see the -d option).

[Compaq]  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 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 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 variables 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 format 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)


 

Index

NAME
SYNOPSIS
STANDARDS
OPTIONS
OPERANDS
DESCRIPTION
EXAMPLES
EXIT STATUS
ENVIRONMENT VARIABLES
FILES
SEE ALSO

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Time: 02:42:48 GMT, October 02, 2010