who(1) - NetBSD Manual Pages

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WHO(1)                  NetBSD General Commands Manual                  WHO(1)


NAME

     who -- display who is logged in


SYNOPSIS

     who [-abdHlmqrsTtuv] [file]
     who am i


DESCRIPTION

     The who utility displays a list of all users currently logged on, showing
     for each user the login name, tty name, the date and time of login, and
     hostname if not local.

     Available options:

     -a    Same as -bdlprTtuv.

     -b    Time of last system boot.

     -d    Print dead processes.

     -H    Write column headings above the regular output.

     -l    Print system login processes.

     -m    Only print information about the current terminal.  This is the
           POSIX way of saying who am i.

     -p    Print active processes spawned by init(8).

     -q    ``Quick mode'': List only the names and the number of users cur-
           rently logged on.  When this option is used, all other options are
           ignored.

     -r    Print the current runlevel.  Supported runlevels are:

           d (DEATH)        The system has halted.

           s (SINGLE_USER)  The system is running in single user mode.

           r (RUNCOM)       The system is executing /etc/rc.

           t (READ_TTYS)    The system is processing /etc/ttys.

           m (MULTI_USER)   The system is running in multi-user mode.

           T (CLEAN_TTYS)   The system is in the process of stopping processes
                            associated with terminal devices.

           c (CATATONIA)    The system is in the process of shutting down and
                            will not create new processes.

     -s    List only the name, line and time fields.  This is the default.

     -T    Print a character after the user name indicating the state of the
           terminal line: `+' if the terminal is writable; `-' if it is not;
           and `?' if a bad line is encountered.

     -t    Print last system clock change.

     -u    Print the idle time for each user, and the associated process ID.

     -v    When printing of more information is requested with -u, this switch
           can be used to also printed process termination signals, process
           exit status, session id for windowing and the type of the entry,
           see documentation of ut_type in getutxent(3).

     am I  Returns the invoker's real user name.

     file  By default, who gathers information from the file /var/run/utmpx.
           An alternative file may be specified which is usually
           /var/log/wtmpx (or /var/log/wtmp, or /var/log/wtmpx.[0-6] or
           /var/log/wtmp.[0-6] depending on site policy as wtmpx can grow
           quite large and daily versions may or may not be kept around after
           compression by ac(8)).  The wtmpx and wtmp file contains a record
           of every login, logout, crash, shutdown and date change since wtmpx
           and wtmp were last truncated or created.

     If /var/log/wtmpx or /var/log/wtmp are being used as the file, the user
     name may be empty or one of the special characters '|', '}' and '~'.
     Logouts produce an output line without any user name.  For more informa-
     tion on the special characters, see utmp(5).


FILES

     /var/run/utmp
     /var/run/utmpx
     /var/log/wtmp
     /var/log/wtmp.[0-6]
     /var/log/wtmpx
     /var/log/wtmpx.[0-6]


SEE ALSO

     last(1), mesg(1), users(1), getuid(2), utmp(5), utmpx(5)


STANDARDS

     The who utility is expected to conform to IEEE Std 1003.2-1992
     (``POSIX.2'').


HISTORY

     A who utility appeared in Version 1 AT&T UNIX:
           https://www.bell-labs.com/usr/dmr/www/man14.pdf

NetBSD 10.1                    September 1, 2019                   NetBSD 10.1