Linux in a Nutshell, Fifth Edition

who | 511

Linux

Commands

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Copyright © 2006 O’Reilly & Associates, Inc. All rights reserved.

-v, -V, --version

Print version information and then exit.

--help

Print help information and then exit.

Example

$ which cc ls

/usr/bin/cc

ls: aliased to ls -sFC

who

who [options] [file]

who am i

Show who is logged into the system. With no options, list the

names of users currently logged in, their terminal, the time they

have been logged in, and the name of the host from which they

have logged in. An optional system file (default is /etc/utmp) can be

supplied to give additional information.

Options

-a, --all

Equivalent to -b -d --login -p -r -t -T -u.

am i

Print the username of the invoking user.

-b, --boot

Print time of last system boot.

-d, --dead

Print a list of dead processes.

--help

Print a help message and then exit.

-i, --idle

Include idle times. An idle time of

. indicates activity within

the last minute; one of old indicates no activity in more than a

day.

-l, --login

Print list of system login processes.

--lookup

Attempt to include canonical hostnames via DNS.

-m Same as who am i.

-p, --process

Print active processes spawned by init.

-q, --count

“Quick.” Display only the usernames and total number of

users.

-r, --runlevel

Print the current runlevel.

-s, --short

Print only name, line, and time. This is the default behaviour.