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who

summary

    This subchapter looks at who, a UNIX (and Linux) command.

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who

    This subchapter looks at who, a UNIX (and Linux) command.

    The who command was described in the first UNIX book, UNIX Programmer’s Manual, by Ken Thompson and Dennis Ritchie, published November 3, 1971.

list of who is using a system

    The who command will tell you all of the users who are currently logged into a computer. This is not particularly informative on a personal computer where you are the only person using the computer, but it can be useful on a server or a large computing system.

    Type who followed by the ENTER or RETURN key.

    $ who
    admin   console Aug 24 18:47
    admin   ttys000 Aug 24 20:09
    $

    The format is the login name of the user, followed by the user’s terminal port, followed by the month, day, and time of login.

which account is being used

    The command is who with the arguments am i will tell you which account you are currently using. This can be useful for a system administrator if the system administrator is using the su command and wants to be sure about which the system administrator is currently using.

    $ who am i
    admin    ttys000  Aug 25 17:30
    $

    A related command without any spaces, whoami, lets you know which account you are currently logged in with.

    $ whoami
    admin    ttys000  Aug 25 17:30
    $

other

    In June 2009, Ken Milberg named this command as one of the Top 50 universal UNIX commands at this web page Top 50 Universal INIX commands. Note that this web page requires agreeing to be spammed before you can read it.

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