Getting Help

man

Most UNIX systems come with on-line manuals that you can access to get help while working on the system. The man command enables you to get help on UNIX commands you specify. man is derived from the word "manual", as in "on-line manual pages".

$
$ man who

who(1)                  who(1)

NAME
  who - who is on the system

SYNOPSIS
  who [-uTlHpdbrtas] [file]
  who -q [-n x] [file]
  who am i

DESCRIPTION
  who can list the user's name, terminal line, login time,
  elapsed time since activity occurred on the line, and the
  process ID of the command interpreter (shell) for each ...

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