To configure your system, you need to edit text files.  Most
      of them will be in the /etc directory; and
      you will need to su to root to be able to
      change them.  You can use the easy ee, but in
      the long run the text editor vi is worth
      learning.  There is an excellent tutorial on vi in
      /usr/src/contrib/nvi/docs/tutorial, if you
      have the system sources installed.
Before you edit a file, you should probably back it up.
      Suppose you want to edit /etc/rc.conf.  You
      could just use cd /etc to get to the
      /etc directory and do:
#cp rc.conf rc.conf.orig
This would copy rc.conf to
      rc.conf.orig, and you could later copy
      rc.conf.orig to
      rc.conf to recover the original.  But even
      better would be moving (renaming) and then copying back:
#mv rc.conf rc.conf.orig#cp rc.conf.orig rc.conf
because the mv command preserves the
      original date and owner of the file.  You can now edit
      rc.conf.  If you want the original back,
      you would then mv rc.conf rc.conf.myedit
      (assuming you want to preserve your edited version) and
      then
#mv rc.conf.orig rc.conf
to put things back the way they were.
To edit a file, type
#vifilename
Move through the text with the arrow keys.
      Esc (the escape key) puts vi
      in command mode.  Here are some commands:
xdelete letter the cursor is on
dddelete the entire line (even if it wraps on the screen)
iinsert text at the cursor
ainsert text after the cursor
Once you type i or a,
      you can enter text.  Esc puts you back in
      command mode where you can type
:wto write your changes to disk and continue editing
:wqto write and quit
:q!to quit without saving changes
/textto move the cursor to text;
	    /Enter (the enter key)
	    to find the next instance of
	    text.
Gto go to the end of the file
nGto go to line n in the
	    file, where n is a
	    number
to redraw the screen
go back and forward a screen, as they do with
	    more and view.
Practice with vi in your home directory
      by creating a new file with vi
       and adding and
      deleting text, saving the file, and calling it up again.
      filenamevi delivers some surprises because it is
      really quite complex, and sometimes you will inadvertently issue a
      command that will do something you do not expect.  (Some people
      actually like vi—it is more powerful
      than DOS EDIT—find out about the :r
      command.) Use Esc one or more times to be sure
      you are in command mode and proceed from there when it gives you
      trouble, save often with :w, and use
      :q! to get out and start over (from your last
      :w) when you need to.
Now you can cd to
      /etc, su to root, use
      vi to edit the file
      /etc/group, and add a user to wheel so the
      user has root privileges.  Just add a comma and the user's login
      name to the end of the first line in the file, press
      Esc, and use :wq to write
      the file to disk and quit.  Instantly effective.  (You did not
      put a space after the comma, did you?)
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    sent to <freebsd-questions@FreeBSD.org>.
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