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 mv
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
#
vi
filename
Move through the text with the arrow keys.
Esc (the escape key) puts vi
in command mode. Here are some commands:
x
delete letter the cursor is on
dd
delete the entire line (even if it wraps on the screen)
i
insert text at the cursor
a
insert 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
:w
to write your changes to disk and continue editing
:wq
to write and quit
:q!
to quit without saving changes
/text
to move the cursor to text
;
/
Enter (the enter key)
to find the next instance of
text
.
G
to go to the end of the file
n
G
to 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.
filename
vi
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
:r
.) 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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Questions that are not answered by the
documentation may be
sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.