It looks like you're logged in as "you" and you're trying to edit the system file /etc/fstab
; that file can only be written to by the super-user (root
). To edit that file, you must know the root password and you can temporarily become root with the su
utilities (both require the root password); e.g.,
Password: <type the root password>
# vi /etc/fstab
You exit su
) by typing Ctrl-D
at a command prompt.
If you do not know the root password, you will not be able to edit system files.
Whenever you attempt to edit a file that you do not own or a file that you do own but is read-only, the editor will want you to override with a "bang" (the exclamation point); in vi
or its derivatives, you would enter
Again, however, if you do not own or have write permission, that will fail.
Take a look at the manual pages for su
for more information.
Hope this helps some.