Debugging is easier with line numbers. The default setting for vi and vim is for line numbers in the document to be hidden.
Setting Line Numbers within the Editor
You can turn on line numbers by typing
:set number
or
:set nu
The line numbers can also be turned off by typing
:set nonumber
or
:set nu!
Making Line Numbers Default in vi
You need to edit .vimrc or .bashrc (which is normally found in the root of the user’s folders). Add the following command:
set number
vi will start with line numbers every time a document is opened.
Jump to a Line When Opening vi
If you know which line you would like to edit in vi, you can go right to the line when you open the document in vi from the shell.
$ vi +linenumber file.php
i.e. vi +8 file.php will open the document and place the cursor in line 8.