showing line numbers

Updated After the discussion of modes and installing packages, we can give some direct practical trick, courtesy of M-x all-things-emacs; note, I have updated this since, to work with Emacs 23.

Sometimes it is very useful to see the line numbers in a file – that is, on the left side of each line, the line number is shown. A use case for this is when showing something to a group of people. In that case, zooming and full-screen mode might also be useful.

The traditional way in emacs is to use setnu.el, but it's quite slow for big files. Fortunately, there is linum-mode; in your .emacs, add:

(autoload 'linum-mode "linum" "toggle line numbers on/off" t) 
(global-set-key (kbd "C-<f5>") 'linum-mode)    

Now, you can quickly show/hide linenumbers by pressing C-F5 (Control-F5).

You can also turn it on for specific modes; for example, to turn on line numbers when editing Perl code:

(add-hook 'perl-mode-hook
  (lambda() (linum-mode 1)))


Marc-André Lureau said...

Hi Djcb! welcome on panet emacsen :) Nice to read you there too.

Anonymous said...

I think the version of linum.el you linked to is pretty old. The home page has a much newer version.

SETH said...

You have some great and helpful posts here.


djcb said...

@Jason: thank -- updated the link.

Luizão said...

Another fix, instead of calling linum, it should be calling linum-mode.

djcb said...

@Luizão: 'linum' works for me at least...

Unknown said...

Cool blog, thanks for the info.

For me as well, the second linum needs to be linum-mode or the F6 shortcut doesn't work.

djcb said...

I have updated this post now, and it should all work for Emacs 23.