RE: visually mark off 80th column?

["Drew Adams" <drew.adams@oracle.com>]

> On Thu, Jan 21, 2010 at 5:53 PM, Drew Adams wrote:
> >> In my other editors I always turn on a little line that 
> >> delimits the 80th column. How do I do this in emacs?
> >
> > http://www.emacswiki.org/emacs/FindLongLines#ShowLongLines
> 
> I installed ColumnMarker from here:
> http://www.emacswiki.org/emacs/ColumnMarker
> into ~/emacs and then put this in my emacs file to always highlight
> the 80th column:
>
> (add-to-list 'load-path "~/emacs/")
> (require 'column-marker)
> (column-marker-1 80)
> 
> However this does nothing.

Hm. Works for me.

Do you actually have lines longer than 80 chars? ;-)
If not, try using (column-marker 30) as a test.

What happens if you do this interactively (in a buffer with long lines)?

M-: (column-marker-1 80)

> If I m-x column-marker-1 it simply highlights the current line...

That's the expected behavior.

If it works for you interactively like that, there's no reason it shouldn't also
work for you in your .emacs.

If it really doesn't work, try (a) loading column-marker.el (not *.elc), then
(b) `M-x debug-on-entry column-marker-1', and step through the execution using
`d', to see what happens.


BTW, if you want the highlighting only for certain modes, then use the mode hook
functions to turn it on there:

(add-hook 'foo-mode-hook
          (lambda ()
            (interactive)
            (column-marker-1 80)))