Line length marker in nano

Question

How can I highlight a given column using nano?

I'm using a fairly large terminal but I would like a mark to know if my code exceeds the limit of let's say 80 characters.

Answer 1

Command-line options:

nano -J 80 file
nano --guidestripe 80 file

Or add this to ~/.nanorc:

set guidestripe 80

That information is to be found in the manual under section 3. Notice that feature is absent for versions of nano older than 4.0.