Vim: make text go red or screen flash after 80 column mark?

Question

Is there a way to make Vim warn me after a line has exceeded n characters?

Something simple like a screen flash or the text go bold red or something.

!! Bonus points if n can be made a variable that is easy to set in each individual window (I use 80 columns usually, but 100 columns for PHP).

Answer 1

There are two possible solutions:

1. If your version of Vim is at least 7.3, just set 'colorcolumn' option (see :help 'colorcolumn'), e.g. to 81:

   set colorcolumn=81
   

   It can also highlight more than one column:

   let &colorcolumn = join(range(81, 400), ',')
   

2. If you have Vim version prior to 7.3, you may want to define custom highlighting rule to highlight all characters after specific column, e.g.:

   syn match tooLong /\%81c.*$/
   hi link tooLong Error
   

To have different settings for different file types, put this commands into appropriate filetype plugin (for example to ~/.vim/ftplugin/cpp.vim). Or define autocommands (see :help :autocmd) triggered by FileType event (see :help FileType) in your .vimrc.