Highlight lines longer than N characters in Vim

To highlight characters that go over a 90 column limit in Vim add the following to your .vimrc: highlight OverLength ctermbg=grey guibg=#EEEEEE
au BufWinEnter * let w:m1=matchadd('OverLength', printf('\%%>%dv.\+', 90), -1)

Sources

• http://stackoverflow.com/questions/235439/vim-80-column-layout-concerns/235962