mac vi 语法高亮

$ cat .vimrc
" Configuration file for vim
set modelines=0 " CVE-2007-2438
" Normally we use vim-extensions. If you want true vi-compatibility
" remove change the following statements
set nocompatible " Use Vim defaults instead of 100% vi compatibility
set backspace=2 " more powerful backspacing
syntax on
set nu!
set cindent
set ruler
" Don't write backup file if vim is being called by "crontab -e"
au BufWrite /private/tmp/crontab.* set nowritebackup nobackup
" Don't write backup file if vim is being called by "chpass"
au BufWrite /private/etc/pw.* set nowritebackup nobackup