Install neovim:
On Mac OS X: brew update brew install neovim
On linux: apt-get update apt-get install neovim
Use the following command to install nvim config file and plugin:
git clone https://github.com/VundleVim/Vundle.vim.git ~/.vim/bundle/Vundle.vim
git clone https://github.com/alvas/nvim.git ~/.config/nvim/
nvim +PluginInstall +qall
To index files in /usr/src and /usr/include folder for cscope:
$find /usr/src/ -type f ! -type l ( -iname *.h -o -iname *.c -o -iname *.cpp -o -iname *.cc -o -iname *.S ) > cscope.files
$find /usr/include -type f ! -type l ( -iname *.h -o -iname *.c -o -iname *.cpp ) >> cscope.files
$cscope -Rbqk