.vimrc Example

set encoding=utf8
set guifont=DroidSansMono\ Nerd\ Font\ 11

call plug#begin()
Plug 'preservim/nerdtree'
Plug 'ryanoasis/vim-devicons'
call plug#end()

" Start NERDTree when Vim starts with a directory argument.
autocmd StdinReadPre * let s:std_in=1
autocmd VimEnter * if argc() == 1 && isdirectory(argv()[0]) && !exists('s:std_in') |
    \ execute 'NERDTree' argv()[0] | wincmd p | enew | execute 'cd '.argv()[0] | endif

let g:NERDTreeFileLines = 1

" Mirror the NERDTree before showing it. This makes it the same on all tabs.
nnoremap <C-n> :NERDTreeMirror<CR>:NERDTreeFocus<CR>

" If another buffer tries to replace NERDTree, put it in the other window, and bring back NERDTree.
autocmd BufEnter * if winnr() == winnr('h') && bufname('#') =~ 'NERD_tree_\d\+' && bufname('%') !~ 'NERD_tree_\d\+' && winnr('$') > 1 |
    \ let buf=bufnr() | buffer# | execute "normal! \<C-W>w" | execute 'buffer'.buf | endif

" Function to open the file or NERDTree or netrw.
"   Returns: 1 if either file explorer was opened; otherwise, 0.
function! s:OpenFileOrExplorer(...)
    if a:0 == 0 || a:1 == ''
        NERDTree
    elseif filereadable(a:1)
        execute 'edit '.a:1
        return 0
    elseif a:1 =~? '^\(scp\|ftp\)://' " Add other protocols as needed.
        execute 'Vexplore '.a:1
    elseif isdirectory(a:1)
        execute 'NERDTree '.a:1
    endif
    return 1
endfunction