My vimrc. A hybrid to work on both Linux and MacOS.

.vimrc

" Some plugins, colors and other things are expected.
" Check another time for complete instructions

" Set 'nocompatible' to ward off unexpected things that your distro might
" have made, as well as sanely reset options when re-sourcing .vimrc
set nocompatible

" Attempt to determine the type of a file based on its name and possibly its
" contents. Use this to allow intelligent auto-indenting for each filetype,
" and for plugins that are filetype specific.
filetype indent plugin on

" Enable syntax highlighting
syntax on

" allows you to re-use the same
" window and switch from an unsaved buffer without saving it first. Also allows
" you to keep an undo history for multiple files when re-using the same window
" in this way. Note that using persistent undo also lets you undo in multiple
" files even in the same window, but is less efficient and is actually designed
" for keeping undo history after closing Vim entirely. Vim will complain if you
" try to quit without saving, and swap files will keep you safe if your computer
" crashes.
set hidden

" Better command-line completion
set wildmenu

" Show partial commands in the last line of the screen
set showcmd

" Highlight searches (use <C-L> to temporarily turn off highlighting; see the
" mapping of <C-L> below)
set hlsearch

" Modelines have historically been a source of security vulnerabilities. As
" such, it may be a good idea to disable them and use the securemodelines
" script, <http://www.vim.org/scripts/script.php?script_id=1876>.
set nomodeline

" Use case insensitive search, except when using capital letters
set ignorecase
set smartcase

" Allow backspacing over autoindent, line breaks and start of insert action
set backspace=indent,eol,start
 
" When opening a new line and no filetype-specific indenting is enabled, keep
" the same indent as the line you're currently on. Useful for READMEs, etc.
set autoindent
 
" Stop certain movements from always going to the first character of a line.
" While this behaviour deviates from that of Vi, it does what most users
" coming from other editors would expect.
set nostartofline
 
" Display the cursor position on the last line of the screen or in the status
" line of a window
set ruler
 
" Always display the status line, even if only one window is displayed
set laststatus=2
 
" Instead of failing a command because of unsaved changes, instead raise a
" dialogue asking if you wish to save changed files.
set confirm
 
" Use visual bell instead of beeping when doing something wrong
set visualbell
 
" And reset the terminal code for the visual bell. If visualbell is set, and
" this line is also included, vim will neither flash nor beep. If visualbell
" is unset, this does nothing.
set t_vb=
 
" Enable use of the mouse for all modes
" set mouse=a
 
" Set the command window height to 2 lines, to avoid many cases of having to
" "press <Enter> to continue"
set cmdheight=2
 
" Display line numbers on the left
set number
 
" Quickly time out on keycodes, but never time out on mappings
set notimeout ttimeout ttimeoutlen=200
 
" Use <F11> to toggle between 'paste' and 'nopaste'
set pastetoggle=<F11>

" Indentation settings for using 4 spaces instead of tabs.
" Do not change 'tabstop' from its default value of 8 with this setup.
set shiftwidth=4
set softtabstop=4
set expandtab

" Map Y to act like D and C, i.e. to yank until EOL, rather than act as yy,
" which is the default
map Y y$
 
" Map <C-L> (redraw screen) to also turn off search highlighting until the
" next search
nnoremap <C-L> :nohl<CR><C-L>

" Make vim nice on black modern terminals
set t_Co=256
set background=dark

" Powerline status
python3 from powerline.vim import setup as powerline_setup
python3 powerline_setup()
python3 del powerline_setup

" Coloring
colorscheme gruvbox

" NERDTree on opening a folder
autocmd StdinReadPre * let s:std_in=1
autocmd VimEnter * if argc() == 1 && isdirectory(argv()[0]) && !exists("s:std_in") | exe 'NERDTree' argv()[0] | wincmd p | ene | exe 'cd '.argv()[0] | endif

" If more than one window and previous buffer was NERDTree, go back to it.
autocmd BufEnter * if bufname('#') =~# "^NERD_tree_" && winnr('$') > 1 | b# | endif

" Close Vim when last opened file is closed, so it won't remain with NERDTree
" buffer opened
autocmd BufEnter * if (winnr("$") == 1 && exists("b:NERDTree") && b:NERDTree.isTabTree()) | q | endif