When you start Vim, it will check the above six locations in that order for a vimrc file. The first found vimrc file will be used and the rest is ignored.
First Vim will look for a `$VIMINIT`. If there is nothing there, Vim will check for `$HOME/.vimrc`. If there is nothing there, Vim will check for `$HOME/.vim/vimrc`. If Vim finds it, it will stop looking and use `$HOME/.vim/vimrc`.
The first location, `$VIMINIT`, is an environment variable. By default it is undefined. If you want to use `~/dotfiles/testvimrc` as your `$VIMINIT` value, you can create an environment variable containing the path of that vimrc. After you run `export VIMINIT='let $MYVIMRC="$HOME/dotfiles/testvimrc" | source $MYVIMRC'`, Vim will now use `~/dotfiles/testvimrc` as your vimrc file.
The second location, `$HOME/.vimrc`, is the conventional path for many Vim users. `$HOME` in many cases is your home directory (`~`). If you have a `~/.vimrc` file, Vim will use this as your vimrc file.
The third, `$HOME/.vim/vimrc`, is located inside the `~/.vim` directory. You might have the `~/.vim` directory already for your plugins, custom scripts, or View files. Note that there is no dot in vimrc file name (`$HOME/.vim/.vimrc` won't work, but `$HOME/.vim/vimrc` will).
The fourth, `$EXINIT` works similar to `$VIMINIT`.
The sixth, `$VIMRUNTIME/defaults.vim` is the default vimrc that comes with your Vim build. In my case, I have Vim 8.2 installed using Homebrew, so my path is (`/usr/local/share/vim/vim82`). If Vim does not find any of the previous six vimrc files, it will use this file.
The answer is, "anything you want". The temptation to copy-paste other people's vimrc is real, but you should resist it. If you insist to use someone else's vimrc, make sure that you know what it does, why and how s/he uses it, and most importantly, if it is relevant to you. Just because someone uses it doesn't mean you'll use it too.
In the previous chapters, I have mentioned different plugins, like [fzf.vim](https://github.com/junegunn/fzf.vim), [vim-mundo](https://github.com/simnalamburt/vim-mundo), and [vim-fugitive](https://github.com/tpope/vim-fugitive).
Ten years ago, managing plugins was a nightmare. However, with the rise of modern plugin managers, installing plugins can now be done in seconds. I am currently using [vim-plug](https://github.com/junegunn/vim-plug) as my plugin manager, so I will use it in this section. The concept should be similar with other popular plugin managers. I would strongly recommend you to check out different ones, such as:
To add new plugins, drop your plugin names (`Plug 'github-username/repository-name'`) between the `call plug#begin()` and the `call plug#end()` lines. So if you want to install `emmet-vim` and `nerdtree`, put the following snippet down in your vimrc:
```
call plug#begin('~/.vim/plugged')
Plug 'mattn/emmet-vim'
Plug 'preservim/nerdtree'
call plug#end()
```
Save the changes, source it (`:source %`), and run `:PlugInstall` to install them.
In the future if you need to remove unused plugins, you just need to remove the plugin names from the `call` block, save and source, and run the `:PlugClean` command to remove it from your machine.
It is common to see a lot of `set` options in any vimrc. If you run the set command from the command-line mode, it is not permanent. You will lose it when you close Vim. For example, instead of running `:set relativenumber number` from the Command-line mode each time you run Vim, you could just put these inside vimrc:
You can also use a `let` instead of `set` (make sure to prepend it with `&`). With `let`, you can use an expression as a value. For example, to set the `'dictionary'` option to a path only if the path exists:
If you want to restrict the number of arguments, you can pass it `-nargs` flag. Use `-nargs=0` to pass no argument, `-nargs=1` to pass one argument, `-nargs=+` to pass at least one argument, `-nargs=*` to pass any number of arguments, and `-nargs=?` to pass 0 or one arguments. If you want to pass nth argument, use `-nargs=n` (where `n` is any integer).
`<args>` has two variants: `<f-args>` and `<q-args>`. The former is used to pass arguments to Vimscript functions. The latter is used to automatically convert user input to strings.
If you find yourself repeatedly performing the same complex task, it is a good indicator that you should create a mapping for that task.
For example, I have these two mappings in my vimrc:
```
nnoremap <silent><C-f> :GFiles<CR>
nnoremap <Leader>tn :call ToggleNumber()<CR>
```
On the first one, I map `Ctrl-F` to [fzf.vim](https://github.com/junegunn/fzf.vim) plugin's `:Gfiles` command (quickly search for Git files). On the second one, I map `<Leader>tn` to call a custom function `ToggleNumber` (toggles `norelativenumber` and `relativenumber` options). The `Ctrl-F` mapping overwrites Vim's native page scroll. Your mapping will overwrite Vim controls if they collide. Because I almost never used that feature, I decided that it is safe to overwrite it.
By the way, what is this "leader" key in `<Leader>tn`?
Vim has a leader key to help with mappings. For example, I mapped `<Leader>tn` to run the `ToggleNumber()` function. Without the leader key, I would be using `tn`, but Vim already has `t` (the "till" search navigation). With the leader key, I can now press the key assigned as a leader, then `tn` without interfering with existing commands. The leader key is a key that you can setup to start your mapping combo. By default Vim uses the backslash as the leader key (so `<Leader>tn` becomes "backslash-t-n").
I personally like to use `<Space>` as the leader key instead of the backslash default. To change your leader key, add this in your vimrc:
At minimum, you could have used `nmap` instead of `nnoremap` (`nmap <silent><C-f> :Gfiles<CR>`). However, it is a good practice to use the non-recursive variant to avoid potential infinite loop.
Here's what could happen if you don't map non-recursively. Suppose you want to add a mapping to `B` to add a semi-colon at the end of the line, then go back one WORD (recall that `B` n Vim is a normal-mode navigation key to go backward one WORD).
When you press `B`... oh no! Vim adds `;` uncontrollably (interrupt it with `Ctrl-C`). Why did that happen? Because in the mapping `A;<esc>B`, the `B` does not refer to Vim's native `B` function (go back one WORD), but it refers to the mapped function. What you have is actually this:
```
A;<esc>A;<esc>A;<esc>A;esc>...
```
To solve this problem, you need to add a non-recursive map:
```
nnoremap B A;<esc>B
```
Now try calling `B` again. This time it successfully adds a `;` at the end of the line and go back one WORD. The `B` in this mapping represents Vim's original `B` functionality.
The other map modes are: `map` (Normal, Visual, Select, and Operator-pending), `vmap` (Visual and Select), `smap` (Select), `xmap` (Visual), `omap` (Operator-pending), `map!` (Insert and Command-line), `lmap` (Insert, Command-line, Lang-arg), `cmap` (Command-line), and `tmap` (terminal-job). I won't cover them in detail. To learn more, check out `:h map.txt`.
You can split your vimrc to multiple files using Vim's `source` command. This command reads command-line commands from the given file argument.
Let's create a file inside the `~/.vim` directory and name it `/settings` (`~/.vim/settings`). The name itself is arbitrary and you can name it whatever you like.
With this setup, you easily know where to go. If you need to add more mappings, add them to the `/mappings.vim` file. In the future, you can always add more directories as your vimrc grows. For example, if you need to create a setting for your colorschemes, you can add a `~/.vim/settings/themes.vim`.
Vim can detect what kind of filetype the current buffer has (`:set filetype?`). If it is a `vim` filetype, you can use a marker fold method. Recall that a marker fold uses `{{{` and `}}}` to indicate the starting and ending folds.
Add `{{{` and `}}}` folds to the rest of your vimrc (don't forget to comment them with `"`):
Vimrc is an important component of Vim customization. A good way to start building your vimrc is by reading other people's vimrcs and gradually build it over time. The best vimrc is not the one that developer X uses, but the one that is tailored exactly to fit your thinking framework and editing style.
