How to do automatic code alignment for all the code or a block of code in vi/vim?

Question

I want to know what's the quickest way to do automatic code alignment in vi/vim or a method to add something in ~/.vimrc and then press a shortcut in vi/vim for making the code aligned/neat? Like I am using :set cindent in a .c code but it doesn't indent the code.

Answer 1

To enable automatic indenting — particularly for a C file — you can use something like this in your ~/.vimrc:

set cindent
set autoindent

For more on those options, run :help cindent and :help autoindent.

To indent existing code in a file, you can use =, which will indent a selection (or indeed a whole file). One way to indent all the code in an entire file is to run

gg=G

or

1G=G

either of which will jump to the top of the file (gg, or 1G), and then indent the code (=) from there to the end of the file (G). If you’d like to indent a particular block of code, you can visually select it and then run =; for example, to indent eight particular lines (including the one that the cursor is on), you could run

V7j=

which would enter linewise visual mode (V), selecting the current line, move down seven lines (7j), selecting those too, and then indent the selection (=).