[vim] Redefine tab as 4 spaces

My current setting assumes 8 spaces; how could I redefine it?

To define this on a permanent basis for the current user, create (or edit) the .vimrc file:

$ vim ~/.vimrc

Then, paste the configuration below into the file. Once vim is restarted, the tab settings will apply.

set tabstop=4       " The width of a TAB is set to 4.
                    " Still it is a \t. It is just that
                    " Vim will interpret it to be having
                    " a width of 4.

set shiftwidth=4    " Indents will have a width of 4

set softtabstop=4   " Sets the number of columns for a TAB

set expandtab       " Expand TABs to spaces

One more thing, use
:retab
to convert existing tab to spaces http://vim.wikia.com/wiki/Converting_tabs_to_spaces

My basic ~/.vimrc with comment:

set number " show line number                                                                                           
set tabstop=2 " set display width of tab; 1 tab = x space with                                                           
set expandtab " transform tab to x space (x is tabstop)                                                               
set autoindent " auto indent; new line with number of space at the beginning same as previous                                                                      
set shiftwidth=2 " number of space append to lines when type >> 

I copied and pasted this into my .vimrc file:

" size of a hard tabstop
set tabstop=4

" always uses spaces instead of tab characters
set expandtab

" size of an "indent"
set shiftwidth=4

The first 2 settings mean that when I press Tab I get 4 spaces. The third setting means that when I do V> (i.e. visual and indent) I also get 4 spaces.

Not as comprehensive as the accepted answer but it might help people who just want something to copy and paste.

There are few settings which define whether to use spaces or tabs.

So here are handy functions which can be defined in your ~/.vimrc file:

function! UseTabs()
  set tabstop=4     " Size of a hard tabstop (ts).
  set shiftwidth=4  " Size of an indentation (sw).
  set noexpandtab   " Always uses tabs instead of space characters (noet).
  set autoindent    " Copy indent from current line when starting a new line (ai).
endfunction

function! UseSpaces()
  set tabstop=2     " Size of a hard tabstop (ts).
  set shiftwidth=2  " Size of an indentation (sw).
  set expandtab     " Always uses spaces instead of tab characters (et).
  set softtabstop=0 " Number of spaces a <Tab> counts for. When 0, featuer is off (sts).
  set autoindent    " Copy indent from current line when starting a new line.
  set smarttab      " Inserts blanks on a <Tab> key (as per sw, ts and sts).
endfunction

Usage:

:call UseTabs()
:call UseSpaces()

To use it per file extensions, the following syntax can be used (added to .vimrc):

au! BufWrite,FileWritePre *.module,*.install call UseSpaces()

See also: Converting tabs to spaces.

Here is another snippet from Wikia which can be used to toggle between tabs and spaces:

" virtual tabstops using spaces
set shiftwidth=4
set softtabstop=4
set expandtab
" allow toggling between local and default mode
function TabToggle()
  if &expandtab
    set shiftwidth=8
    set softtabstop=0
    set noexpandtab
  else
    set shiftwidth=4
    set softtabstop=4
    set expandtab
  endif
endfunction
nmap <F9> mz:execute TabToggle()<CR>'z

It enables using 4 spaces for every tab and a mapping to F9 to toggle the settings.

or shorthand for vim modeline:

vim :set ts=4 sw=4 sts=4 et :

Add line
set ts=4
in
~/.vimrc file for per user
or
/etc/vimrc file for system wide

Permanent for all users (when you alone on server):

# echo "set tabstop=4" >> /etc/vim/vimrc

Appends the setting in the config file. Normally on new server apt-get purge nano mc and all other to save your time. Otherwise, you will redefine editor in git, crontab etc.

:set sw=4

See Mastering the VI editor

Make sure vartabstop is unset

set vartabstop=

Set tabstop to 4

set tabstop=4

Put your desired settings in the ~/.vimrc file -- See below for some guidelines and best practices.

There are four main ways to use tabs in Vim:

1. Always keep 'tabstop' at 8, set 'softtabstop' and 'shiftwidth' to 4 (or 3 or whatever you prefer) and use 'noexpandtab'. Then Vim will use a mix of tabs and spaces, but typing and will behave like a tab appears every 4 (or 3) characters.

   Note: Setting 'tabstop' to any other value than 8 can make your file appear wrong in many places (e.g., when printing it).

2. Set 'tabstop' and 'shiftwidth' to whatever you prefer and use 'expandtab'. This way you will always insert spaces. The formatting will never be messed up when 'tabstop' is changed.

3. Set 'tabstop' and 'shiftwidth' to whatever you prefer and use a |modeline| to set these values when editing the file again. Only works when using Vim to edit the file.

4. Always set 'tabstop' and 'shiftwidth' to the same value, and 'noexpandtab'. This should then work (for initial indents only) for any tabstop setting that people use. It might be nice to have tabs after the first non-blank inserted as spaces if you do this though. Otherwise aligned comments will be wrong when 'tabstop' ischanged.

Source:

• vimdoc.sourceforge.net/htmldoc/options.html#'tabstop'
• :help tabstop