vi editor split one big line into multiple lines

You may need to insert a line break (newline) before or after each occurrence of a search pattern. That is useful if the newlines are needed, or as a temporary change to help understand some text. This tip shows how to insert newlines before or after specified strings, both manually and using a script to define a command so, for example, :%LineBreakAt would add a newline after and

tags in an HTML file. 

Using a script

The following script defines a user command to automate the insertion of line breaks. Save the script in a file called linebreakat.vim.

" Insert a newline after each specified string (or before if use '!').
" If no arguments, use previous search.
command! -bang -nargs=* -range LineBreakAt ,call LineBreakAt('', )
function! LineBreakAt(bang, ...) range
  let save_search = @/
  if empty(a:bang)
    let before = ''
    let after = '\ze.'
    let repl = '&\r'
  else
    let before = '.\zs'
    let after = ''
    let repl = '\r&'
  endif
  let pat_list = map(deepcopy(a:000), "escape(v:val, '/\\.*$^~[')")
  let find = empty(pat_list) ? @/ : join(pat_list, '\|')
  let find = before . '\%(' . find . '\)' . after
  " Example: 10,20s/\%(arg1\|arg2\|arg3\)\ze./&\r/ge
  execute a:firstline . ',' . a:lastline . 's/'. find . '/' . repl . '/ge'
  let @/ = save_search
endfunction 

In Vim, enter the command :so linebreakat.vim to source the script. 

If you want the script sourced 

automatically whenever Vim starts, place the file in directory 

~/.vim/plugin (Unix) or $HOME/vimfiles/plugin (Windows). On Windows, enter the 

following command to see the name of the required directory (which you may need to create):