How to reformat "gq"ed text in one line per paragraph format in Vim

Question

I have some text files previously formatted in vim using "gggqG". Now I need to convert them to one line per paragraph format. I saw a way(using :g command) to do that before, but I have forgot it. Anyone knows?

Answer 1

There are two approaches I know of:

• Set textwidth to something big and reformat:

  :set tw=1000000
  gggqG
  

• Use substitute (this is more appropriate if you want to do it in a mapping):

  :%s/.\zs\n\ze./ /
  

Explanation of the latter:

:%s        " Search and replace across the whole file
/          " Delimiter
.\zs\n\ze. " Look for a character either side of a new-line (so ignore blank lines).
           " The \zs and \ze make the replacement only replace the new-line character.
/ /        " Delimiters and replace the new-line with a space.

Answer 2

If your text paragraphs are separated by a blank line, this seems to work:

:g!/^\s*$/normal vipJ

:g global (multi-repeat)

!/^\s*$/ match all lines except blank lines and those containing only whitespace.

normal enters 'normal' mode

vip visually select inner paragraph

J join lines