Remove blank lines at end of file

Question

How can I augment/modify my trailing whitespace logic to also remove any empty or all whitespace lines at the end of a file?

My current whitespace stripping logic in my .vimrc is:

"remove trailing whitespaces automatically                                      
autocmd FileType c,cpp,java,python,markdown,shell autocmd BufWritePre <buffer> %s/\s\+$//e

I've tried Googling for an answer, but only get results that strip the end of the line, not that clean up at the end of the file.

Answer 1

The following substitution remove the last empty lines:

%s/\_s*\%$//e

The \_s atom match any white space including new line. The \%$ atom match the end of the buffer.

You could do:

autocmd FileType c,cpp,java,python,markdown,shell autocmd BufWritePre <buffer> %s/\s\+$//e|%s/\_s*\%$//e

Or combine both in one substitution:

autocmd FileType c,cpp,java,python,markdown,shell autocmd BufWritePre <buffer> %s/\(\s*$\|\_s\%$\)//e

To avoid that the cursor move to the end of the files when it contains some empty line you could combine it with mkview and loadview to restore the cursor and the scrolling position after the trimming:

autocmd FileType c,cpp,java,python,markdown,shell autocmd BufWritePre <buffer> mkview|%s/\(\s*$\|\_s\%$\)//e|loadview

Answer 2

Pretty straightforward solution with VimScript

autocmd BufWritePre <buffer> call deletebufline('%', prevnonblank('$') + 1, '$')

Answer 3

With some help from :help [range]:

:$;?\S?+,$delete

The range says from $;?\S?+ (roughly prevnonblank('$'), though with no special casing for the last line containing text) to $ (end of file), execute the deletion.

The address $;?\S?+ says to search backwards from the end of the file for non-whitespace and address the following line.

(This doesn't work for buffers with no trailing blank lines; instead it deletes content after the last row of blanks, even if there's text after that. For that, you probably want something more programmatic like Matt's answer.)