Redirect the output of a Vim or external command into a scratch buffer

redir.md

Redirect the output of a Vim or external command into a scratch buffer

Usage (any shell)

Show full output of command :hi in scratch window:

:Redir hi

Show full output of command :!ls -al in scratch window:

:Redir !ls -al 

Additional usage (depends on non-standard shell features so YMMV)

Evaluate current line with node and show full output in scratch window:

" current line
console.log(Math.random());

" Ex command
:.Redir !node

" scratch window
0.03987581000754448

Evaluate visual selection + positional parameters with bash and show full output in scratch window:

" content of buffer
echo ${1}
echo ${2}

" Ex command
:%Redir !bash -s foo bar

" scratch window
foo
bar

---

My Vim-related gists.

redir.vim

function! Redir(cmd, rng, start, end)
	for win in range(1, winnr('$'))
		if getwinvar(win, 'scratch')
			execute win . 'windo close'
		endif
	endfor
	if a:cmd =~ '^!'
		let cmd = a:cmd =~' %'
			\ ? matchstr(substitute(a:cmd, ' %', ' ' . shellescape(escape(expand('%:p'), '\')), ''), '^!\zs.*')
			\ : matchstr(a:cmd, '^!\zs.*')
		if a:rng == 0
			let output = systemlist(cmd)
		else
			let joined_lines = join(getline(a:start, a:end), '\n')
			let cleaned_lines = substitute(shellescape(joined_lines), "'\\\\''", "\\\\'", 'g')
			let output = systemlist(cmd . " <<< $" . cleaned_lines)
		endif
	else
		redir => output
		execute a:cmd
		redir END
		let output = split(output, "\n")
	endif
	vnew
	let w:scratch = 1
	setlocal buftype=nofile bufhidden=wipe nobuflisted noswapfile
	call setline(1, output)
endfunction

" This command definition includes -bar, so that it is possible to "chain" Vim commands.
" Side effect: double quotes can't be used in external commands
command! -nargs=1 -complete=command -bar -range Redir silent call Redir(<q-args>, <range>, <line1>, <line2>)

" This command definition doesn't include -bar, so that it is possible to use double quotes in external commands.
" Side effect: Vim commands can't be "chained".
command! -nargs=1 -complete=command -range Redir silent call Redir(<q-args>, <range>, <line1>, <line2>)

Thanks for your serious reply, now that I have a better understanding of these commands, I'm considering taking your methods to improve my config.

guys can you give me something in luascript?!

guys can you give me something in luascript?!

Thanks romainl for amazing work! I implement this command with lua script, with some extra commands to get repl-like features.

Also, this lua implementations support vertical and horizontal modifiers.

And note that this lua script doesn't use sh -c to do things, it spawns process directly, so no shell commands available but also no shell escaping needed.

My implementation in lua

Thanks, @Leenuus.

@gachikuku it looks like your wish came true.

Thank you @Leenuus! 🤗
@romainl it did.

Thank you @Leenuus! 🤗 @romainl it did.

Thanks, @Leenuus.

@gachikuku it looks like your wish came true.

Hi, @gachikuku , I rewrite my ugly codes and write a README like @romainl did.

And with vim.uv power, this implementation is totally async.

Split direction and stderr are handled too.

Can't thank @romainl more for such a simple, elegant, and powerful solution.

My gist here

You are very welcome, @Leenuus. Your gist seems almost plugin-ready.

You are very welcome, @Leenuus. Your gist seems almost plugin-ready.

Hope that I don't overengineer. 😂

@Leenuus @romainl is right!
That thing reserves a repo not a gist.
Plus it would be easier for folks to set it up, so make it a plugin.