pipe all selections through the same shell command

[th1j5]

Feature

A method to pipe all selections to one shell command, instead of processing each selection separate.
Right now, maybe a statefull shell command could be used (although I wouldn't know how), but if #2634 would be merged, this sure isn't the case anymore.

Usecase

If e.g. wanting to copy/process a table, multiple selections are used.

If I use <a-|> xclip (also as seen in the wiki), then only the last line is stored in the clipboard buffer.

Second usecase can be found in #3331

Rationale

I don't think it's possible to really neatly solve this problem outside kakoune and thus that it should be provided by kakoune itself (right?)

Design considerations

• The separators (newline, null character, custom ;)
  In the far future maybe even a different separator depending on whether the selections continue on the same line or not (e.g. same line: tab, different line: newline)
• Command invocation (I would expect similar to | and <a-|>)
• My usecase is only reading (<a-|> i.e. ignoring output), but also when getting data back, how to handle this (e.g. just assume the same separators and the same lengthnumber of selections, then replace the selection with the output?)

Related

#3331

[mawww]

As you correctly identified, the hard part is to design the details of the feature

For example how to specify the separator ?

An option is tempting but is not easy to use interactively and prone to errors in scripting (as we then need to ensure the option in the current scope has the expected value while also ensuring we restore the value the user expect).

Passing it as the command parameter is tricky because Kakoune currently only supports numbers, and passing the codepoint in decimal is not a nice UI either. Maybe we could introduce non-digit parameters ? Arbitrary parameter count ? Now thats a new can of worm we are exploring...

I dont have any good answers for that, need a bit more brain cycles on the problem.

[Calum-J-I]

I don't really see how this can work. If you want pipe-to only then you can use

%sh{ echo $kak_selections }
%sh{ echo $kak_quoted_selections }

but if you want to maintain consistency with existing pipe commands then you need pipe also, which means mapping the output to your selections. You could assume one line of output == one selection but that doesn't make a lot of sense if your original selections are multiple lines. And the amount of output may not match the amount of input.

[th1j5]

I didn't look hard enough previously, but indeed for my usecase this method works.

I would argue however that pipe is also useful (as in usecase #3331)
Then the selection separator indeed cannot be part of the selections itself and there is a possibility that the amount of output differs from the amount of input.
In both those cases I would suggest just throwing an understandable error.

For later reference, this does the job for pipe-to my clipboard:
nop %sh{ echo $kak_selections | tr ' ' '\n' | xsel --clipboard --input}
remarks:

1. I should look into whitespace behaviour, I'm not sure if tr wouldn't change spaces to newlines when not intended by me
2. only xsel can be used easily, xclip doesn't close STDOUT, which looks like hanging.
   (https://askubuntu.com/a/898094, https://sourceforge.net/p/xclip/bugs/9/)