Moving highlighted text to another file

Question

I have no idea how to do this, but here's my idea: Highlight some text in visual mode, type an ex command and a file name. It takes that highlighted text, deletes it, and appends it to the file you specify, creating it if it doesn't already exist.

I've italicized the parts I don't know how to do.

Answer 1

Combining the advice of @SunnyPun and @Rich, I came up with this:

command! -nargs=1 -range -complete=file Move '<,'>w! >> <args>|'<,'>d

Answer 2

Here is an extremely simplified version as a function (run it in Vim to test):

Hopefully Inspiring Function

Assuming that tee is working on your machine:

:function! PasteTo(path)
:  silent execute ":'<,'>w !tee -a ".a:path
:  normal! gvd
:endfunction

Then, select some text with linewise Visual mode, and do :call PasteTo('a.txt')

(You'll need to press <C-u> to clear that :'<,'> inserted)

The lines are gone and you can do :vnew a.txt to see them there. Try it to see if it also appends.

Explanation: First line appends the lines to the file. Second one deletes the lines. (By gv to repeat selection and d to use visual delete)

Making that an Ex Command

:command! -nargs=1 Cap call PasteTo(<q-args>)

Then, you can use :Cap a.txt (short form for cut and paste).

Questions

1. It is strange if I have forgotten to press <C-u>... like if I selected 2 lines the text will be pasted twice. And extra lines deleted? What happened?

   It runs for each selected line -- so when I selected 2, it copies and deletes once, and when the function is called for the 2nd line, it copies again and deletes again! You may want to do a mapping so <C-u> is pressed before you "enter" :Cap, or investigate for other ways to make your function works nicely with Visual mode.

2. Even if I just character-wise select, it copies the whole line.. How to get visually selected text in VimScript? (xolox is promising, I'm using his easytags plugin).

Hope this helps and hope I have given enough rope...