Open quickfix/help in existing window [duplicate]

Question

my usual setup is two vertically split windows. Lets say my cursor is in left window. When I vimgrep something, I would like for quickfix window to reuse already opened right window and automatically open there as a new buffer. Similary, if cursor was in right window, quickfix should open in existing left window. Is that possible? This is what I currently have. But it will open third window that I will have to close later. Thanks.

augroup quickfix
    autocmd!
    autocmd QuickFixCmdPost [^l]* call OpenQuickFixList()
augroup END

"open in vertical split and realign windows
function OpenQuickFixList()
    vert cwindow
    execute "normal \<C-w>="
endfunction

Answer 1

if you want to always have it opened in vertical split with your current window, try next function:

augroup quickfix
    autocmd!
    autocmd QuickFixCmdPost [^l]* call OpenQuickFixList()
augroup END

function OpenQuickFixList()
    wincmd o
    vert cwindow
    wincmd p
    wincmd =
endfunction

What it does is

1. make current window the only one (:h wincmd)
2. vertically split cwindow
3. goes to previous window (remove this line if you want to stay in quickfix)
4. make windows equal

PS