How can I safely undo changes that I may or may not have made?

Question

Too often do I make the mistake of typing with the wrong window focused (and have done so a few times with a USB authenticator). In programs with lots of hotkeys enabled (Gmail, VLC, Vim), this often has the unintended consequence of making unwanted modifications.

I can sometimes trace my steps and remember what I have typed to repair any changes or revert any settings that I tweaked if I catch myself early. Unfortunately, that is not always the case.

In Vim, I could have something as innocuous and apparent as altering a line of text which is easily undone. Or, I could have unknowingly modified something not so easily identified. If I accidentally type a sequence of unwanted commands in Vim, how can I check for and undo any edits or changes to settings?

Answer 1

Invoke

:undolist

to see when you made the last set of changes. If it says that there were a few changes made, e.g., "3 seconds ago," and you know that you only intentionally changed it, say, a minute ago, then execute

:earlier 10s

to revert to the desired state. Otherwise, if there are no recent changes, you don't have to do anything.

---

Further reference: :help undo-tree.

Answer 2

To rephrase the question, you are looking for a way to see or otherwise get notified about the changes you have made to a file, and then use an undo feature. There maybe other way or even plugins which supports this. But I'll explain what I've been using for the same purpose.

You combine existing vim feature to get this done. For example, you could define a function such as:

" Function: View changes after the last save
function! s:DiffSinceSave()
  let filetype=&ft
  diffthis
  vnew | r # | normal! 1Gdd
  diffthis
  exe "setlocal bt=nofile bh=wipe nobl noswf ro ft=" . filetype
  exe "normal! ]c"
endfunction
com! DiffSaved call s:DiffSinceSave()

You can then call it later and even map a shortcut key.

" Map key to function: View changes after the last save
nnoremap <leader>? :DiffSaved<CR>

This will open a split window based diff view which will show you changes made since the last save. After you have identified the changes made, then you can quit that view and use other vim features such as undo and undo tree, etc. or even plugins to revert back to previous states.

I realize that this is not ideal because you have to have a certain kind of workflow for this to be useful. But this works fairly well. And on the plus side, we aren't changing how vim works or relying on anything outside.

I hope you find this useful. I adapted this solution a while ago from snippets found on the Internet including vim Wikia. So that's where any credit is due.

Answer 3

It seems to me the simple answer to this is to press u until you undo a change you wanted to keep, then press Ctrl-R.

Answer 4

Like @superjer, I keep pressing u until the red [+] marker in my statusline disappears.

set statusline=%f\ %#Error#%m%##