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Let’s say I’m editing a file in vim, and I save (1). I continue editing, and I save again (2). Is it possible to “delete” this last save — meaning that vim would leave the file in its current state, but thinking the last save was 1?

To clarify, I open a file and write

one
two

I save it. Then I continue editing it, so it’s now

one
two
three
four

Now I need to save it in this state, and right after that do something (this is what I want to know) that will make vim still show me

one
two
three
four

but that if I close the file (or revert it with :e!, it’ll be at the state of

one
two

I want to do this because I use processing, and to use it with an external editor it relies on an external program that acts on the file, which means it needs to be saved, so the program can act upon the desired state of the file. Sometimes, however, I have a saved file and want to make a few changes just to test the result. However, if I don’t like the result, I’m “stuck” with this new saved version (unless I remember exactly how many times I would need to undo to get the previous saved state), and I’m looking for a way to chain this to the command that saves the file and runs the program against it.

user137369
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  • Can you explain why you want this? It seems like you are trying to do something convoluted. We might be able to explain a better alternative if we understood why you want this. – FDinoff Jun 30 '13 at 02:47
  • @FDinoff Yes, I’m aware it’s a weird request. I’ve updated the question with the reasons. I tried to make it clear. – user137369 Jun 30 '13 at 03:09

4 Answers4

2

This was taken from your original edit.

I have a vim action that needs the file to be saved before acting on it, but I still want to keep the experimentation possibility open (so if I don’t like the changes, I can just do :e! or close the file. Is it possible?

What you are looking for is called version control. Version control allows you to make changes to files, save and undo those changes. Take a look at git, or svn.

Heres an example of what you can do with git.

Lets say you have a file with contents 

one
two

Then you can check in your file into the version control software. (With git you do git commit)

Then later on you modify the file to be 

one
two
three
four

At this point you can do a git diff and see all the changes you did to the file since your last commit.

If you like the changes you can commit them. If you don't like the changes you can do a git checkout <file> and the file is reverted to its old state of

one
two
FDinoff
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  • I know of and use git, but what I want to do is so specific, going back and forth with the version control system would take longer and be more trouble than the current setup. I’m looking for an alternative to it. – user137369 Jun 30 '13 at 03:10
  • @user137369 what ever solution you come up with will end up being a form of version control. Might as well use one that already exists. – FDinoff Jun 30 '13 at 03:13
  • Somewhat agreed. However, copying the file back and forth would be less trouble, so it’s still not an optimal solution. I understand what I’m asking for might not be possible, but I’m looking for something that works like I’m intending, because I already know the alternatives. – user137369 Jun 30 '13 at 03:15
1

Here's a way to do it that builds on minitech's answer. Note that I haven't tested this extensively.

  1. Make your original edit and then save.
  2. Make your next edit and then save.
  3. Use :ea 1f to revert to the buffer's state at last save (see :h :earlier).
  4. Save again.
  5. Use :lat 1f to go back to the buffer as it looked after step 2 (see :h :later).
  6. Use :set nomodified so Vim doesn't think the buffer is modified and thus needs to be saved again.

The file on disk will still look like it did after step 1, because of the actions you took in step 3 and 4.

But I would also advise you to use version control instead. The fugitive plugin is a very nice way to use Git in Vim that doesn't get in your way.

echristopherson
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  • It’s very close to what I want — it seems to have some edge-cases I’d need to work around, but for the most part, it works. Thank you. – user137369 Jul 01 '13 at 22:20
  • I guess I misunderstood the requirements in the question; user137369 suggested an edit removing step #6, with a comment that they wanted Vim to still think the file was modified. If that's the case, just don't run `:set nomodified`. – echristopherson Jul 06 '13 at 04:45
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Your two descriptions seem to conflict with each other, so I’ll answer the second one :)

To mark the current file as unmodified, it’s:

:set modified!
Ry-
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  • It’s difficult to explain why I want to be able to do this, so I just deleted that part. The first one is what matters. – user137369 Jun 30 '13 at 02:05
  • @user137369: Okay, so save, undo, and then `set modified!`. – Ry- Jun 30 '13 at 02:05
  • That does not do it — it makes vim think the file was modified, but I really need it to be reverted to the last change, but still showing me the modifications I’ve made since then. – user137369 Jun 30 '13 at 02:10
  • @user137369: Open file, write “one two”. Save, add “three four”. `set modified!`. If you use `:e!`, it’s still “one two”, but “one two three four” is shown and the file isn’t modified to Vim. – Ry- Jun 30 '13 at 02:26
  • But I need to save it *after* “three four” *and then* mark it as unmodified, making vim think “one two” was the last save. – user137369 Jun 30 '13 at 02:37
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It sounds like you just want to:

  1. Undo a change
  2. Save the file

  3. Redo the change

    :undo | w | redo<CR>

d11wtq
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