How to modify a specified commit?

Question

I usually submit a list of commits for review. If I have the following commits:

1. HEAD
2. Commit3
3. Commit2

Answer 1

Completely non-interactive command⁽¹⁾

I just thought I'd share an alias that I'm using for this. It's based on non-interactive interactive rebase. To add it to your git, run this command (explanation given below):

git config --global alias.amend-to '!f() { SHA=`git rev-parse "$1"`; git commit --fixup "$SHA" && GIT_SEQUENCE_EDITOR=true git rebase --interactive --autosquash "$SHA^"; }; f'

Or, a version that can also handle unstaged files (by stashing and then un-stashing them):

git config --global alias.amend-to '!f() { SHA=`git rev-parse "$1"`; git stash -k && git commit --fixup "$SHA" && GIT_SEQUENCE_EDITOR=true git rebase --interactive --autosquash "$SHA^" && git stash pop; }; f'

The biggest advantage of this command is the fact that it's no-vim.

---

⁽¹⁾given that there are no conflicts during rebase, of course

Usage

git amend-to  # e.g.
git amend-to HEAD~1
git amend-to aaaa1111

The name amend-to seems appropriate IMHO. Compare the flow with --amend:

git add . && git commit --amend --no-edit
# vs
git add . && git amend-to 

Explanation

• git config --global alias. '!' - creates a global git alias named that will execute non-git command
• f() { }; f - an "anonymous" bash function.
• SHA=`git rev-parse "$1"`; - converts the argument to git revision, and assigns the result to variable SHA
• git commit --fixup "$SHA" - fixup-commit for SHA. See git-commit docs
• GIT_SEQUENCE_EDITOR=true git rebase --interactive --autosquash "$SHA^"
  • git rebase --interactive "$SHA^" part has been covered by other answers.
  • --autosquash is what's used in conjunction with git commit --fixup, see git-rebase docs for more info
  • GIT_SEQUENCE_EDITOR=true is what makes the whole thing non-interactive. This hack I learned from this blog post.