How do I run git rebase --interactive in non-interactive manner?

Question

Is it possible to do following?

1. Make git rebase --interactive to just output standard boilerplate to a file, instead to outputting to a file and opening it in editor.
2. Let the user edit the file.
3. Let user re-run git rebase with the name of edited file.
4. Go on with the usual rebase process.

Usecase: scripted rebasing of course. See how to re-order commits in Git non-interactively for example.

Answer 1

After some thinking and research, the answer turned out to be trivial: git rebase -i takes the editor name from the well-known EDITOR/VISUAL environment variables, so overriding that to point to a non-interactive script does the job.

However, EDITOR/VISUAL applies indifferently to the list of commits, commit messages when rewording and anything else. So, since http://git.kernel.org/?p=git/git.git;a=commit;h=821881d88d3012a64a52ece9a8c2571ca00c35cd , there's a special environment variable GIT_SEQUENCE_EDITOR which applies only to the commit list.

So, the recipe to re-order or flatten commits is:

Run: GIT_SEQUENCE_EDITOR=<script> git rebase -i <params>. Your <script> should accept a single argument: the path to the file containing the standard rebase commit list. It should rewrite it in-place and exit. Usual rebase processing happens after that.

Answer 2

Adding on to @pfalcon's answer, you can use sed as your GIT_SEQUENCE_EDITOR. For example, I wanted to edit each commit, so I did this:

GIT_SEQUENCE_EDITOR="sed -i -re 's/^pick /e /'" git rebase -i

Answer 3

The variable GIT_SEQUENCE_EDITOR was initially used to change the editor. It is possible to pass a script to this variable to use git rebase -i in a non-interactive manner. So it is possible to use:

GIT_SEQUENCE_EDITOR="sed -i -re 's/^pick 134567/e 1234567/'" git rebase -i 1234567^

This command will run sed on file provided by git rebase -i. It will change the line pick 134567 into e 1234567 (and so, edit the commit 1234567). You can change e with r (rework), f (fixup), s (squash) or d (drop) (the latter is not supported by old versions of git).

Based on that, I wrote a script that automatizes this task:

#!/bin/bash

ACTION=$1
COMMIT=$(git rev-parse --short $2)
[[ "$COMMIT" ]] || exit 1
CORRECT=
for A in p pick r reword e edit s squash f fixup d drop t split; do
     [[ $ACTION == $A ]] && CORRECT=1
done 
[[ "$CORRECT" ]] || exit 1
git merge-base --is-ancestor $COMMIT HEAD || exit 1
if [[ $ACTION == "drop" || $ACTION == "d" ]]; then
    GIT_SEQUENCE_EDITOR="sed -i -e '/^pick $COMMIT/d'" git rebase -i $COMMIT^^
elif [[ $ACTION == "split" || $ACTION == "t" ]]; then
    GIT_SEQUENCE_EDITOR="sed -i -e 's/^pick $COMMIT/edit $COMMIT/'" git rebase -i $COMMIT^^ || exit 1
    git reset --soft HEAD^
    echo "Hints:"
    echo "  Select files to be commited using 'git reset', 'git add' or 'git add -p'"
    echo "  Commit using 'git commit -c $COMMIT'"
    echo "  Finish with 'git rebase --continue'"
else
    GIT_SEQUENCE_EDITOR="sed -i -e 's/^pick $COMMIT/$1 $COMMIT/'" git rebase -i $COMMIT^^
fi

The first argument should be one action. The script uses the same action names than git-rebase. It also add 'split' action (and allow to use drop with old versions of git).

It also checks that commit you ask for is an ancestor of HEAD. It a common (and really annoying) mistake with rebase -i.

The second argument is the commit to want to edit/delete/split/reword.

Then you add an alias to your .gitconfig:

[alias]
  autorebase = ! path_to_your_script

Answer 4

Expanding on pfalcon's answer:

Run GIT_SEQUENCE_EDITOR=<script> git rebase -i <params>. <script> should accept single argument - path to file containing standard rebase commit list. The script should rewrite it in-place and exit. Usual rebase processing happens after that.

If you have an environment variable that contains the contents you want:

GIT_SEQUENCE_EDITOR='echo "$REBASE_DATA" >' git rebase -i [<additional params>]

Catting a file would work too:

GIT_SEQUENCE_EDITOR='cat rebase_data_file >' git rebase -i [<additional params>]

Answer 5

You can use touch as the editor which will touch the file so it will appear modified. For example

GIT_SEQUENCE_EDITOR=touch git rebase -i [commit]

To alias it, given baseline as a tag I want to rebase against

git config alias.baseline '!GIT_SEQUENCE_EDITOR=touch git rebase -i baseline'

The alias works under Windows because the shell it is executing is bash not cmd.

Answer 6

interactive modes brings up the set editor to work with.
the editor in use can be retrieved with:

git config --get core.editor

So, if you set a non-interactive editor - that is an editor that accepts commands on stdin, you can work with --interactive in a non-interactive way :)
I know for sure vim accepts commands, and so does the standard editor ed, ofcourse.

so, hold the interactive editor (if wanted)

$ ied="$(git config --get core.editor)"

set the non-interactive editor

$ git config --unset-all core.editor
$ git config --add core.editor ed

and do work with it..

$ printf '%s\n' "some-ed-cmd" "another-ed-cmd" "wq" | git rebase -i HEAD~5

and restore the editor (if wanted)

$ git config --unset-all core.editor
$ git config --add core.editor "$ied"

Answer 7

I found the solution. You can use:

$ GIT_SEQUENCE_EDITOR=true git rebase -i --autosquash $COMMIT_HASH~1

Answer 8

As others have mentioned, you need to provide a custom GIT_SEQUENCE_EDITOR value that will modify the interactive rebase file. If you just want to perform an action on a single commit, you can do it as follows:

# Runs "edit" on HEAD~3
GIT_SEQUENCE_EDITOR="sed -i -ze 's/^pick/edit/'" git rebase -i HEAD~3

Alternatively, here's a function to generalize this:

# Usage: git-rebase-custom edit HEAD~3
git-rebase-custom() {
    local action=$1
    shift

    GIT_SEQUENCE_EDITOR="sed -i -ze 's/^pick/$action/'" git rebase -i "$@"
}

Answer 9

Based on Jezz's answer, I made a shell-agnostic script (GitReb) which works with multiple-argument revisions, :/<text> syntax, root commit and also does some sanity checks.

I also made it simpler and removed the t/split action and delete->drop conversion which IMO are out of this script's scope.