Drop commits by commit message in `git rebase` - regex

Question

I would like to do a git rebase and drop commits whose commit messages match a certain regular expression. For example, it might work like
git rebase --drop="deletme|temporary" master
And this would do a rebase over master while dropping all commits containing the string deleteme or temporary.
Is is possible to do this with the standard Git tool? If not, is it possible with a third-party Git tool? In particular, I want it to be a single, noninteractive command.

Answer 1

This can be accomplished using the same method as I used in this answer.
First, we need to find the relevant commits. You can do that with something like:
git log --format=format:"%H %s" master..HEAD | grep -E "deleteme|temporary"
This will give you a list of commits with commit messages containing deleteme or temporary that are between master and your current branch. These are the commits that need to be dropped.
Save this bash script somewhere you can access it:
#!/bin/bash
for sha in $(git log --format=format:"%H %s" master..HEAD | grep -E "deleteme|temporary" | cut -d " " -f 1)
do
sha=${sha:0:7}
sed -i "s/pick $sha/drop $sha/" $#
done
Then run the rebase as:
GIT_SEQUENCE_EDITOR=/path/to/script.sh git rebase -i
This will automatically drop all commits that contain deleteme or temporary in their commit message.
As mentioned in my other answer:
[This script won't allow] you to customize what command is run to calculate which commits to use, but if this is an issue, you could probably pass in an environment variable to allow such customization.
Obligatory warning: Since a rebase rewrites history, this can be dangerous / disruptive for anyone else working on this branch. Be sure you clearly communicate what you have done with anyone you are collaborating with.

Answer 2

You could e. g. use interactive rebase. So do git rebase -i <first commit that should not be touched>, and then in vim where you have the list of commits, you can do :%s/^[^ ]* \([^ ]* issue\)/d \1/g to use drop stanza for all commits whose commit message starts with issue. But be aware that git rebase is not working optimally with merge commits. By default they are skipped and the history flattened, but you can try to keep them with parameters.

Answer 3

#Scott Weldon's answer works great for this usecase, however If the regex checks from the start of the message for example with (^(deleteme)|^(temporary)), then this won't work, since the start of the grep is the commit hash. So in that case you can use this instead
#!/bin/bash
for sha in $(git log --format=format:"%s %H" master..HEAD | grep -E "^(deleteme)|^(temporary)" | awk '{print $NF}')
do
sha=${sha:0:7}
sed -i "s/pick $sha/drop $sha/" $#
done
The core difference is that %sand %H swapped places, and therefore we search the last part of the string instead of the first part of the string by piping to awk '{print $NF}')
Also worth noting that this is called the same way as in Scott Weldon's answer:
GIT_SEQUENCE_EDITOR=/path/to/script.sh git rebase -i master