git: forever remove files or folders from history

David Underhill — Wed, 01 Apr 2009 23:39:23 +0000

I recently had a need to rewrite a git repository’s history. This isn’t generally a very good idea, though it is useful if your repository contains files it should not (such as unneeded large binary files or copyrighted material). I also am using it because I had a branch where I only wanted to merge a subset of files back into master (though there are probably better ways of doing this). Anyway, it is not very hard to rewrite history thanks to the excellent git-filter-branch tool which comes with git. However, if your goal was to reduce a large repository’s size then git-filter-branch does not quite finish the job since it makes temporary backups of the filtered out files. To remove those, you need to do a little more work. To make it easier to permanently remove files, I wrapped it in a little bash script git-remove-history (also shown below) — simply go to the root of your repository and run the script with the list of files you want to delete and it will do the rest. There is an interesting thread about doing this here on KernelTrap.

#!/bin/bash
set -o errexit
 
# Author: David Underhill
# Script to permanently delete files/folders from your git repository.  To use 
# it, cd to your repository's root and then run the script with a list of paths
# you want to delete, e.g., git-delete-history path1 path2
 
if [ $# -eq 0 ]; then
    exit 0
fi
 
# make sure we're at the root of git repo
if [ ! -d .git ]; then
    echo "Error: must run this script from the root of a git repository"
    exit 1
fi
 
# remove all paths passed as arguments from the history of the repo
files=$@
git filter-branch --index-filter "git rm -rf --cached --ignore-unmatch $files" HEAD
 
# remove the temporary history git-filter-branch otherwise leaves behind for a long time
rm -rf .git/refs/original/ && git reflog expire --all &&  git gc --aggressive --prune

David Underhill » bash

git: forever remove files or folders from history