Retaining Git history of subdirectory from parent repository

README.md

Subdirectory Git Repository

This is a mini howto on moving a subdirectory to its own repository retaining history

Howto

Assume PARENT is the original parent Git repository (locally) and CHILD is the new local repository that you wish to create from a subdirectory, retaining all of its history from the PARENT repository; PARENT_PATH and CHILD_PATH are the paths to PARENT and CHILD respectively; SUBDIR is the relative path within the repository under extraction:

1. git clone --no-hardlinks PARENT_PATH CHILD_PATH
2. pushd CHILD_PATH
3. git filter-branch --subdirectory-filter SUBDIR HEAD -- --all
4. git reset --hard
5. rm -rf .git/refs/original/
6. git reflog expire --expire=now --all
7. git gc --aggressive --prune=now
8. popd

Have fun and ENJOY! @SusanPotter

Heckle me in good spirits on Twitter ;) What Git hacks can you send my way? Cheers!

git-subdir-extract.sh

#!/usr/bin/env bash

PARENT_PATH=$1
CHILD_PATH=$2
SUBDIR=$3

git clone --no-hardlinks ${PARENT_PATH} ${CHILD_PATH}
pushd ${CHILD_PATH}
git filter-branch --subdirectory-filter SUBDIR HEAD -- --all
git reset --hard
rm -rf .git/refs/original/
git reflog expire --expire=now --all
git gc --aggressive --prune=now
popd

I'm not sure if I can issue a pull request on a gist. However, you might be interested that I fixed a defect in the script provided; the bare word SUBDIR is used where the variable ${SUBDIR} is required.