My situation was, I have a git repo converted from SVN to HG to GIT, and I wanted to extract just one source file. I also had weird characters like aÌ (an encoding mismatch corrupted Unicode ä) and spaces in the filenames.
Seems it's not particularly easy, and that's the reason I'll be answering my own question despite many similar questions regarding git [index-filter|subdirectory-filter|filter-tree], as I needed to use all the previous to achieve this!
So the question is: "How can I extract one file from a repository and place it at the root of the new repo?"
First a quick note, that even a spell like in a comment on Splitting a set of files within a git repo into their own repository, preserving relevant history
SPELL='git ls-tree -r --name-only --full-tree "$GIT_COMMIT" | grep -v "trie.lisp" | tr "n" " " | xargs -0 git rm --cached -r --ignore-unmatch' git filter-branch --prune-empty --index-filter "$SPELL" -- --all
will not help with files named like
aI<0300>$'302210' part once was a single letter:
So in order to extract a single file, in addition to filter-branch I also needed to do:
git filter-branch -f --subdirectory-filter lisp/source/model HEAD
Alternatively, you can use --tree-filter: (the test is needed, because the file was at another directory earlier, see: How can I move a directory in a Git repo for all commits?)
MV_FILTER='test -f source/model/trie.lisp && mv ./source/model/trie.lisp . || echo "Nothing to do."' git filter-branch --tree-filter $MV_FILTER HEAD --all
To see all the names a file have had, use:
git log --pretty=oneline --follow --name-only git-path/to/file | grep -v ' ' | sort -u
As described at http://whileimautomaton.net/2010/04/03012432
Also follow the steps on afterwards:
$ git reset --hard $ git gc --aggressive $ git prune $ git remote rm origin # Otherwise changes will be pushed to where the repo was cloned from