What's the best way to extract a tree from a git repository?

Question

Extracting a blob (file) from an arbitrary revision is easy with git show, e.g.:

 git show master:src/hello-world.c > /tmp/hello.c
         


        

Answer 1

You can use read-tree and checkout-index with a temporary index file:

GIT_INDEX_FILE=.tmp.index { git read-tree master:src &&
                            git checkout-index -a --prefix=dest/; 
                            rm -f .tmp.index; }

(Line breaks added for clarity, but it's really a one-liner.)

For a bare repository you have to pretend that a working tree exists and that you are in it:

GIT_INDEX_FILE=.tmp.index GIT_DIR=/path/to/repo.git GIT_WORK_TREE=. {
    git read-tree master:src &&
    git checkout-index -a --prefix=/path/to/dest/; 
    rm -f .tmp.index; }

If run from inside the bare repository you can omit setting GIT_DIR.