git diff-tree -r --no-commit-id --name-only --diff-filter=ACMRT $commit_id | xargs tar -rf export.tar
- -r $commit_id：Take a diff of the given commit to its parent(s) (including all subdirectories, not just the top directory)
- –no-commit-id –name-only：只输出文件名，不输出 SHA1
- –diff-filter=ACMRT：Only show files added, copied, modified, renamed or that had their type changed (eg. file → symlink) in this commit. This leaves out deleted files.