How to find empty branches and tags in git

Question

I've migrated a big svn repository with hundreds of branches and tags, split them into multiple repositories and now i'm looking to check if there are any empty* branches/tags in these repositories that should be deleted before pushing the migration live.

Is there a faster way to find this than having to go to every repository and checkout every branch ?

---

*For the purpose of this question, "empty branch" or "empty tag" means a branch or tag that points to a commit that contains no files.

Answer 1

Run git ls-tree <branch/tag> | wc -l for every branch and tag using the programming language of you choice and check for 0. You get a list of branches with git branch and a list of tags with git tag.

Here is a simple example for branches using bash:

#!/bin/bash

for branch in $(git branch | cut -c 3-)
do
  if [ $(git ls-tree $branch | wc -m) -eq 0 ]
  then
    echo "branch $branch is empty"
  fi
done