Mass rename tags and push them with Git

example.sh

# variation of https://gist.github.com/knu/111055
# Rename tags named #.#.# or v#.#.# to v#.#.# and push the tag changes
git tag -l | while read t; do n="v${t#v}"; echo "$t - $n"; git tag $n $t; git push --tags ; git tag -d $t; git push origin :refs/tags/$t ; done