git remove all local branches not on remote code example
Example 1: delete local branches not on remote
git branch -vv | grep ': gone]'| grep -v "\*" | awk '{ print $1; }' | xargs -r git branch -DExample 2: Remove All Local Branches not on Remote
$ git branch -r | egrep -v -f /dev/fd/0 <(git branch -vv | grep origin) | xargs git branch -d