Mass remove local git branches and prune remote tracking

purge_branches.sh

// List all remotely tracked branches that do not exist in the remote repo
git remote prune origin --dry-run

// Prune all remotely tracked branches that do not exist in the remote repo
git remote prune origin

// List all local branches that were merged into master, explicitly exclude master from that list
git branch --merged master | grep -v 'master'

/*
    Delete local branches
    Each command does not delete master
 */

// Delete all local branches that were merged into master
git branch --merged master | grep -v 'master' | xargs git branch -d

// Safe deletion of all local branches (branches not merged into master will not get purged)
git branch | grep -v 'master' | xargs git branch -d

// Force delete of all local branches
git branch | grep -v 'master' | xargs git branch -D