Delete local branches that no longer exist on a remote

delete-orphaned-local-branches.sh

#!/bin/bash

set -e

# Delete all local branches whose remote branch no longer exists.
git branch -v | grep -E "[0-9a-zA-Z]{7} \[gone\]" | awk '{ print $1 }' | xargs git branch -D $1


# The commmand explained:
#
# List all branches. The -v flag will include "[gone]" in the output if the remote tracked branch no longer exists.
#   git branch -v 
# 
# Next filter rows that indicate their remote tracked branch no longer exists.
# The regex matches on the commit hash then the phrase "[gone]".
#   grep -E "[0-9a-zA-Z]{7} \[gone\]" 
# 
# For each matched row, pull the first column, which is the local branch name.
#   awk '{ print $1 }' 
# 
# Lastly, pass each branch name to the git branch delete command.
#   xargs git branch -D $1
#