This script allows to delete branches that were already merged and clean up your local setup

purge-merged-branches.sh

#!/bin/bash

# Switch to main branch
git checkout main
git pull

echo "Fetching latest changes from origin..."
git fetch -p

echo "=== Local branches that will be deleted ==="
git branch --merged | grep -v "\*" | grep -v main | grep -v master

echo ""
echo "=== Remote branches that will be deleted ==="
git branch -r --merged | grep -v 'origin/main' | grep -v 'origin/master' | grep origin | sed 's/origin\///'

read -p "Do you want to proceed with deletion? (y/n) " -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]
then
    # Delete local branches
    echo "Deleting local merged branches..."
    git branch --merged | grep -v "\*" | grep -v main | grep -v master | xargs git branch -d

    # Delete remote branches
    echo "Deleting remote merged branches..."
    git branch -r --merged | grep -v 'origin/main' | grep -v 'origin/master' | grep origin | sed 's/origin\///' | xargs -I{} git push origin --delete {}
else
    echo "Operation cancelled."
fi