del_non_main_br.sh

# 1. nuke every *local* branch ≠ main
git branch | grep -vE '^\*? ?main$' | xargs -r git branch -D

# 2. tell your repo to forget any stale remote tracking refs
git fetch --prune origin

# 3. nuke every *remote* branch ≠ main
git branch -r | grep -vE 'origin/(HEAD|main)$' \
  | sed 's|origin/||' \
  | xargs -r -I{} git push origin --delete {}