Bash script to update all git repos inside a parent directory

update-all.bash

#!/bin/bash
PROJ_DIRS=(
  /path/to/parent/work/directory
  /path/to/another/parent/work/directory
)

update_git_repo () {
  cd $1;
  cd ..;
  echo "---";
  echo $PWD;
  export CURRENT_BRANCH="$(git symbolic-ref --short HEAD)"
  export MAIN_BRANCH="$(git remote show origin | grep 'HEAD branch' | cut -d' ' -f5)"
  git stash
  git checkout $MAIN_BRANCH;
  git fetch;
  git reset --hard $MAIN_BRANCH;
  # Delete all merged local branches to the main branch
  git branch --merged $MAIN_BRANCH | grep -v '^[ *]*master$' | grep -v '^[ *]*main$' | grep -v '^[ *]*staging$' | grep -v '^[ *]*dev$' | grep -v '^[ *]*develop$' | xargs git branch -D
  git pull
  git checkout $CURRENT_BRANCH
  git stash pop
}

for path in "${PROJ_DIRS[@]}"; do
  for dir in $(find $path -name .git -maxdepth 2 -type d); do
    update_git_repo $dir
  done
done