Script to delete branches that are stale and have no commits

cleanup.sh

#!/usr/bin/env bash

# Proceeds to go through remote branches and delete any branch that is over a year old and does not have a commit ahead of master

# Proceeds to output what it will delete
# ./cleanup.sh ../project-directory

# Proceeds to output and delete
# ./cleanup.sh ../project-directory --real-run

(
cd $1 || exit

RED='\033[0;31m'
NC='\033[0m' # No Color

NUMBER_OF_PRUNED_BRANCHES=0
NUMBER_OF_SKIPPED_BRANCHES=0
CURRENT_UNIX_TIMESTAMP=$(date +%s)
DEFAULT_BRANCH=$(git remote show origin | sed -n '/HEAD branch/s/.*: //p')

if [[ $2 = '--real-run' ]];
then
 echo "${RED}real run flag is activated, waiting 10 seconds before proceeding to delete${NC}"
 sleep 10
fi;

for branch in `git branch -r | grep -v HEAD`;
do
  # Although the default branch could be protected, and it could have recent commits, this might not be necessary
  # We skip it anyways just in case
  if [ "$branch" = "origin/${DEFAULT_BRANCH}" ];
  then
    echo "skipping default branch - $branch"
    continue
  fi


  COMMITS_DIFF_FROM_MASTER=$(git rev-list --left-right --count master...$branch | awk -F' ' '{print $2}')
  if [ "$COMMITS_DIFF_FROM_MASTER" = "0" ];
  then
    # we know the branch has no commits, therefore we can get the last commit (master) and check the date of that to get the age of the branch
    LAST_COMMIT_DATE=$(git log -1 --format=%ct $branch)
    NUMBER_OF_SECONDS_OLD_OF_BRANCH="$(($CURRENT_UNIX_TIMESTAMP-$LAST_COMMIT_DATE))"

    # 31536000 is one year
    if [[ $NUMBER_OF_SECONDS_OLD_OF_BRANCH -gt 31536000 ]];
    then
      echo "pruning $branch"

      if [[ $2 = '--real-run' ]];
      then
        git push origin --delete ${branch:7}
      fi;

      NUMBER_OF_PRUNED_BRANCHES=$((NUMBER_OF_PRUNED_BRANCHES+1))
    else
      echo "branch skipped - $branch"
      NUMBER_OF_SKIPPED_BRANCHES=$((NUMBER_OF_SKIPPED_BRANCHES+1))
    fi
  fi
done

echo "Number of pruned branches: $NUMBER_OF_PRUNED_BRANCHES"
echo "Number of skipped branches: $NUMBER_OF_SKIPPED_BRANCHES"
)