gitprune - delete local branches that aren't on origin

gitprune.sh

#! /bin/bash

#
# gitprune
#
# @author     trustin <https://stackoverflow.com/users/55808/trustin>
# @source     http://stackoverflow.com/a/22687460/1734964
# @license    unknown, but original code was posted publicly with the intention of being used by others
# @modified   Dan Bennett <http://ultrabenosaurus.ninja>
# 
# Changes:
#   Modified for use on Windows Git install.
#     -V flag of sort was unrecognised, so I removed it
#     mktemp executable doesn't exist, so I defined a temp directory and filenames
#     temp files were already cleaned up, added clean up of temp directory
#
# Installation:
#   For best results, place in your Git's bin directory and remove any file extension.
#
# Usage:
#   gitprune      list all branches that exist locally but not on origin, essentially a dry run
#   gitprune -D   delete all branches that exist locally but not on origin
#

if [[ "$1" == '-D' ]]; then
  DELETE=1
else
  DELETE=0
fi

mkdir -p ~/.gitprune/;
REMOTE_BRANCHES=~/.gitprune/.remotes;
( [ -e "$REMOTE_BRANCHES" ] || touch "$REMOTE_BRANCHES" );
LOCAL_BRANCHES=~/.gitprune/.locals;
( [ -e "$LOCAL_BRANCHES" ] || touch "$LOCAL_BRANCHES" );
DANGLING_BRANCHES=~/.gitprune/.dangling;
( [ -e "$DANGLING_BRANCHES" ] || touch "$DANGLING_BRANCHES" );

git for-each-ref --format="%(refname)" refs/remotes/origin/ | \
  sed 's#^refs/remotes/origin/##' > "$REMOTE_BRANCHES";
git for-each-ref --format="%(refname)" refs/heads/ | \
  sed 's#^refs/heads/##' > "$LOCAL_BRANCHES";
grep -vxF -f "$REMOTE_BRANCHES" "$LOCAL_BRANCHES" | \
  sort > "$DANGLING_BRANCHES";
rm -f "$REMOTE_BRANCHES" "$LOCAL_BRANCHES";

if [[ $DELETE -ne 0 ]]; then
  cat "$DANGLING_BRANCHES" | while read -r B; do
    git branch -D "$B";
  done;
else
  cat "$DANGLING_BRANCHES";
fi;
rm -f "$DANGLING_BRANCHES";

rmdir ~/.gitprune;