#!/usr/bin/env bash
# reset environment variables that could interfere with normal usage
unset GREP_OPTIONS
# put all utility functions here

# make a temporary file
git_extra_mktemp() {
    mktemp -t "$(basename "$0")".XXX
}

#
# check whether current directory is inside a git repository
#

is_git_repo() {
  git rev-parse --show-toplevel > /dev/null 2>&1
  result=$?
  if test $result != 0; then
    >&2 echo 'Not a git repo!'
    exit $result
  fi
}

is_git_repo
file="$1"
test -z "$file" && echo "file required." 1>&2 && exit 1
git filter-branch -f --index-filter "git rm -r --cached '$file' --ignore-unmatch" --prune-empty --tag-name-filter cat -- --all
