Reverse Engineer a docker image for Dockerfile

#!/bin/bash

if [[ "$(docker images -q chenzj/dfimage:latest 2> /dev/null)" == "" ]]; then
  docker pull chenzj/dfimage
fi

read -e -p "Enter Image ID: " IMAGE_ID

if grep -q dfimage /etc/profile;
 then
 :
 else
  echo "" >> /etc/profile
  echo alias dfimage="'docker run -v /var/run/docker.sock:/var/run/docker.sock --rm chenzj/dfimage'" >> /etc/profile
  source /etc/profile
fi

docker run -v /var/run/docker.sock:/var/run/docker.sock --rm chenzj/dfimage $IMAGE_ID > Dockerfile1

docker history --no-trunc $IMAGE_ID  | tac | tr -s ' ' | cut -d " " -f 5- | sed 's,^/bin/sh -c #(nop) ,,g' | sed 's,^/bin/sh -c,RUN,g' | sed 's, && ,\n  & ,g' | sed 's,\s*[0-9]*[\.]*[0-9]*[kMG]*B\s*$,,g' | head -n -1 > Dockerfile2