Generate a SHA256 checksum map of a directory and allow to compare it with another directory

csmap.bash

#!/bin/bash
version="1.0.0"

print_help() {
  echo "Usage: csmap [dir]"
  echo ""
  echo "This command generated a \"csmap.txt\" file containing a SHA256 checksum of"
  echo "each file of a directory recursively. If a \"csmap.txt\" file exists,"
  echo "it generates a temporary \"csmap.compare.txt\" file, do the mapping and"
  echo "compare it with the \"csmap.txt\" file."
}

if [ -z "$1" ];then
  echo "Error: [dir] has to be specified"
  echo ""
  print_help
  exit 1
fi

if [ "$1" == "-v" -o "$1" == "--version" ];then
  echo $version
  exit 0
fi

if [ "$1" == "-h" -o "$1" == "--help" ];then
  print_help
  exit 0
fi

if [ ! -d "$1" ];then
  echo "Error: Invalid [dir]"
  echo ""
  print_help
  exit 1
else
  directory=$(dirname "$1")
fi

recurse() {
  for i in "$1"/*;do
    if [ -d "$i" ];then
      recurse "$i"
    elif [ -f "$i" ]; then
      shasum -a 256 "$i" >> "$map_file"
    fi
  done
}

if [ -f "$directory/csmap.txt" ];then
  compare_at_the_end=true
  if [ -f "$directory/csmap.compare.txt" ];then
    rm "$directory/csmap.compare.txt"
  fi
  map_file="$directory/csmap.compare.txt"
else
  compare_at_the_end=false
  map_file="$directory/csmap.txt"
fi

recurse $directory

if [ "$compare_at_the_end" = true ];then
  echo "Compare Maps: if there's diffs, they'll appear here..."
  # Ignore the "csmap.txt" of the "csmap.compare.txt" file that wasn't in the "csmap.txt" file.
  cat "$directory/csmap.compare.txt" | sed '/csmap.txt/d' | diff "$directory/csmap.txt" -
  rm "$directory/csmap.compare.txt"
else
  echo "Map generated"
fi