#!/usr/bin/env bash

extract () {
  if [ -f "$1" ] ; then
    case "$1" in
      *.tar.bz2)   tar xvjf "$1"    ;;
      *.tar.gz)    tar xvzf "$1"    ;;
      *.bz2)       bunzip2 "$1"     ;;
      *.rar)       unrar x "$1"     ;;
      *.gz)        gunzip "$1"      ;;
      *.tar)       tar xvf "$1"     ;;
      *.tbz2)      tar xvjf "$1"    ;;
      *.tgz)       tar xvzf "$1"    ;;
      *.zip)       unzip "$1"       ;;
      *.Z)         uncompress "$1"  ;;
      *.7z)        7z x "$1"        ;;
      *.xz)        unxz "$1"        ;;
      *)           echo "don't know how to extract '$1'..." ;;
    esac
  else
    echo "'$1' is not a valid file!"
  fi
}

merkle-tree () {
  dirname="${1-.}"
  pushd "$dirname" > /dev/null || exit 1
  find . -type f              | \
    sort                      | \
    xargs -I{} sha256sum "{}" | \
    sha256sum                 | \
    awk '{print $1}'
  popd > /dev/null || exit 1
}