pkg-expand

#!/usr/bin/env zsh
# macos-scripts/pkg-expand

# pkg-expand
#  Expands a package serches for embeded packes and expands them
#  Searches for Bill of Material (Bom) files and reads them  

set -uo pipefail
# -u prevent using undefined variables
# -o pipefail force pipelines to fail on first non-zero status code

IFS=$'\n\t'
# Set Internal Field Separator to newlines and tabs
# This makes bash consider newlines and tabs as separating words
# See: http://redsymbol.net/articles/unofficial-bash-strict-mode/

function usage {

  echo -e "\\n Expands a package and any packages inside it"
  echo "  ./pkg-expand {.pkg}"
  
  exit 0
}


function pkg_search {

  while IFS=$'\n' read -r package; do 
    packages+=("${package}"); 
  done < <(find "${expand_dir}" -name "*.pkg" -type f)
}


function unpack {

  local embedded_pkg_name
  declare -i counter=0 

  for package in "${packages[@]}"; do
    embedded_pkg_name="$(basename "${package}" | awk -F '.pkg' '{print $1}')"
    if [[ "${embedded_pkg_name}" == "${pkg_name}" ]]; then
      embedded_pkg_name="${embedded_pkg_name}-${counter}"
      counter=+1
    fi
    pkgutil --expand-full "${package}" "${expand_dir}/${embedded_pkg_name}"
  done
}


function bom_search {
  while IFS=$'\n' read -r bom; do 
    boms+=("${bom}"); 
  done < <(find "${expand_dir}" -name "Bom" -type f)
}


function bom_read {
  local pkg_name

  for bom in "${boms[@]}"; do
    pkg_name=$(echo "${bom}" | awk -F '/' '{print $(NF-1)}' | tr -d '.pkg')
    lsbom "${bom}" > "${expand_dir}/${pkg_name}-Bom"
  done

}


function find_preinstall {
  while IFS=$'\n' read -r preinstall; do 
    preinstall_scripts+=("${preinstall}"); 
  done < <(find "${expand_dir}" -name 'preinstall' -type f)
}

function check_preinstall {

  for script in "${preinstall_scripts[@]}"; do
    echo "Checking ${script}"
    grep -ni "cp /tmp" "${script}"
    grep -ni "chmod 777 /Applications" "${script}"
    grep -ni "chown root:admin /Applications/" "${script}"
  done
}

function find_postinstall {
  while IFS=$'\n' read -r postinstall; do 
    postinstall_scripts+=("${postinstall}"); 
  done < <(find "${expand_dir}" -name 'postinstall' -type f)
}

function check_postinstall {

  for script in "${postinstall_scripts[@]}"; do
    echo "Checking ${script}"
    grep -ni "cp /tmp" "${script}"
    grep -ni "chmod 777 /Applications" "${script}"
    grep -ni "chown root:admin /Applications/" "${script}"
  done
}


function main {

  declare -a packages
  declare -a boms
  declare -a preinstall_scripts
  declare -a postinstall_scripts

  arg=${1:-"usage"}

  if [[ "${arg}" =~ ^(usage|help|-h|--help|🤷‍♂️|🤷‍♀️|"¯\_(ツ)_/¯")$ ]]; then
    usage
  fi

  pkg_name=$(basename "${arg}" | awk -F '.pkg' '{print $1}')
  readonly expand_dir="/tmp/${pkg_name}"
  mkdir "${expand_dir}"
  pkgutil --expand-full "${arg}" "${expand_dir}/${pkg_name}"
  
  pkg_search
  unpack
  bom_search
  bom_read

  find_preinstall
  find_postinstall
  check_preinstall
  check_postinstall
}

main "$@"