List Heroku buildpacks for each app using the Heroku CLI.

list-heroku-buildpacks.sh

#! /bin/bash

app_list=$(heroku apps -A -t=${@} | grep -v '^===')
for app in $app_list; do
  buildpacks=$(heroku buildpacks -a $app | grep -v '^===' | sed -E 's/[0-9]+\. //')

  if [[ $buildpacks =~ "has no Buildpack URL set" ]]; then
    echo $app "has no buildpacks"
  else 
    for buildpack in $buildpacks; do
      echo $app ">>" $buildpack
    done
  fi
done