anchor.diff:  
       v)  version="$OPTARG";;
       p)  prerelease="true";;
  +    n)  nightlies="true";;
       f)  cmdline_filename="$OPTARG";;
       P)  project="$OPTARG";;
       d)  cmdline_dl_dir="$OPTARG";;
  
positive.code: 
  case "$project" in
    "chef")
      metadata_url="<%= locals[:download_url] %>?v=${version}&prerelease=${prerelease}&p=${platform}&pv=${platform_version}&m=${machine}"
      ;;
    "server")
      metadata_url="<%= locals[:download_url] %>-server?v=${version}&prerelease=${prerelease}&p=${platform}&pv=${platform_version}&m=${machine}"
      ;;
    "chefdk")
      metadata_url="<%= locals[:download_url] %>-chefdk?v=${version}&prerelease=${prerelease}&p=${platform}&pv=${platform_version}&m=${machine}"
      ;;
      *)
  esac
  
negative.code: 
  prerelease="false"
  
  nightlies="false"
  
  project="chef"
  
  # Check whether a command exists - returns 0 if it does, 1 if it does not
  