anchor.diff:  # @return 0 if omnibus needs to be installed, non-zero otherwise
   should_update_chef() {
     if test ! -d "$1" ; then return 0
  +  elif test ! -f "$1/bin/chef-client" ; then return 0
     elif test "$2" = "true" ; then return 1
     elif test "$2" = "latest" ; then return 0
     fi
  
positive.code: # do_curl URL FILENAME
  do_curl() {
    echo "trying curl..."
    curl -sL <%= "--proxy \"#{knife_config[:bootstrap_proxy]}\" " if knife_config[:bootstrap_proxy] %> <%= knife_config[:bootstrap_curl_options] %> -D $tmp_dir/stderr "$1" > "$2"
    rc=$?
    # check for 404
    grep "404 Not Found" $tmp_dir/stderr 2>&1 >/dev/null
  
negative.code: # do_perl URL FILENAME
  do_perl() {
    echo "trying perl..."
    perl -e "use LWP::Simple; getprint(shift @ARGV);" "$1" > "$2" 2>$tmp_dir/stderr
    rc=$?
    # check for 404
    grep "404 Not Found" $tmp_dir/stderr 2>&1 >/dev/null
  