list-attributes.sh

#!/usr/bin/env bash

#productization: don't use <nixpkgs>
IFS='' read -r -d '' expression <<"EOF"
{ inputPath }:
let
  pkgs = import <nixpkgs> {};
  input = import inputPath;

  pathString = builtins.foldl'
    (current: attr:
      (if current == "" then "" else current + ".") + attr
    ) "";

  isDerivation = x: x ? "type" && x.type == "derivation";

  discoverBuildAttributes = currentPath: currentSet:
    let
      accumulate = accumList: name:
        let
          value = currentSet."${name}";
          attrsInSet =
            if isDerivation value then [ (pathString (currentPath ++ [ name ])) ]
            else if builtins.typeOf value == "set" then discoverBuildAttributes (currentPath ++ [ name ]) value
            else [ ];
        in
        accumList ++ attrsInSet;
    in
    builtins.foldl' accumulate [ ] (builtins.attrNames currentSet);
in
  # Discover all build attributes starting from the root
  discoverBuildAttributes [ ] input
EOF

inputPath=$(readlink -f $1)
# productization: check if this is an existing file

nix-instantiate --eval --json --strict -E "$expression" --argstr inputPath "$inputPath"