So I had been working to get a full list of my NixOS Options.
Yes, I know there is the man pages and nixos-options, but I wanted a full list to do fuzzy searches with fzf.
The other caveat is that I wanted to build this without cloning nixpkgs and “cheating” by just editing the documentation code inline. I have resisted this temptation for ages now by using modules and overlays, and I wanted to keep it up.
The script is mostly just gutted sections of <nixpkgs/nixos/docs/manual>, but it adds a few critical additions, (tryEval on missing descriptions, and fake example paths) which normally cause crashes.
In any case here is the script in case it is useful to anyone.
I have it dumping JSON but you could easily swap out that last little bit for xml or whatever other output you want.
#! /usr/bin/env bash
echo $(nix-instantiate - --eval --show-trace <<EOF
with import <nixpkgs/nixos> { };
let
extraSources = [];
lib = pkgs.lib;
optionsListVisible =
lib.filter (opt: opt.visible && !opt.internal)
(lib.optionAttrSetToDocList options);
# Replace functions by the string <function>
substFunction = x:
if builtins.isAttrs x then lib.mapAttrs (name: substFunction) x
else if builtins.isList x then map substFunction x
else if lib.isFunction x then "<function>"
else if isPath x then toString x
else x;
isPath = x: (builtins.typeOf x) == "path";
optionsListDesc = lib.flip map optionsListVisible (opt: opt // {
description = let attempt = builtins.tryEval opt.description; in
if attempt.success then attempt.value else "N/A";
declarations = map stripAnyPrefixes opt.declarations;
}
// lib.optionalAttrs (opt ? example) {
example = substFunction opt.example; }
// lib.optionalAttrs (opt ? default) {
default = substFunction opt.default; }
// lib.optionalAttrs (opt ? type) {
type = substFunction opt.type; }
// lib.optionalAttrs
(opt ? relatedPackages && opt.relatedPackages != []) {
relatedPackages = genRelatedPackages opt.relatedPackages; }
);
genRelatedPackages = packages: let
unpack = p: if lib.isString p then { name = p; }
else if lib.isList p then { path = p; }
else p;
describe = args: let
title = args.title or null;
name = args.name or (lib.concatStringsSep "." args.path);
path = args.path or [ args.name ];
package = args.package or (lib.attrByPath path (throw
"Invalid package attribute path '\${toString path}'") pkgs);
in "<listitem>"
+ "<para><literal>\${lib.optionalString (title != null)
"\${title} aka "}pkgs.\${name} (\${package.meta.name})</literal>"
+ lib.optionalString (!package.meta.available)
" <emphasis>[UNAVAILABLE]</emphasis>"
+ ": \${package.meta.description or "???"}.</para>"
+ lib.optionalString (args ? comment)
"\n<para>\${args.comment}</para>"
+ lib.optionalString (package.meta ? longDescription)
"\n<programlisting>\${package.meta.longDescription}"
+ "</programlisting>"
+ "</listitem>";
in "<itemizedlist>\${lib.concatStringsSep "\n" (map (p:
describe (unpack p)) packages)}</itemizedlist>";
optionLess = a: b:
let
ise = lib.hasPrefix "enable";
isp = lib.hasPrefix "package";
cmp = lib.splitByAndCompare ise lib.compare
(lib.splitByAndCompare isp lib.compare lib.compare);
in lib.compareLists cmp a.loc b.loc < 0;
prefixesToStrip = map (p: "\${toString p}/") ([ ../../.. ] ++ extraSources);
stripAnyPrefixes = lib.flip (lib.fold lib.removePrefix) prefixesToStrip;
###############################################################################
# This is the REAL meat of what we were after.
# Output this however you want.
optionsList = lib.sort optionLess optionsListDesc;
optionsJSON = builtins.unsafeDiscardStringContext (builtins.toJSON
(builtins.listToAttrs (map (o: {
name = o.name;
value = removeAttrs o [
# Select the fields you want to drop here:
"name" "visible" "internal" "loc" "readOnly" ];
}) optionsList)));
in optionsJSON
EOF
) | sed 's/\\\\/\\/g' | sed 's/\\"/"/g' | head -c -2 | tail -c +2
# vim: ft=sh
