FZF Fuzzy search for NixOS Options and Packages

nix-search.sh

#! /usr/bin/env bash

# Provided a list of package and option names (provided by my `writeOpts.sh` and 
# `writePacks.sh` scripts), fuzzy search package and options information.
# The selection's definition will be opened in vim (as readonly) for viewing.
# NOTE: This script opens the result in a new URxvt window, you most likely will want
#       to change that to open in the current window, or your own Terminal Emulator of
#       choice. The current implementation is intended for use with a temporary XMonad
#       scratchpad, which dies immediately after exiting (thus a new URxvt window is
#       required).

# See if options and packages are outdated
if [[ $1 == "-o" ]]; then
    TARGET="/etc/nixos/bin/options.txt"
    PR="NixOS Options> "
    PREVIEW="nixos-option"
    function seeDef () {
      nixos-option "${1}" | tail -n 2 | head -n 1 | cut -d "\"" -f 2
    }
else
    TARGET="/etc/nixos/bin/packages.txt"
    PR="Nixpkgs> "
    PREVIEW="nix-env -qa --description -A"
    function seeDef () {
      nix-env -qa --json -A "${1}" \
        | jq ".\"${1}\".meta.position" \
        | cut -d "\"" -f 2 | cut -d ":" -f 1
    }
fi

SELECTION=`cat ${TARGET}                                \
  | fzf --prompt="${PR}" --reverse                      \
        --preview-window=wrap:70%                     \
        --preview="echo -e \"{1}\n\"; ${PREVIEW} {1}"`

echo ${SELECTION}
DEFPATH=`seeDef ${SELECTION}`
echo ${DEFPATH}
urxvtc -tr -sh 8 -e zsh -ic "vim -R -c 'nnoremap q :q!<CR>' ${DEFPATH}; vimb"

# Do updates to package/options lists
NIXAGE=`date -r /etc/nixos/common.nix +%s`
OPTSAGE=`date -r /etc/nixos/bin/options.txt +%s`
PACKSAGE=`date -r /etc/nixos/bin/packages.txt +%s`

if [[ ( $(( ($NIXAGE - $OPTSAGE) / 60)) -gt 5) ]];
then ./writeOpts & fi

if [[ ( $(( ($NIXAGE - $PACKSAGE) / 60)) -gt 5) ]];
then ./writePacks & fi

#vim: sh

writeOpts.sh

#! /usr/bin/env bash

# Generates a list of all options on a given system.
# The generated list can be used directly with `nixos-option` to query information.

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 | \
    jq 'keys | .[]' | sed 's/^"\(.*\)"$/\1/g' > options.txt

# vim: ft=sh

writePacks.sh

#! /usr/bin/env bash

# Dumps a list of all available Nixpkgs.
# I have also added references to all Haskell Packages.
# You can easily append other packages, ie Node, Python, etc

nix-env -qa -P | awk '{print $1}' > packages.txt
nix-env -f '<nixpkgs>' -qaP -A haskellPackages | \
    awk '{print "nixos."$1}' >> packages.txt 

#vim: ft=sh