add Nix flake, shell

flake.nix

@@ -0,0 +1,98 @@
+{
+  description = "The DBSQL library, a mixup of SQLite and Berkeley DB";
+
+  nixConfig = {
+    bash-prompt = "\\[\\e[34;1m\\]nix ~ \\[\\e[0m\\]";
+  };
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+  inputs.pre-commit-hooks.url = "github:cachix/pre-commit-hooks.nix";
+  inputs.nix-github-actions.url = "github:nix-community/nix-github-actions";
+  inputs.nix-github-actions.inputs.nixpkgs.follows = "nixpkgs";
+
+  outputs = { self, nixpkgs, flake-utils, pre-commit-hooks, nix-github-actions }:
+    let
+      inherit (nixpkgs) lib;
+      officialRelease = false;
+
+      #version = "DBSQL ${DBSQL_VERSION}: (${versionSuffix})";
+      version = "DBSQL 0.3.1: (${versionSuffix})";
+      versionSuffix =
+        if officialRelease
+        then ""
+        else "pre${builtins.substring 0 8 (self.lastModifiedDate or self.lastModified or "19700101")}_${self.shortRev or "dirty"}";
+
+      supportedSystems = [ "x86_64-linux" ];
+      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+      nixpkgsFor = forAllSystems (system: import nixpkgs {
+        inherit system;
+        overlays = [ self.overlay ];
+      });
+
+    in
+      flake-utils.lib.eachDefaultSystem (system:
+        let
+          pkgs = import nixpkgs {
+            inherit system;
+
+            overlays = [
+
+              (final: prev: {
+                dbsql = with final; stdenv.mkDerivation rec {
+                  inherit version;
+                  inherit system;
+                  pname = "dbsql";
+                  src = self;
+                  configureFlags = [
+                    "--host ${system}"
+                  ];
+                  nativeBuildInputs = [ autoreconfHook ];
+                  meta = {
+                    changelog = "https://git.burd.me/greg/dbsql/raw/branch/main/ChangeLog";
+                    downloadPage = "https://git.burd.me/greg/dbsql/releases";
+                    homepage = "https://github.com/gburd/dbsql";
+                    license = "https://github.com/gburd/dbsql/LICENSE";
+                    mainProgram = "dbsql";
+                    maintainers = [ "Greg Burd <greg@burd.me>" ];
+                    platforms = supportedSystems;
+                  };
+                };
+              })
+            ];
+
+            checks = {
+              pre-commit-check = pre-commit-hooks.lib.${system}.run {
+                src = ./.;
+                hooks = {
+                  nixpkgs-fmt.enable = true;
+                };
+              };
+            };
+
+            devShell = nixpkgs.legacyPackages.${system}.mkShell {
+              inherit (self.checks.${system}.pre-commit-check) shellHook;
+            };
+
+          };
+
+        in rec {
+          packages = {
+            inherit (pkgs) dbsql;
+
+            githubActions = nix-github-actions.lib.mkGithubMatrix {
+              checks = nixpkgs.lib.getAttrs [ "x86_64-linux" "x86_64-darwin" ] self.packages;
+            };
+          };
+          packages.default = self.packages.${system}.dbsql;
+          packages.container = pkgs.callPackage ./container.nix { package = packages.default; };
+
+          apps.dbsql = flake-utils.lib.mkApp { drv = packages.default; };
+          apps.${system}.default = apps.dbsql;
+
+          devShells.default = import ./shell.nix { inherit pkgs; };
+        }
+      );
+}

shell.nix

@@ -0,0 +1,26 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+  # nativeBuildInputs is usually what you want -- tools you need to run
+  nativeBuildInputs = with pkgs.buildPackages; [
+    act
+    autoconf
+    db4
+    ed
+    gcc
+    gdb
+    gettext
+    libtool
+    m4
+    perl
+    ripgrep
+    tcl-8_5
+  ];
+
+  buildInputs = with pkgs; [
+    glibc.out
+    glibc.static
+  ];
+
+  DOCKER_BUILDKIT = 1;
+}