chore: nixos package

Author: rwxd

README.md

@@ -12,6 +12,32 @@ Or install with go:
 go get github.com/rwxd/vmrss
 ```
 
+### NixOS / Nix
+
+Add to your `flake.nix`:
+
+```nix
+{
+  inputs.vmrss.url = "github:rwxd/vmrss";
+  # Or use a specific version:
+  # inputs.vmrss.url = "github:rwxd/vmrss/v1.0.0";
+}
+```
+
+Then use in your configuration:
+
+```nix
+environment.systemPackages = [ inputs.vmrss.packages.${system}.vmrss ];
+```
+
+Or run directly:
+
+```bash
+nix run github:rwxd/vmrss -- -m <pid>
+# Or use a specific version:
+# nix run github:rwxd/vmrss/v1.0.0 -- -m <pid>
+```
+
 ## Usage
 
 ### Continuously monitor a process

flake.lock

@@ -0,0 +1,32 @@
+{
+  description = "A simple tool to show the memory usage of a process and its children";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+      in
+      {
+        packages.vmrss = pkgs.buildGoModule {
+          pname = "vmrss";
+          version = "0.1.0";
+          src = ./.;
+          vendorHash = null;
+        };
+
+        apps.default = {
+          type = "app";
+          program = "${self.packages.${system}.vmrss}/bin/vmrss";
+        };
+
+        devShells.default = pkgs.mkShell {
+          buildInputs = with pkgs; [ go ];
+        };
+      }
+    );
+}