basic cli usage

.direnv/nix-profile-.3389.9cac4585028

@@ -0,0 +1 @@
+/nix/store/qrxpcn4y4gfjv21rqring53sii49hysj-nix-shell-env

.envrc

@@ -0,0 +1 @@
+use nix

src/main.rs

@@ -1,5 +1,15 @@
 use clap::Parser;
 
-fn main() {
-    println!("Hello, world!");
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about=None)]
+struct Cli {
+    #[arg(short, long)]
+    configuration_file: Option<String>,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    println!("Hello, world!");
+    println!("{:?}", cli);
 }