Examples: allow passing URL via CLI

examples/simple.rs

@@ -6,13 +6,29 @@
 #[cfg(not(target_arch = "wasm32"))]
 #[tokio::main]
 async fn main() -> Result<(), reqwest::Error> {
-    let res = reqwest::get("https://hyper.rs").await?;
+    // Some simple CLI args requirements...
+    let url = match std::env::args().nth(1) {
+        Some(url) => url,
+        None => {
+            println!("No CLI URL provided, using default.");
+            "https://hyper.rs".into()
+        }
+    };
 
-    println!("Status: {}", res.status());
+    eprintln!("Fetching {:?}...", url);
+
+    // reqwest::get() is a convenience function.
+    //
+    // In most cases, you should create/build a reqwest::Client and reuse
+    // it for all requests.
+    let res = reqwest::get(url).await?;
+
+    eprintln!("Response: {:?} {}", res.version(), res.status());
+    eprintln!("Headers: {:#?}\n", res.headers());
 
     let body = res.text().await?;
 
-    println!("Body:\n\n{}", body);
+    println!("{}", body);
 
     Ok(())
 }