Examples: allow passing URL via CLI

examples/blocking.rs

@@ -4,16 +4,28 @@
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     env_logger::init();
 
-    println!("GET https://www.rust-lang.org");
+    // 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()
+        }
+    };
 
-    let mut res = reqwest::blocking::get("https://www.rust-lang.org/")?;
+    eprintln!("Fetching {:?}...", url);
 
-    println!("Status: {}", res.status());
-    println!("Headers:\n{:?}", res.headers());
+    // reqwest::blocking::get() is a convenience function.
+    //
+    // In most cases, you should create/build a reqwest::Client and reuse
+    // it for all requests.
+    let mut res = reqwest::blocking::get(url)?;
+
+    eprintln!("Response: {:?} {}", res.version(), res.status());
+    eprintln!("Headers: {:#?}\n", res.headers());
 
     // copy the response body directly to stdout
     res.copy_to(&mut std::io::stdout())?;
 
-    println!("\n\nDone.");
     Ok(())
 }