added readline example

Author: BartMassey

README.md

@@ -13,4 +13,5 @@ in a controlled repository now.
 * `closures.rs`: closure examples
 * `lifetimes.rs`: simple lifetime example
 * `rc`: examples with `RefCell` and `Rc`
+* `readline`: example of readline with error handling
 * `error`: example of creating a custom error

readline.rs

@@ -0,0 +1,16 @@
+/// Read from stdin with default.
+fn main() {
+    use std::io::BufRead;
+    let stdin = std::io::stdin();
+    let mut stdin = stdin.lock();
+    let mut line = String::new();
+    match stdin.read_line(&mut line) {
+        Ok(_) => {
+            print!("{}", line);
+        }
+        Err(e) => {
+            eprintln!("read_line: {}", e);
+            std::process::exit(1);
+        }
+    }
+}