Use stderr for errors

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rm-improved"
-version = "0.11.2"
+version = "0.11.3"
 authors = ["[email protected]"]
 description = "rip: a safe and ergonomic alternative to rm"
 repository = "https://github.com/nivekuil/rip"

src/main.rs

@@ -41,14 +41,20 @@ struct RecordItem<'a> {
 
 fn main() {
     if let Err(ref e) = run() {
-        println!("Error: {}", e);
+        use ::std::io::Write;
+        let stderr = &mut ::std::io::stderr();
+        let errmsg = "Error writing to stderr";
+
+        writeln!(stderr, "error: {}", e).expect(errmsg);
 
         for e in e.iter().skip(1) {
-            println!("Caused by: {}", e);
+            writeln!(stderr, "caused by: {}", e).expect(errmsg);
         }
 
+        // The backtrace is not always generated. Try to run this example
+        // with `RUST_BACKTRACE=1`.
         if let Some(backtrace) = e.backtrace() {
-            println!("Backtrace: {:?}", backtrace);
+            writeln!(stderr, "backtrace: {:?}", backtrace).expect(errmsg);
         }
 
         ::std::process::exit(1);