Fixed bug on incorrect command, missing carriage return on cd

src/lib.rs

@@ -127,12 +127,16 @@ pub mod shell {
                     return Err(CmdOutput::from_values(format!("Could not parse command {:?}", e), -1));
                 },
             };
+            if parts.len() < 1 {
+                return Err(CmdOutput::from_values(String::from("Could not parse command"), -1));
+            }
             let command = parts[0].as_str();
             let args = Vec::from(&parts[1..]);
 
             match command {
                 "cd" => {
                     change_dir(&args, &mut previous_command)?;
+                    print!("\r\n");
                 },
                 "history" => {
                     let next = commands.peek().is_some();