Probably best to do 
```rust
use std::io;
let mut reader = io::stdin(); 

let mut bytes = [0, .. 10];
reader.read(..); 
if reader.eof() { println("..."); }
```

rather than call `stdin()` twice. (Since most other readers won't return the same instance if you create them twice; i.e. each `File::open(path)` creates a new file reader handle.)