Rust binding for OpenBSD's unveil(2).
```rust extern crate unveil;
use std::fs::File; use std::io::prelude::*; use unveil::unveil;
fn main() { let path = "public.txt"; let contents = b"Hello world!"; File::create(path).unwrap().write_all(contents).unwrap();
// Restrict filesystem view by only allowing read operations on the specified path
unveil(path, "r").unwrap();
// Reading from unveiled paths will succeed
let mut file = File::open(path).unwrap();
let mut buffer = Vec::new();
file.read_to_end(&mut buffer).unwrap();
assert_eq!(contents, &buffer[..]);
// Reading from paths which have not been unveiled will fail
assert!(File::open("/etc/passwd").is_err());
// Disable further calls to unveil
unveil("", "").unwrap();
// All calls to unveil will now fail
assert!(unveil(path, "rw").is_err());
} ```