rot13

Rot-13 encryption and decryption (written in rust)

``` USAGE: rot13 [FLAGS] [OPTIONS] --decrypt --encrypt

FLAGS: -d, --decrypt decrypt the provided input -e, --encrypt encrypt the provided input -h, --help Prints help information -V, --version Prints version information

OPTIONS: -i, --input the input file to use. defaults to stdin -o, --output the output file to use. defaults to stdout ```

Library usage:

```rust use rot13::{rot13_slice, Mode};

fn main() { let input = b"Hello, World!";

// try encryption
let encrypted = rot13_slice(Mode::Encrypt, input);
println!("{}", ::std::str::from_utf8(&encrypted).unwrap());

// since case is preserved during encryption, the decrypted
// product should be the same as the original input
let decrypted = rot13_slice(Mode::Decrypt, &encrypted);
assert_eq!(input, decrypted.as_slice());

} ```