A program that can encode and decode text using a ceaser cipher.

Usage: ./ceaser [-f <input-file>] [-o <output-file>] [-h] <-d or -e>

Options:
    -f <input-file>  => The file to use as input. If excluded, stdin will be
                        used.

    -o <output-file> => The file to write to. If excluded, stdout will be
                        used.

    -d               => The input will be decoded using the secret alphabet.

    -e               => The input will be encoded using the secret alphabet.
                        This is the default function.

    -h               => Prints usage information and exits.