Simple implementation of Vigenere cipher in Rust

Works only with capital ASCII letters

Build and run with vigenere --help to get help. Can work with files or standard stream or a mix of both. Errors are output to STDERR.

Usage:

• To work with files: vigenere -d -i ciphertext.txt -o plaintext.txt --key <keyword>
• To work with streams: cat plaintext.txt | vigenere --key <keyword>. Otputs to STDOUT.
• To work with mixed IO: cat ciphertext.txt | vigenere --decipher --key <keywords> -o ./plaintext.txt or vigenere -i plaintext.txt --key <keyword> (outputs to STDOUT) or cat ./plaintext.txt | vigenere --key <keyword> > ./ciphertext.txt

Will prioritize files if --input and/or --output parameters are given.