This is a simple generator for diceware passphrases written in Ruby. It uses SecureRandom for random number generation, which in turn uses openssl, /dev/urandom or the Windows API (in that order).
The wordlist parser is not very picky. The only requirement is that each word definition must have its own line in the form of <id> <whitespace character> <word>. Every line not matching that format will be ignored.
You can select which wordlist to use by specifying the -w flag. The parameter can be a local path or a URL. By default it will use the standard English wordlist. Please note that the PGP signature is completely ignored at the moment.
The default length is 6 words, you can change that by specifying the -l flag.
$ ./dice.rb --help