Technically speaking, command line arguments should have a short form, which is a single hyphen followed by a single letter, and a long form, which is two hyphens followed by multiple letters. I've retained an improper form (long form with a single hyphen) for convenience but it may be removed in the future. The more immediate issue here is that your short form `-tr` has two letters when it should have one. Right now `-t` is taken by the `--tallies` option, but I'm planning on removing that option so you will be able to use `-t`.

Also, you need to increment the command line argument counter, the variable `i` or else subsequent arguments will not be read.