Note to the author: Please don't have a command line flag that either means ( a valid local posix path ) or ( a username/handle from a specific online service that will be fetched over the network ). *nix cli tools are supposed to be unambiguous. I'd fork/issue/patch it, but I don't have a need to let people ssh into my any of my boxes. Just posting this here because its a valid learning opportunity that making something "easy" is not always the right choice in a cli tool, and that namespaces are important. What if I have a file named the same as a github user? Which thing will work? Will that behavior change unexpectedly? Best to make them different flags.