How to obtain file size through HTTP

http://stackoverflow.com/questions/4497759/how-to-get-remote-file-size-from-a-shell-script

$ curl --head --location --silent "https://media.githubusercontent.com/media/ArsenShnurkov/shnurise-tarballs/master/mono-4.5.2_p2016061606.tar.bz2" | grep Content-Length
Content-Length: 82657303