How to install GNU base64 on Mac OS X? I'm trying to run linux scripts on the mac, but even brew's updated base64 doesn't support -w0. I want something close to base64 (GNU coreutils) 8.22 

Instead of base64 1.5 from brew or the unknown version MacOs ships with whose binary's md5 is 718fe34e4012999c180f807fe323e7f1

I've had great luck by using iTerm and loading .bashrc to replace most bsd/mac utilities with gnu ones.

P.S. There is little reason to install the one from brew, as it line breaks by default and has no way to disable that "feature".
https://github.com/Homebrew/brew/issues/4558#issuecomment-408225004

Brew does have the gnu version in the coreutils package. It installs it as gbase64