jons-iMac:contrib jon$ protoc
-bash: protoc: command not found
jons-iMac:contrib jon$ brew install protobuf
==> Downloading https://homebrew.bintray.com/bottles/protobuf-3.3.2.sierra.bottle.tar.gz
######################################################################## 100.0%
==> Pouring protobuf-3.3.2.sierra.bottle.tar.gz
==> Using the sandbox
==> Caveats
Editor support and examples have been installed to:
  /usr/local/opt/protobuf/share/doc/protobuf

Python modules have been installed and Homebrew's site-packages is not
in your Python sys.path, so you will not be able to import the modules
this formula installed. If you plan to develop with these modules,
please run:
  mkdir -p /Users/jon/Library/Python/2.7/lib/python/site-packages
  echo 'import site; site.addsitedir("/usr/local/lib/python2.7/site-packages")' >> /Users/jon/Library/Python/2.7/lib/python/site-packages/homebrew.pth
==> Summary
🍺  /usr/local/Cellar/protobuf/3.3.2: 260 files, 16.1MB
jons-iMac:contrib jon$