I installed pdfinfo with Homebrew Cask:
brew cask install pdfinfo
It's successfully installed. But it's not activated as a command in the shell:
> pdfinfo
-bash: pdfinfo: command not found
What I don't understand is that I did the exact same procedure with pdftotext (installed with Homebrew Cask), and it works fine:
> brew cask install pdftotext
(...)
> pdftotext
pdftotext version 3.03
Copyright 1996-2011 Glyph & Cog, LLC
...