After running:

env  ; #from with in terminal

I see the following output:


What is this environment variable used for? Not really finding anything about what its for and why it is set by default.


1 Answer 1


PubSub is the backend for how Safari and Mail handle RSS feeds. There are command line utilities too. From the pubsub man page:

pubsub -- Utility for managing RSS/Atom subscriptions via the PubSub framework

This variable is just part of that process.

The ability to read RSS feeds in Safari is going away in Mountain Lion, but I don't know if the entire RSS infrastructure is going away too.

  • 1
    For information, it's still here on 10.11.5.
    – Maen
    Aug 24, 2016 at 16:32
  • 1
    For information, it's still here on 10.13.6
    – Mecki
    Sep 3, 2018 at 12:54
  • 1
    Command still present on 10.14.5
    – adib
    Jun 21, 2019 at 2:29

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