properly checking version in client apps

[jbenet]

We're writing https://github.com/jbenet/go-ipfs/ -- a mountable filesystem -- and using osxfuse underneath the hood. we noticed that earlier versions caused kernel panics in some cases (as discussed + fixed in your update logs), so we want to make sure all our users are on 2.7.0+.

We thought about simply comparing the version in sysctl osxfuse.version.number, but we got a user for whom sysctl osxfuse.version.number (and sysctl osxfuse for that matter) returned

> sysctl osxfuse.version.number
top level name osxfuse in osxfuse is invalid

The user runs OS X Mountain Lion, has osxfuse 2.7.2 installed (pref pane shows up. see discussion here: https://botbot.me/freenode/ipfs/2014-11-03/?msg=24718568&page=1)

So, my questions are:

1. is osxfuse not setting its sysctl options normal?
2. what is the correct way to check the installed osxfuse version? is there a better way?

Thanks!

[bfleischer]

1. is osxfuse not setting its sysctl options normal?

The sysctls are only available after the osxfuse kernel extension has been loaded. Trying to access the version number without osxfuse being loaded will result in the following error message.

$ sysctl osxfuse.version.number
top level name osxfuse in osxfuse.version.number is invalid

1. what is the correct way to check the installed osxfuse version? is there a better way?

You can use function osxfuse_version() declared in /usr/local/include/osxfuse/fuse/fuse_darwin.h for this purpose. It returns the version string, e.g. 2.7.2. The kernel extension does not have to be loaded for this.

[jbenet]

Thanks for the response @bfleischer

For posterity, I made https://github.com/jbenet/go-fuse-version to get at the osxfuse_version in Go.