matthew green wrote:
> EPERM?

Not the way I read it ... EPERM is specifically about whether
the open would be allowed by the checks on your identity and
the mode bits on the node.  But you can have all the permissions
in the world and when you try to open /dev/cardpunch for reading,
something's still gotta give. It's an inherent device capability
issue, not a permission issue.

-Chap