On Tue, 2009-10-20 at 14:52 -0400, Bill Cole wrote:
And also: I think (guess) that behavior is required by POSIX, but it would be nice if someone could verify that. :) The behavior being: seeking in a fd is affects all processes that have the same fd open. (Simple IPC, yay.)
As I read them, the various man pages for dup() confirm that. In addition to those man pages' statements about standards compliance, the fact that dup() is in 4BSD's unistd.h is also a strong clue. When looking for this sort of info, an invaluable resource is the man page archive at http://www.freebsd.org/cgi/man.cgi which has man collections from many different branches of the Unix family tree going back to Unix 7th edition and BSD 2.8.
Thanks. I've been using man.freebsd.org to look up FreeBSD's man pages, but I hadn't noticed it has a lot more.