Re: dd new iflag= oflag= flags directory, nolinks

[Paul Eggert]

Phillip Susi <address@hidden> writes:

> You can't open() and write() to a directory, so how does it make
> any sense to ask dd to set O_DIRECTORY?

You can open a directory without writing to it.  Something like this:

   $ mkdir foo
   $ dd if=foo iflag=directory count=0
   0+0 records in
   0+0 records out
   0 bytes (0 B) copied, 2e-05 seconds, 0 B/s

You can think of this as a way to do a "test -d foo && test -r foo"
atomically, without race conditions.  Admittedly this is somewhat
twisted, but the new documentation does say that iflag=directory is of
"limited utility"....