Quoth Niklas Hambüchen
On 25/07/15 21:09, Donn Cave wrote:
But there are other things that could turn up. For example, you could use flock(2) (Berkeley, not POSIX fcntl lock) to keep an advisory file lock until the exec exits. If the file is closed prematurely, you lose the lock, and ... whatever happens then.
This is a very valid point. Applications that rely on this will break by changing the default here.
... and you go on to demonstrate that you didn't really take the point I was trying to make. How did you find out about this flock(2) scenario? Do you suppose that this is the only one, because you and I don't know of any more? My point is not that the whole thing might hinge on whether we can deal with flock locking in this scenario, it is that when we think about reversing ancient defaults in the underlying system, we have to assume the risk of obscure breakage as a result. To worry about the flock problem now is to miss the point. And again, this half-a-fix inconsistently applies to only files created by open(2), and not to pipes, sockets and whatever else creates a file descriptor in some other way, so if it's a real problem, it seems you must address it in some other way anyway. Donn