On Thu 23-05-19 15:35:18, Christian Brauner wrote: > So let's say the user tells me: > - When the "/A/B/C/target" file appears on the host filesystem, > please give me access to "target" in the container at a path I tell > you. > What I do right now is listen for the creation of the "target" file. > But at the time the user gives me instructions to listen for > "/A/B/C/target" only /A might exist and so I currently add a watch on A/ > and then wait for the creation of B/, then wait for the creation of C/ > and finally for the creation of "target" (Of course, I also need to > handle B/ and C/ being removed again an recreated and so on.). It would > be helpful, if I could specify, give me notifications, recursively for > e.g. A/ without me having to place extra watches on B/ and C/ when they > appear. Maybe that's out of scope... I see. But this is going to be painful whatever you do. Consider for example situation like: mkdir -p BAR/B/C/ touch BAR/B/C/target mv BAR A Or even situation where several renames race so that the end result creates the name (or does not create it depending on how renames race). And by the time you decide A/B/C/target exists, it doesn't need to exist anymore. Honestly I don't see how you want to implement *any* solution in a sane way. About the most reliable+simple would seem to be stat "A/B/C/target" once per second as dumb as it is. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
