Hi Mikko, I was bitten by this recently and I think some of the replies are missing the point. As I understand it, the problem consists of these elements:
1. When R starts, it creates a directory like /tmp/RtmpVIeFj4 2. Right after R starts I can create files in this directory with no error 3. After some hours or days I can no longer create files in this directory, because it has been deleted If R expected the directory to be deleted at random, and if we expect users to call dir.create every time they access tempdir, then why did R create the directory for us at the beginning of the session? That's just setting people up to get weird bugs, which only appear in difficult-to-reproduce situations (i.e. after the session has been open for a long time). I think before we dismiss this we should think about possible in-R solutions and why they are not feasible. Are there any packages which would break if a call to 'tempdir' automatically recreated this directory? (Or would it be too much of a performance hit to have 'tempdir' check and even just issue a warning when the directory is found not to exist?) Should we have a timer which periodically updates the modification time of tempdir()? What do other long-running programs do (e.g. screen, emacs)? Thank you, Frederick P.S. I noticed that dir.create does not seem to update the access or modification time of the file. So there is also a remote possibility that the directory could be "cleaned up" in between calling 'dir.create()' and putting a file in it. Maybe this is nitpicky, but if we accept that the *really* correct practice is more complicated than just calling 'dir.create()', this also argues for putting the proper invocations into some kind of standard function - either 'tempdir()' or something else. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
