问题
(null).1001.1001
What is this folder? Where does it come from?
drwxrwxrwx 49 appusr appusr 4096 Jan 7 21:52 (null).1001.1001
I think it has something to do with Mr. Root impersonating Mr. AppUsr in a background task, but I posted to AskUbuntu last week, and nobody there recognized it.
Why am I asking? Well ...
On an Ubuntu box, I have a restricted-access applications user who is uid 1001 and gid 1001. Root launches Rserve under that user during boot. The Rserve session is writing into a Windows CIFS share. All seems to be functioning as intended ...
I'm finding these folders peppered throughout the application user's file tree:
drwxrwxrwx 49 appusr appusr 4096 Jan 7 21:52 (null).1001.1001
I'm finding these subfolders in various folders. Each of these subfolders is different, but they seem to contain partial temporary files, like stuff that I extracted from a tarball, or partial pdf writes.
My primary interest in these folders is that I've found that sometimes I need them and don't have them. There's a particular operation can work or fail depending on whether or not this folder is present. When writing a PDF from inside a knitr document that I call remotely from Rserve, I get this error message
## Error in plot.new(): cannot open file '', reason No such file or directory
I can't find an R reason for this, and it works when called from an rstudio-server session or from a Windows Rstudio IDE, but when called from Rserve, it seems to depend on having that folder present in the filesystem, and I'm quite sure that I didn't put it there! What is it?
来源：https://stackoverflow.com/questions/34883386/what-is-folder-null-1001-1001