No uname and gname in file.info R-package

Question

I would like to get information about the last file user or creator of some files in R and tried to use file.info package to read uname but file.info does not provide such in my 3.5.1 R version

    file.info("test.xlsx")
          size isdir mode               mtime               ctime               atime exe
test.xlsx 8833 FALSE  666 2018-09-11 14:01:33 2018-09-11 14:01:33 2018-09-11 14:01:33  no

Thank you in advance

Answer 1

I imagine you are on a Windows system.

From ?file.info (bold-face mine):

The uid, gid, uname and grname columns may not be supplied on a non-POSIX Unix-alike system, and will not be on Windows .