[Rd] file.info() on WinXP/NTFS > 2Gb
hb at maths.lth.se
Sat Feb 18 20:33:49 CET 2006
on WinXP Pro SP2 with NTFS, I noticed that file.info() under
Rv2.2.1pat (2006-02-09) does not report the correct file size if the
file is >= 2^31 bytes (2GB). Is this problem known? Is this related
to the note in ?file.info:
"Some (broken) systems allow files of more than 2Gb to be created but
not accessed by the 'stat' system call. Such files will show up as
non-readable (and very likely not be readable by any of R's input
# Create a 2Gb(!) file, report file.info()$size, and remove the file.
fname <- "tmp.Rbin";
con <- file(fname, open="w+b");
size <- 2^31-1; # OK
size <- 2^31; # Not OK
seek(con, where=size-1, rw="write");
writeBin(con=con, as.integer(0), size=1);
With size = c(2^31-1,2^31), file.info() reports file size
c(2147483647,-2147483648). This looks to me like a non-signed to
signed integer case.
Note that the above code does indeed create files >2Gb on WinXP with
NTFS; I've created files about 6Gb this way.
BTW, about seek() on Windows: I noticed the warning about using
seek() on Windows (see ?seek): "We have found so many errors in the
Windows implementation of file positioning that users are advised to
use it only at their own risk, and asked not to waste the R
developers' time with bug reports on Windows' deficiencies.". Not
going to bug report, but I haven't noticed any problems this far.
What errors/symptoms are expected? Is regardless of file system used,
e.g. FAT, NTFS?
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