[Rd] file.info() on file larger than 2GB
Prof Brian Ripley
ripley at stats.ox.ac.uk
Tue Aug 31 17:36:20 CEST 2004
This is a purely OS issue: your OS has not been set up so the fopen and
stat calls handle > 2Gb files. There is one R issue: the size will
overflow in file.info.
For example, under Solaris 64-bit applications can handle such files
whereas 32-bit ones need calls to stat64, fopen64 etc.
It seems a very exotic need, but if someone wants to find out how to use
the OS-specific ways to extend stat etc and supply patches, please do so.
We don't put OS-specific limitations on help pages.
On Tue, 31 Aug 2004, Roger D. Peng wrote:
> I've got a file that's approximately 2.2GB and it seems to be foiling
> file.info(). When I run `stat' from the shell I get
> zooey:> stat data.csv
> File: `data.csv'
> Size: 2271197563 Blocks: 4440280 IO Block: 4096 regular file
> Device: 342h/834d Inode: 9994308 Links: 1
> Access: (0644/-rw-r--r--) Uid: ( 500/ rpeng) Gid: ( 500/ rpeng)
> Access: 2004-08-31 09:50:04.000000000 -0400
> Modify: 2004-08-26 19:09:42.000000000 -0400
> Change: 2004-08-31 09:53:29.000000000 -0400
Take a look at the source code for stat, in coreutils.
> But, file.info() in R-devel gives me:
> > file.info("data.csv")
> size isdir mode mtime ctime atime uid gid uname grname
> data.csv NA NA <NA> <NA> <NA> <NA> NA NA <NA> <NA>
> I assume this has something to do with the underlying call to `stat'
> in `do_fileinfo'.
> This alone is not much of a problem but I also can't seem to be able
> to open a file connection to the same file. For example,
> > con <- file("data.csv")
> > open(con, "r")
> Error in open.connection(con, "r") : unable to open connection
> In addition: Warning message:
> cannot open file `data.csv'
> Also, interestingly,
> > file.exists("data.csv")
>  FALSE
> I take it all these things are related.
> Is it possible to fix this within R? Or should there be a note in the
> help pages?
> > version
> platform i686-pc-linux-gnu
> arch i686
> os linux-gnu
> system i686, linux-gnu
> status Under development (unstable)
> major 2
> minor 0.0
> year 2004
> month 08
> day 31
> language R
> R-devel at stat.math.ethz.ch mailing list
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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