linuxgeek: [nslu2-linux] Re: Problem with perl and large files

Tuesday, December 1, 2009

[nslu2-linux] Re: Problem with perl and large files

Hi Brian,

thank you for the very fast answer!
Unfortunately it seems that the issue remains, so can you explain what you mean with "so the problem is in user space"?
Is it a perl bug or a glibc issue from the qnap firmware?
I found an old discussion by googling this issue. See
http://www.justskins.com/forums/about-stat-problem-49666.html
A "perl -V" did not show any -D_FILE_OFFSET_BITS=64 string on my QNAP, but "uselargefiles=define". On all my other linux boxes this command shows -D_FILE_OFFSET_BITS=64 as ccflags. But if stat64() is called from perl binary than it seems that this option have applied.
Very mysterious.

Thank you in advance

Jörg

--- In nslu2-linux@yahoogroups.com, "Brian" <b88zhou@...> wrote:
>
> Doing a strace on a file > 2GB clearly shows that stat64 call has succeeded, so the problem is in user space.
>
> stat64("big-file", {st_mode=S_IFREG|0777, st_size=2200331748, ...}) = 0
>
> -Brian
>
> --- In nslu2-linux@yahoogroups.com, "joerg_kuehne" <joerg_kuehne@> wrote:
> >
> > Hi,
> >
> > I hope, that anyone in this group can give me a hint about the maintainer of the perl ipkg-package of the cs08q1armel branch.
> > I found an issue with the pert stat() function, that fails for files larger than 2GByte on my QNAP TS119. This function is used from the rsnapshot-diff script to get all informations about a certain file for comparing different backup snapshots. It seems that perl is compiled without 64Bit support for file sizes, with 32Bit one can only store size numbers up to 2GByte. Here a little test script to verify this issue.
> >
> > test.pl
> > --- cut here ---
> > #! /opt/bin/perl
> >
> > @mystat = stat($ARGV[0]);
> > print "$ARGV[0]: file size: $mystat[7]\n";
> > --- cut here ---
> >
> > Run test.pl FILE
> >
> > If file is smaller than 2GByte it will display the right file size, if it is larger then the file size will be empty caused by the failed stat().
> > Can anyone tell me why perl is compiled without the
> > -D_FILE_OFFSET_BITS=64 option? Is it a restriction of the ARM architecture or glibc? Or has the usage of this option unwanted side effects or was it simply forgotten?
> > Thank you in advance
> >
> > Jörg
> >
>