Robert Heller <[EMAIL PROTECTED]> writes:
> "Peter Nolan" <[EMAIL PROTECTED]>,
> In a message on 14 Apr 2006 07:10:59 -0700, wrote :
>
> "N> Hi All,
> "N> I am running some C++ I wrote having been compiled in G++. When writing
> "N> to a file I get 'file size limit exceeded' as a message when the file
> "N> size gets to 2,147,483,647.
Are you using 'std::fstream', 'FILE*', or 'int fd' to write these files?
Using 'fstream', I get the same behavior as you do, regardless
of whether I use '-D_FILE_OFFSET_BITS=64'.
Using 'FILE *', I get "File size limit exceeded" without
-D_FILE_OFFSET_BITS=64, but can write 4GB file when compiled with
-D_FILE_OFFSET_BITS=64.
[In the process of experimentation, I have corrupted my old reiserfs
/home filesystem, which is why my reply is 2 days late ;-[
Since 'fstream::write' calls 'fwrite' to do the actual writing,
the problem must be in how libstdc++ was compiled.
In fact, looking at strace output, I observe:
// using std::fstream
open("junk.out", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3
// using fopen()/fwrite()
open("junk.out", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0666) = 3
Running under debugger, I see that std::fstream version calls
[EMAIL PROTECTED], while the fopen()/fwrite() version calls fopen64().
Looking further into gcc-3.4.0/libstdc++ sources, I see this:
__basic_file<char>::open(const char* __name ...
#ifdef _GLIBCXX_USE_LFS
if ((_M_cfile = fopen64(__name, __c_mode)))
#else
if ((_M_cfile = fopen(__name, __c_mode)))
#endif
So, to solve the problem, you must rebuild libstdc++ with
-D_GLIBCXX_USE_LFS. It appears, that newer versions of g++ (at
least 3.4.0) automatically check for and enable this, but the
default g++ 3.3.3 (as shipped with Fedora Core 2) either didn't,
or was compiled on a non-LFS filesystem.
> Exactly what version of red hat linux are you using? Which kernel
> version? Which GLibc version?
This is likely irrelevant -- other programs *can* write large files:
> "N> We have tried creating larger
> "N> files with other programs and they work ok
which means his kernel and glibc are perfectly fine.
Cheers,
--
In order to understand recursion you must first understand recursion.
Remove /-nsp/ for email.
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