Subj : Re: Large Files
To   : borland.public.cpp.borlandcpp
From : Bob Gonder <notbg@notmindspring.invalid>
Date : Sat Sep 13 2003 04:07 pm

Trandog wrote:

>==============================================================================
> From my standard:  (bcc32)
>Borland C++ 5.3 for Win32 Copyright (c) 1993, 1998 Borland International
>=============================================================================
> From the free download  (bcc32)
>Borland C++ 5.5.1 for Win32 Copyright (c) 1993, 2000 Borland

Of the 3, that is the newest, and the one I use just fine.
Did you apply all of the patches for it?

>============================================================================
> From CBuilder: the about box states:
>Professional 3.0  (Build 3.70)
>=============================================================================
>
>The system problem I mentioned is that the command:
>"c:\Program Files\myprog.exe"  "Arg  1"  "arg  2" will not work as the string in 
>system() under XP, but will under Win9x.  For Win XP, NT, 2K, the command has to 
>be: ""c:\Program Files\muprog.exe"  "Arg  1"  "arg  2"", but that does not work 
>in Win9x.

So, you're saying what?
system("c:\Program Files\myprog.exe"  "Arg  1"  "arg  2"); works???
I don't think so. But this should
system( "\"c:\\Program Files\\myprog.exe\"  \"Arg  1\"  \"arg  2\"" );

>My 5.3 C compiler works fine with the Win API calls for large files with several 
>exceptions:
>
>If I write a lot of short records with WriteFile, the system hangs.  If I buffer 

How short? One Byte?

What options (if any) for dwFlagsAndAttributes do you use when opening
those files? In a multi-user system, you want FILE_FLAG_WRITE_THROUGH.
You should also have one of FILE_FLAG_RANDOM_ACCESS or
FILE_FLAG_SEQUENTIAL_SCAN depending on how you use the file.

>the writes myself, and write larger records, I have no problems.  The very same 
>code with the Win API routines replaced with file stream routines works with no 
>problems, except when the file sizes get too large.  Also, in WinXP, the 
>ReadFile operations randomly fail.

In what way do they fail?  Do you check returned values?

>  (I beleive it either related to reading very 
>short records, or file mis-positioning by SetFilePointer.)  The .exe works 
>correctly in Win9x.

If the hFile file handle was opened with the FILE_FLAG_NO_BUFFERING
flag set, an application can move the file pointer only to
sector-aligned positions.
So, don't set that flag in CreateFile().

.