strange issue with reading files...

[Robert Anderson]

On Jan 4, 2008 9:53 AM, rory <rorywalsh at gmail.com> wrote:

>
> On Jan 4, 7:14 pm, w... at 61131.com wrote:
> > Moin Rory,
> >
> > did You open the file in binary mode? The default is text mode which
> could result in wrong positioning.
> >
> > Hope this helps
> > Friedrich
> >
> > ----- Original Message -----
> > From: "rory" <rorywa... at gmail.com>
> >
> > Newsgroups: comp.soft-sys.wxwindows
> > To: <wx-us... at lists.wxwidgets.org>
> > Sent: Friday, January 04, 2008 5:54 PM
> > Subject: strange issue with reading files...
> >
> > > I've spent to whole day trying to figure out how do the following in a
> > > wxwidget application:
> > > 1) open a binary file, an .exe to be precise,
> > > 2) read the last 10 chars from the end
> > > 3) offset the file by the value contained in those last 10 chars
> > > 4) retrieve everything from there till the end of the file.
> >
> > > I have it working without any problem in a non wxWidgets program but
> > > as soon as I try to do it from my wx app it doesn't work. This is the
> > > code I'm using:
> >
> > >  std::string str, csdText;
> > >  char buf[10];
> > >  fstream inFile( appName.c_str());
> > >  if(!inFile)  cerr << "Error";
> > >  inFile.seekg(-10, ios::end);
> > >  inFile.get(buf, sizeof(char)*10);
> > >  int pos =3D atoi(buf)+10;
> >
> > >  wxMessageBox(buf);
> > >  inFile.seekg(-pos, ios::end);
> >
> > >  csdText =3D "";
> > >  while(!inFile.eof()){
> > >        getline(inFile, str);
> > >        csdText =3D csdText+str;
> > >    }
> >
> > >   wxMessageBox(csdText.c_str());
> >
> > > I've also tried with wxFile but I didn't have any joy with that
> > > either. As a last resort I tried a straightforward C implementation
> > > but that also fails with odd results. Can anyone see what the problem
> > > might be, hopefully it is something silly I am overlooking. Please let
> > > me know if you need any further info. I'm using wxWidgets 2.8. Cheers,
> >
> > > Rory.
> >
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>
> Ok, I'm now successfully opening the file using an ifstream in
> ios::binary mode. Now the program does not hang but I still get
> rubbish in my display boxes. When I check the same input file with
> another non-gui application it displays the end of the file without
> any problems so I know there are characters at the end of the binary
> file. Any other ideas?
>

Set aside wx for now and write a small program to read your file and display
your desired results with cout.  When you get that working, and still have
difficulties with the wx implementation, then it will be appropriate to ask
questions about how to accomplish things in wx.

Bob
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