Solved

open a very huge file (48 GB) in C++ or C

Posted on 2004-10-08
5
203 Views
Last Modified: 2012-08-13
I need open a very huge file and until now I could not open it!
So I need help about it.    The characteristics of my PC are: 2GB RAM, 2.99 GHz, I am compiling with Visual C++ and OS is Windowd

main()
{

  char *path1 = "C:\\Reconstruction\\quad-HIDAC_data\\Test_File.lst";
  char buffer[1024];

  fstream fin;   // object from fstream class

  fin.open(path1,ios::binary,ios::in);
 
  if(!fin.is_open())
  {
        cout << "Fail....";
        return 0;
  }
  else
  {
 
    // do somthig


     fin.close();
  }

}
0
Comment
Question by:ormale67
  • 2
5 Comments
 
LVL 86

Accepted Solution

by:
jkr earned 125 total points
ID: 12261416
A file of that size will fail because of the 32bit size limit. You'll have to use the Win32 API to access it, e.g.

#include <windows.h>

void main () {


 char *path1 = "C:\\Reconstruction\\quad-HIDAC_data\\Test_File.lst";
 char buffer[1024];
 DWORD dwRead;

 HANDLE  hFile = CreateFile ( path1, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);

 while ( 1) {

  ReadFile ( hFile, buffer, 1024, &dwRead, NULL);

  // ...
 }

 CloseHandle ( hFile);
}
0
 

Author Comment

by:ormale67
ID: 12261460


I will complie this code,

thanks !

0
 
LVL 30

Expert Comment

by:Axter
ID: 12262338
I recommend that you also use MapFile API function in addition to CreateFile API function.

That will speed up your code when reading and writing.
0
 

Author Comment

by:ormale67
ID: 12652949
I already answer this question, and this is the code that could work for open a huge file:  This example was found
with the help of Visual C++ 6.0.

/* OPEN.C: This program uses _open to open a file
 * named OPEN.C for input and a file named OPEN.OUT
 * for output. The files are then closed.
 */

#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <io.h>
#include <stdio.h>

void main( void )
{
   int fh1, fh2;

   fh1 = _open( "OPEN.C", _O_RDONLY );
   if( fh1 == -1 )
      perror( "open failed on input file" );
   else
   {
      printf( "open succeeded on input file\n" );
      _close( fh1 );
   }

   fh2 = _open( "OPEN.OUT", _O_WRONLY | _O_CREAT, _S_IREAD |
                            _S_IWRITE );
   if( fh2 == -1 )
      perror( "Open failed on output file" );
   else
   {
      printf( "Open succeeded on output file\n" );
      _close( fh2 );
   }
}
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Need some help with Microsoft Visual Studio C++ 2003 5 71
Path to  STL Map header file 1 78
Issues with C++ Class 19 105
Error creating a new C++ project in ,net 20 51
IntroductionThis article is the second in a three part article series on the Visual Studio 2008 Debugger.  It provides tips in setting and using breakpoints. If not familiar with this debugger, you can find a basic introduction in the EE article loc…
This article shows you how to optimize memory allocations in C++ using placement new. Applicable especially to usecases dealing with creation of large number of objects. A brief on problem: Lets take example problem for simplicity: - I have a G…
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will be introduced to the member functions push_back and pop_back of the vector class. The video will teach the difference between the two as well as how to use each one along with its functionality.

762 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question