Solved

Direct File manipulation

Posted on 2002-04-05
5
153 Views
Last Modified: 2010-04-02
Hello,
   I need to search directly for different records within a file in its actual location...as basically as possible.  Does anyone have any suggestions for me?
Thanks
0
Comment
Question by:pingle
  • 3
  • 2
5 Comments
 
LVL 86

Expert Comment

by:jkr
ID: 6921176
See http://support.microsoft.com/support/kb/articles/Q292/4/85.ASP ('HOWTO: Programmatically Save an HTML Page to Disk'). The scoop is:

Accomplishing this task from a Visual C++ host is very straightforward. You can use an IWebBrowser2
interface to call the QueryInterface method for the IHTMLDocument2 interface. After you obtain a pointer
to the document, then call QueryInterface for the IPersistFile interface. After you obtain this interface
pointer, you can call the save method to save the file to disk.

   HRESULT          hr    = E_FAIL;
   IDispatch*       pDisp = NULL;
   IHTMLDocument2*  pDoc  = NULL;
   
   pDisp                  = m_webOC.GetDocument();

  if(SUCCEEDED(hr = pDisp->QueryInterface(IID_IHTMLDocument2,(void**)&pDoc)))
  {
      IPersistFile*     pFile     =     NULL;
      if(SUCCEEDED(pDoc->QueryInterface(IID_IPersistFile,(void**)&pFile)))
      {
    LPCOLESTR     file = L"c:\\test1.htm";
    pFile->Save(file,TRUE);
      }
  }
0
 
LVL 86

Expert Comment

by:jkr
ID: 6921178
Ooops, sorry, wrong browser window :o)
0
 
LVL 86

Accepted Solution

by:
jkr earned 50 total points
ID: 6921188
Well, the easiest way for navigating a file is using 'fseek()':


#include <stdio.h>

void main( void )
{
   FILE *stream;
   char line[81];
   int  result;

   stream = fopen( "fseek.out", "w+" );
   if( stream == NULL )
      printf( "The file fseek.out was not opened\n" );
   else
   {
      fprintf( stream, "The fseek begins here: "
                       "This is the file 'fseek.out'.\n" );
      result = fseek( stream, 23L, SEEK_SET);
      if( result )
         perror( "Fseek failed" );
      else
      {
         printf( "File pointer is set to middle of first line.\n" );
         fgets( line, 80, stream );
         printf( "%s", line );

      }
      fclose( stream );
   }
}

0
 
LVL 30

Expert Comment

by:Axter
ID: 6921320
If you're running on a Windows platform, you can do a MapView, and get a (void*) pointer to the data in the file.
You can then use regular C++ functions to manipulation the data in the file.
0
 
LVL 30

Expert Comment

by:Axter
ID: 6921337
FYI:
You can also do MapView from unix using mmap and munmap functions.
0

Featured Post

Courses: Start Training Online With Pros, Today

Brush up on the basics or master the advanced techniques required to earn essential industry certifications, with Courses. Enroll in a course and start learning today. Training topics range from Android App Dev to the Xen Virtualization Platform.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
how to convert c++ code to Android App 3 95
IdTelnet1DataAvailable handler freezes the Application 4 74
Create a path if not exists 7 77
Safe conversion? 4 67
Often, when implementing a feature, you won't know how certain events should be handled at the point where they occur and you'd rather defer to the user of your function or class. For example, a XML parser will extract a tag from the source code, wh…
This article will show you some of the more useful Standard Template Library (STL) algorithms through the use of working examples.  You will learn about how these algorithms fit into the STL architecture, how they work with STL containers, and why t…
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 technique of using vectors in C++. The video will cover how to define a vector, store values in the vector and retrieve data from the values stored in the vector.

785 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