dev-cpp-users

AW: AW: [Dev-C++] reading a binary file

[Christian W. <Chr...@vo...>]

Hi  Carlos ,  
 
 
sorry,  but i send the wrong snipped (one of the trys)...
 
If I execute it as follows, it crashes...
 
Any idea ? 
  

  


#include "stdio.h" 
#include "fstream.h" 
#include "windows.h" 
  


int main(int argc, char* argv[]) 
{ 
  BYTE  * buffer; 
 int nRead = 0; 


 ifstream *fb = new ifstream; 
 fb->open("c:\\out.cal"); 


 if(fb->fail() != 0)printf("Cant opne\n"); 


 fb->seekg(0); 


 while (!fb->eof()) 
 { 
  fb->read(buffer, 2048); 
  nRead = nRead + 2048; 
  printf("%i\n", nRead); 
 }; 


 getchar(); 
 return 0; 
} 
  


If I execute this I get an acces voilation after the read function ... 
  


Does any one have an idea ? 
  


Kind r 
  


Christian 


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Re: AW: AW: [Dev-C++] reading a binary file

[Per W. <pw...@ia...>]

Make the following changes, and it will work.

A pointer is just that. A pointer to a block of memory. To use it, you
also must make the pointer point to some available memory. An
unininitalized pointer may point anywhere inside the computer, thereby
resulting in a crash when the program tries to follow the pointer for
either reading or writing.

Cheers

/Per Westermark

EMA System        email: pw...@ia...
Per Westermark    web: http://iapetus.neab.net
Vargvaegen 174B   phone: +46 8 410 17 198
S-906 42 Umeaa
Sweden


On Thu, 5 Sep 2002, Christian Wallukat wrote:

> Hi  Carlos ,  
>  
>  
> sorry,  but i send the wrong snipped (one of the trys)...
>  
> If I execute it as follows, it crashes...
>  
> Any idea ? 
>   
> 
>   
> 
> 
> #include "stdio.h" 
> #include "fstream.h" 
> #include "windows.h" 
>   
> 
> 
> int main(int argc, char* argv[]) 
> { 
>   BYTE  * buffer; 
>  int nRead = 0; 
> 
> 
   buffer = new BYTE[2048];
>  ifstream *fb = new ifstream; 
>  fb->open("c:\\out.cal"); 
> 
> 
>  if(fb->fail() != 0)printf("Cant opne\n"); 
> 
> 
>  fb->seekg(0); 
> 
> 
>  while (!fb->eof()) 
>  { 
>   fb->read(buffer, 2048); 
>   nRead = nRead + 2048; 
>   printf("%i\n", nRead); 
>  }; 
    delete[] buffer;
> 
> 
>  getchar(); 
>  return 0; 
> } 
>   
> 
> 
> If I execute this I get an acces voilation after the read function ... 
>   
> 
> 
> Does any one have an idea ? 
>   
> 
> 
> Kind r 
>   
> 
> 
> Christian 
> 
> 
> ------------------------------------------------------- 
> This sf.net email is sponsored by: OSDN - Tired of that same old 
> cell phone?  Get a new here for FREE! 
> https://www.inphonic.com/r.asp?r=sourceforge1
> <https://www.inphonic.com/r.asp?r=sourceforge1&refcode1=vs3390>
> &refcode1=vs3390 
> _______________________________________________ 
> Dev-cpp-users mailing list 
> Dev...@li... 
> TO UNSUBSCRIBE: http://www.noicys.cjb.net/devcpp/ub.htm
> <http://www.noicys.cjb.net/devcpp/ub.htm>  
> https://lists.sourceforge.net/lists/listinfo/dev-cpp-users
> <https://lists.sourceforge.net/lists/listinfo/dev-cpp-users> 
> 
> 
> 
> -------------------------------------------------------
> This sf.net email is sponsored by: OSDN - Tired of that same old
> cell phone?  Get a new here for FREE!
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> 

Re: AW: [Dev-C++] reading a binary file

[Abhijit S. <mu...@gm...>]

> Hi  Carlos ,
>
>
> sorry,  but i send the wrong snipped (one of the trys)...
>
> If I execute it as follows, it crashes...
>
> Any idea ?
>
>
>
>
>
> #include "stdio.h"
> #include "fstream.h"
> #include "windows.h"
>
>
>
> int main(int argc, char* argv[])
> {
>   BYTE  * buffer;
>  int nRead = 0;
>
>
>  ifstream *fb = new ifstream;
>  fb->open("c:\\out.cal");
>
>
>  if(fb->fail() != 0)printf("Cant opne\n");
>
>
>  fb->seekg(0);
>
>
>  while (!fb->eof())
>  {
>   fb->read(buffer, 2048);
>   nRead = nRead + 2048;
>   printf("%i\n", nRead);
>  };
>
>
>  getchar();
>  return 0;
> }
>
>
>
> If I execute this I get an acces voilation after the read function ...
>
>
>
> Does any one have an idea ?

Greets, Christian.

The problem is that you haven't allocated memory for the buffer. You say
char *buffer. How big should it be? The compiler has no idea. Replace it
with char buffer[2048] or, better yet, allocate it on-the-fly using `new'.

___________________________________________________________

Abhijit Shylanath

E-mail:   mu...@gm... || ibr...@bi...
Web-site: http://mudeth.tripod.com/