CreateFile function C++

[tootypegs]

Hi i have the follwoing code but i am experiancing a lot of problems. I am to read a specific number of bytes (Size_of_the_file) from a fileand store them in a newly created file (OUTPUT_FILE).

I seem to be experiancing a number of errors regarding the use of my own variable for file paths in the CreateFile and WriteFile functions and the buffer.


can anyone see where ive gone wrong?

// Creating a file. OUTPUT_FILE contains a string for the path and file name
HANDLE FileCreate;
FileCreate = CreateFile("OUTPUT_FILE", GENERIC_WRITE, 0, NULL,
CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);


char buffer[Size_of_the_file];       //buffer set to size of variable 'Size_of_the_file'

Reading_file.seekg (start_byte,std::ios::beg) ;  //positiong the ReadFile funstion at the correct place in the file to start

Reading_file = ReadFile("C:\\temp\\usbimage2.txt", &buffer, nBytesToRead, Size_of_the_file, NULL) ;  // Reading file

// Check for end of buffer. If complete write to OUTPUT_FILE 
if (Reading_file &&  nBytesRead == 0, ) 
{ 

WriteFile(OUTPUT_FILE, buffer, nBytesToRead, numBytesWritten)

}

thanks

[dargueta]

You're using CreateFile to open a file called "OUTPUT_FILE" instead of using the contents of OUTPUT_FILE as the file name. Just get rid of the quotes in the third line and you'll be fine.

[dargueta]

I also spotted several other problems:

(1) You're destroying the file handle by setting the read to the return value of ReadFile.

Reading_file = ReadFile("C:\\temp\\usbimage2.txt", &buffer, nBytesToRead, Size_of_the_file, NULL) ;

//should be
BOOL bSuccess = FALSE;
bSuccess = ReadFile(Reading_file,&buffer, Size_of_the_file, &nBytesToRead,  NULL) ;

(2) WriteFile takes the file handle as the first parameter, not the file path:

WriteFile(OUTPUT_FILE,&buffer, nBytesToRead, numBytesWritten)

//should be
WriteFile(FileCreate,&buffer,nBytesToRead,&numBytesWritten);