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specifics. All file input and output in Windows involves a small set of Win32 API functions. The most important of these functions is CreateFile(), which looks like this: HANDLE CreateFile( LPCTSTR szFileName, DWORD dwDesiredAccess, DWORD dwShareMode, LPSECURITY_ATTRIBUTES pSecurityAttributes, DWORD dwCreationDisposition, DWORD dwFlagsAndAttributes, HANDLE hTemplateFile); The CreateFile() function is important because it is used to both open and close files. Although it takes quite a few arguments, not all of them apply to basic reading and writing; you don’t need to worry about some of the arguments unless you’re performing more advanced file input and output. Knowing this, I want to point out the arguments that are relevant to reading and writing high scores. The first argument, szFileName, is used to provide the name of the file to be created or opened. The second argument, dwDesiredAccess, determines what you want to do with the file, such as read from or write to it. The fifth argument, dwCreationDisposition, determines whether you want to open an existing file or create a new file. And finally, the sixth argument, dwFlagsAndAttributes, allows you to control various other aspects of opening or creating a file, such as whether you want to limit access to read only. Rather than have you memorize the arguments to the CreateFile() function, I’d rather just show you how to use it to open and create files. Following is an example of using the CreateFile() function to create a new file ready for writing: HANDLE hFile = CreateFile(TEXT(”HiScores.dat”), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL); In this example, the new file is called HiScores.dat, and it is created and ready to be written to using the file handle returned from the CreateFile() function. The hFile handle is what you’ll use with a write function later to actually write data to the file. For now, let’s take a quick look at how you open a file for reading: HANDLE hFile = CreateFile(TEXT(”HiScores.dat”), GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_READONLY, NULL); As you can see, the CreateFile() function is called in a similar manner as it is called for writing, with a few small changes. The second argument indicates that this is a read operation, whereas the fifth argument indicates that an existing file should be opened, as opposed to creating a new one. Finally, the sixth argument specifies that the file is read-only, which prevents you from writing to it using the provided file handle even if you wanted to. Now that you have a file handle that can be used for reading or writing, depending on how you called the CreateFile() function, you’re ready to find out how to write data to a file and then read it back. The Win32 API function used to write data to a file is called WriteFile(), and looks like this: BOOL WriteFile( HANDLE hFile, LPCVOID pBuffer, DWORD dwNumberOfBytesToWrite, LPDWORD pNumberOfBytesWritten, LPOVERLAPPED pOverlapped); As with the CreateFile() function, not every argument to WriteFile() is critical for our purposes. You obviously need to provide the file handle in the first argument, as well as a data buffer from which the data is written. It’s also important to specify the number of bytes to write, as well as a pointer to a DWORD that is to receive the number of bytes actually written. The last argument is the one that you don’t need to worry about. To show you how easy it is to use the WriteFile() function, following is code to write a five-digit high score to a file: DWORD dwBytesWritten; WriteFile(hFile, &cData, 5, &dwBytesWritten, NULL); This code assumes that the high score has already been converted from an integer into a five-character string that is stored in the cData variable. Notice that the number of bytes to write is specified as 5, which makes sense considering that the score consists of five digits. Reading from a file is similar to writing to a file, except that it involves the ReadFile()

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