asked on

Displaying results from GetDiskFreeSpaceEx()

Hey guys, I'm using GetDiskFreeSpaceEx() to get the disk size and free space of whatever disk I select. The function works perfectly and returns the correct size of the disk in bytes.

The problem I'm running into is that I want to display the data as kilobytes, megabytes, or gigabytes. With 32-bit integers, I would just type cast them to double and divide by 1024 the necessary number of times. But since GetDiskFreeSpaceEx() uses unsigned 64-bit integers, I get an error trying to type cast to double. I tried doing a normal divide to get the integer portion of the result and then using the modulus operator (%) to get the remainder... but modulus doesn't seem to work correctly with such large numbers (and apparently chops of any leading zeros).

Is there a way to convert unsigned 64-bit integers to double? If not, how can I display the bytes as KB, MB, or GB?

I'm using MS Visual C++ 6.0 on Windows NT.

Thanks

ASKER CERTIFIED SOLUTION

mnashadka

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

ASKER

Thanks mnashadka, that worked. I don't like type casting unsigned integers to signed ones due to possible corruption of data, but in this case I don't believe I'll ever encounter a drive that goes above the limit of a signed __int64. Thanks for the help.

mnashadka

I agree with you about the signed/unsigned thing. If you only need integers, not floating point numbers, you can using the unsigned __int64 instead. I think it's called ULONGLONG or something like that. Either way, I'm glad that I could help. Good luck.

Mike