C++ Builder - Handle to OS to Iterate Through All Drives

Question

I'm using Borland C++ Builder for a project which connects to a database.

There is a configuration which does backups to a USB drive. The problem with the current approach is that the drive is manually configured by the end user and sometimes things get messed up. E.g. People move the USB drive to a different port, get a different letter and then the back up process no longer works. As a side note, we have other "better" processes for backing up to the cloud, etc., however some locations don't have internet access and aren't running on a RAID... so backing up to USB gives them a saving grace from a HD crash.

I'm hoping to do some coding to help remove this issue. I'm hoping to be able to get a handle to the OS (Windows 8/7/XP) and be able to identify the drives on the machine. Once I have those, I can then iterate through them and check for a path location (e.g. File marker, so if a the file exists, I know its the USB we supplied). Then once I have that, I can do the back up.

As a worse case scenario, I will be able to iterate through all 26 letters to test each drive. However I'm using this as a learning opportunity and hoping to get a handle to the OS so reduce the number of checks/fails I can run into. Besides, I'm curious if anyone has a better approach :)

Answer 1

I don't think there's much to be gained by trying to do something more advanced than iterating over the 26 drive letters.

Before attempting to check whether or not the marker path exists you could add a call to GetDriveType and compare the return value against DRIVE_REMOVABLE. This will make sure that your code doesn't spin up the CD/DVD drive, or hit the network in the case of a mapped share.