FILEINFOBYHANDLEBUFFER

FILEINFOBYHANDLEBUFFER is a structure used in Windows operating systems to retrieve information about a file when you have a file handle. This structure is passed to the GetFileInformationByHandle function. It contains various members that describe the file's attributes, size, and other relevant metadata.

The members of FILEINFOBYHANDLEBUFFER include a FILETIME structure for creation, access, and write times, a DWORD for volume serial number, a large integer for file size, and DWORDs for number of links and allocation size. It also includes members for the file system and a FILE_ID_128 structure to uniquely identify the file. The specific information returned can vary depending on the operating system version and the type of file handle.

Using FILEINFOBYHANDLEBUFFER and GetFileInformationByHandle is a way to query file system details directly from a valid file handle, which can be more efficient than other methods in certain scenarios. It's particularly useful when you already have an open file and need to inspect its properties without reopening the file by its path. The structure is designed to be extensible, allowing for future additions of file information fields.