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Function RTFGetDiskInfoEx

RTFGetDiskInfoEx returns information about a logical drive:

int RTFGetDiskInfoEx(const char *  DriveName, 
                     RTFDiskInfo * DiskInfo, 
                     int           Flags);

Parameters

DriveName

Must be a valid file name, e.g., a root directory name. Only the drive information (possibly the current default drive) is determined.

DiskInfo

Must point to a structure RTFDiskInfo declared in Rtfiles.h:

typedef struct { 
   char             Label[16]; 
   char             DriveLetter; 
   char             Reserved[1]; 
   WORD             DeviceFlags; 
   DWORD            SerialNumber; 
   RTFSector        FirstPhysicalSector; 
   UINT             FATType; 
   UINT             FATCount; 
   UINT             MaxDirEntries; 
   UINT             BytesPerSector; 
   UINT             SectorsPerCluster; 
   DWORD            TotalClusters; 
   DWORD            BadClusters; 
   DWORD            FreeClusters; 
   DWORD            Files; 
   DWORD            FileChains; 
   DWORD            FreeChains; 
   DWORD            LargestFreeChain; 
} RTFDiskInfo;

Flags

Can be any combination of:

return value

If the function succeeds, the return value is the Flags value corresponding to the returned information, or a negative error code on failure.

RTFGetDiskInfoEx will complete significantly faster if no FAT scan is necessary. On large FAT-32 volumes, a complete FAT scan can take up to about one minute. When the FAT has been scanned, the number of free clusters is cached (on disk for FAT-32 and in RAM for all disk formats), allowing subsequent calls with RTF_DI_FREE_SPACE to return much faster.

On ISO 9660 and exFAT volumes, flag RTF_DI_FAT_STATISTICS is not supported. If it is nevertheless specified, the function's return value will have it unset.

The various fields of structure RTFDiskInfo are:

Fields FileChains and FreeChains are good indicators for the degree of fragmentation of the volume; the example program RTFCmd defines a Fragmentation Percentage as follows: if all files and all free clusters each reside in single cluster chains (the ideal case), the fragmentation is 0%. If the average number of file chains per file is 2 (where free space is counted as one file), fragmentation is 100%. Thus, the fragmentation percentage can be calculated as follows:

100 * (FileChains + FreeChains - (Files+1)) / (Files+1)

Function RTFResetDisk

Function RTFGetPartitionInfo