/*
As stated in mount.h in /usr/src/include/sys/, 
the struct fsid is unique per filesystem on a 
single machine.

typedef struct fsid { 
int32_t val[2]; 
} fsid_t; /* filesystem id type */

 File identifier.
 These are unique per filesystem on a single machine.

struct fid {
        u_short         fid_len;                /* length of data in bytes */
        u_short         fid_reserved;           /* force longword alignment */
        char            fid_data[MAXFIDSZ];     /* data (var)
};
*/
/*
For windows, you can get the hard drive's
serial nuimber form the registry at:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\IDE\ 

In linux, you can use a tool called hdparm.
You can also use cookfp() a tool which will
get a hash value of a file and use it on a
unique file to linux systems (/etc/passwd 
comes to mind).
*/


#include <stdio.h>
#include <sys/mount.h>
#define MAXFIDSZ        16

int main (int argc, const char * argv[])
{

   struct statfs tStats;
   printf("Filesystem ID for BSD: %d\r\n", tStats.f_fsid);
   return 0;
}