Using the following code, I'm able to successfully open a raw disk on my machine, but when I get the disk length I get 0 each time...
// Where "Path" is /dev/rdisk1 -- is rdisk1 versus disk1 the proper way to open a raw disk?
Device = open(Path, O_RDWR);
if (Device == -1)
{
throw xException("Error opening device");
}
And getting size with both of these methods returns 0:
struct stat st;
if (stat(Path, &st) == 0)
_Length = st.st_size;
/
_Length = (INT64)lseek(Device, 0, SEEK_END);
lseek(Device, 0, SEEK_SET);
I'm not totally familiar with programming on non-Windows platforms, so please forgive anything that seems odd. My questions here are:
The disk in question is an unformatted disk, but for those wanting the info from Disk Utility (with non-important stuff removed):
Name : ST920217 AS Media
Type : Disk
Partition Map Scheme : Unformatted
Disk Identifier : disk1
Media Name : ST920217 AS Media
Media Type : Generic
Writable : Yes
Total Capacity : 20 GB (20,003,880,960 Bytes)
Disk Number : 1
Partition Number : 0
After a little bit of searching through ioctl
request codes, I found something that actually works.
#include <sys/disk.h>
#include <sys/ioctl.h>
#include <fcntl.h>
int main()
{
// Open disk
uint32_t dev = open("/dev/disk1", O_RDONLY);
if (dev == -1) {
perror("Failed to open disk");
return -1;
}
uint64_t sector_count = 0;
// Query the number of sectors on the disk
ioctl(dev, DKIOCGETBLOCKCOUNT, §or_count);
uint32_t sector_size = 0;
// Query the size of each sector
ioctl(dev, DKIOCGETBLOCKSIZE, §or_size);
uint64_t disk_size = sector_count * sector_size;
printf("%ld", disk_size);
return 0;
}
Something like that should do the trick. I just copied the code I had into that, so I'm not sure if it would compile alright but it should.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With