ReadingWriting Hard Disk Sectors

On 1 Jun 2005 15:38:55 -0700, Kjell staggered into the Black Sun and said:

"man 2 write" says that the write(int fd, const void *buf, sizet count) syscall writes count bytes from buffer buf to file descriptor fd. The position of the bytes you write can be controlled by the lseek() system call or the fseeko() C library function, naturally. I *think* that all you need to do is to translate the C-H-S address into a linear byte position and seek to that position before you write.

You may wish to test this out by mounting a scratch disk, writing to specific C-H-S addresses with something (another utility?), then seek()ing to those C-H-S addresses and making sure you can read the data you wrote back.

One more thing: I thought that SCSI disks always used LBA, not CHS. ICBW though.

If all you need to do is seek to a specific place before reading or writing, then I don't think you'll have to mess with anything other than fseeko() or lseek(). Anyway, HTH,

-- Matt GThere is no Darkness in Eternity-But only Light too dim for us to see Brainbench MVP for Linux Admin mail: TRAP + SPAN don't belong