Direct access to hard disk with no FS from C program on Linux

Question

I want to access the whole hard disk directly from a C program. There\'s no FS on it and never\'s gonna be one.

I just want to open /dev/sda (for example) and do I

Answer 1

As device files for drives (e.g. /dev/sda) are block devices, this means you can open, seek and use the file almost like a normal file.