Question

i have a FAT16 image and i would like to copy the data stored at a specific memory location in this image in C.

If opening the myfat16.img file with hexedit gives

0000A320   44 54 FC 0C  19 85 13 E9  F6 D5 20 7F  56 24 EB A7  DC 2F 54 7A  20 10 9F 80  54 45 BB AE  E9 C2 6E 08  08 4F 01 11  16 EF 1B A7  1E 00 00 01  05 3B F0 A8  DT........ .V$.../Tz ...TE....n..O...........;..

how can I access say 0xA322?

Is the only way to open it with open() and then count the bytes until this address?

Thank you

Answer 1

Using the C standard library open with fopen and go straight to the address of your interest using fseek, and then fread or whatever reading function is most convenient to you.

If you instead have to use the POSIX syscalls directly you can use respectively open, lseek and read.