I'm trying to edit a binary file directly and I know two editors, vi and hexedit. But when I open a binary file separately using them, the cotens are different. Below is what I did.
First I use "dd if=/dev/sda of=mbr bs=512 count=1" to generate the binary file, which contains the mbr data. Then I open it using "hexedit mbr", and it displays this: beginning:
00000000 EB 63 90 D0 BC 00 7C 8E C0 8E D8 BE 00 7C BF 00
00000010 06 B9 00 02 FC F3 A4 50 68 1C 06 CB FB B9 04 00
00000020 BD BE 07 80 7E 00 00 7C 0B 0F 85 0E 01 83 C5 10
ending:
000001E0 FF FF 83 FE FF FF 00 40 D6 02 00 38 2B 01 00 00
000001F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 AA
I using "vi mbr" open it and type":%!xxd", it displays this: beginning:
0000000: c3ab 63c2 90c3 90c2 bc00 7cc2 8ec3 80c2
0000010: 8ec3 98c2 be00 7cc2 bf00 06c2 b900 02c3
0000020: bcc3 b3c2 a450 681c 06c3 8bc3 bbc2 b904
ending:
00002b0: bfc3 bf00 40c3 9602 0038 2b01 0000 0000
00002c0: 0000 0000 0000 0000 0000 0000 55c2 aa0a
The hexedit displaying is what I expect in mbr. But what to say with vi displaying? Also the vi displaying seems wrong because there are more than 512 bytes.
Thank you for any explainations!
The command :%!xxd
uses the external program xxd
, so you should first try to check its output by typing:
xxd mbr
If it looks good, try opening vi in binary mode (no EOL):
vi -b mrb
then :%!xxd