In this post I’ll mention how to edit binary files using vi and the utility xxd that is a part of vi.

vi in hex mode

Use the xxd command by typing

:%!xxd

Edit hex data. Quit hex mode with

:%!xxd -r

Using xxd command

You can use the xxd command outside vi. If you have an existing binary file, you can convert it to hex

You can then edit the hex and convert it back to binary

One nice little thing that xxd does is to produce a C static array definition, very convenient for embedding resource files

xxd -i file.bin