Hexdump reverse command

Question

The hexdump command converts any file to hex values.

But what if I have hex values and I want to reverse the process, is this possible?

Answer 1

If you have only a hexdump generated with hexdump you can use the following command

sed -E 's/ /: /;s/ (..)(..)/ \2\1/g;$d' dump | xxd -r

The sed part converts hexdump's format into xxd's format, at least so far that xxd -r works.

Known Bugs (see comment section)

• A trailing null byte is added if the original file was of odd length (e.g. 1, 3, 5, 7, ..., byte long).
• Repeating sections of the original file are not restored correctly if they were hexdumped using a *.