Using grep to search for hex strings in a file

Question

I have been trying all day to get this to work. Does anyone know how to get grep, or something of the like, to retrieve offsets of hex strings in a file?

I have a bu

Answer 1

grep has a -P switch allowing to use perl regexp syntax the perl regex allows to look at bytes, using \x.. syntax.

so you can look for a given hex string in a file with: grep -aP "\xdf"

but the outpt won't be very useful; indeed better do a regexp on the hexdump output;

The grep -P can be useful however to just find files matrching a given binary pattern. Or to do a binary query of a pattern that actually happens in text (see for example How to regexp CJK ideographs (in utf-8) )