Hex to Binary conversion in bash

Question

I\'m trying to convert a series of bytes from hex to bin using bash. but I keep getting (seemingly random) \"(standard_in) 1: syntax error\" replies from the following code:

Answer 1

I came up with this:

printf converts to hex, xxd -r -p takes the ascii hex stream and makes it actual binary

dumping with hexdump to prove it worked...

printf "%016x" 53687091200 | xxd -r -p | hexdump -C