How to write a binary file using Bash?

Question

My problem is that I need to create a file with this exact bytes: 48, 00, 49, 00.

I cannot use C, perl, other scripting language (the target is an embedded

Answer 1

I don't know what's in busybox, but this might work because printf is smaller than awk.

$ printf "%c%c%c%c" 48 0 49 0 | hexdump

This is the output:

$ printf "%c" 1 | hexdump
0000000 0031