I'm using the command printf of bash on Ubuntu under WSL.

I'm trying to use this documented syntax

\xHH byte with hexadecimal value HH (1 to 2 digits)

This works for printf "\x0A" (carriage return) and many other values.

But does not work for printf "\xFF" or printf "\xFE" which I want to use to inject a BOM Utf-16 prefix before piping the content of a Utf-16 file (but without bom) to some treatment.

For this values (past 0xF8 included), I get the error:

-bash: printf: write error: Input/output error