Generate bytes from ASCII hexadecimal dump.
hexgen
hexgen reads hexadecimal numbers on stdin and writes bytes with values
corresponding to the numbers.
Whitespace (spaces, tabs, newlines) are simply ignored when read. Any other
character that is not a hex digit will quit hexgen with an error.
Running
echo "4865 6c6c 6f20 776f 726c 64 21 0a" | hexgen
will output Hello world!
hd(1) and xxd(1)