Ascii/Hex convert in bash

Question

I\'m now doing it this way:

[root@~]# echo Aa|hexdump -v
0000000 6141 000a                              
0000003
[root@~]# echo -e \"\\x41\\x41\\x41\\x41\"
A         


        

Answer 1

Finally got the correct thing

echo "Hello, world!" | tr -d '\n' | xxd -ps -c 200