sending a null character to a terminal

UNIX for Advanced & Expert Users
1

I'm testing out some ESMTP AUTH stuff, and it requires that the username and password be on the same line separated by a null character. Does anyone know how to echo the ASCII null character?

Thanks,
Alex

2

printf "\0"

3

There's no control or ALT-\d\d\d\d key combination to be able to type a null character byte?

4

control-@ is a null. But your terminal driver and shell may influence the conditions under which it will transmit a null character to the system.