sudo -iu yy echo 'three   spaces'

/bin/bash -c 'echo three   spaces'

/bin/bash -c 'bash -c cat << "EOF"\012script-content\012EOF\012'

ps awx|grep $$

printf 'cat > ... << ... n ...' | sudo -iu yy

f=`mktemp`
printf 'command' > "$f"
chmod +r "$f"
sudo -iu yy "$f"
rm "$f"