[ksh93-integration-discuss] about debug options in ksh

[paul.guo]

Hi, all

I have two questions about ksh, and since I am not in the alias, please
add my
email address when replying.

1. I am using ksh88, and found 'set -x' and 'set -v' do not work on
sub-functions.
Is ksh93 still like that ? Why don't allow these options in
sub-functions? 

2. If you write scripts in shell languages, you must be very careful to
prevent
the typo. shell almost does not provide any options to prevent typo. Is
is possible
to add a set option to check if variable is undefined or null and send
warning info to
user.

Thanks,

-paul