[open-cobol-list] User interaction preference.

[John R. Culleton]

Most modern business programming starts out with user
interaction. In the old days an order was received and it went to
keypunch for preparation of cards. Then the process was from then
on batch. That was yesterday.

In some of today's world at least the order is entered online and
iinteracts with the customer file, the inventory file etc. in
more or less real time. 

So we need an on line interactive face for whatever language we
choose. Let's assume right now Open Cobol. We can either have a
one-language system or a two language system. For the
one-language solution we have the SCREEN SECTION or the
positioned ACCEPT and DISPLAY statements as in e.g., Ryan McFarland or many
other variants. At this point Open Cobol doesn't provide either
(or did I miss something?) And even the SCREEN SECTION doesn't do
all that needs to be done, such as radio button selection. 

The two (or more) language solution offers many choices. Here are
some I am considering, based mainly on previous knowledge of
the languages:
1. Tcl/Tk
2. HTML
3. Perl/Tk
etc.

At first blush Tcl/Tk seems to have all the features needed. But
it wants to be on top, and not a called program. And passing data
back and forth would be through files accessed by both languages. It
might be necessary to establish a small work file and reread it
with each action by the user, passing information back and forth.
Not wonderful. Or messaging could perhaps be done. Where is the
COMMUNICATIONS SECTION now when we finally (after all these
decades) need one? 

HTML has of couse that kookie cgi interface with messages sent
back and forth. But it is possible to have what looks like a
single interactive program at work using said cgi interface.

To get down to cases, what facilities do we have right now for
communicating between Open Cobol and other programing languages?
And which of the many interactive languages offers the most hope?
Waht exactly is the syntax for calling an external program such
as a Tcl script? Can we use Open Cobol as a cgi program? Is
anyone actually doing it? 

I use Linux. 
 
-- 
John Culleton