Path: utzoo!attcan!uunet!cs.utexas.edu!rice!husc6!lange!bochner
From: bochner@lange.harvard.EDU (Harry Bochner)
Newsgroups: comp.databases
Subject: Re: Informix 4GL and Vermont Views or Cscape ??
Message-ID: <4539@husc6.harvard.edu>
Date: 29 Oct 90 19:57:39 GMT
References: <993@lafayet.UUCP>
Sender: news@husc6.harvard.edu
Reply-To: bochner@lange.harvard.EDU (Harry Bochner)
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Organization: Aiken Computation Laboratory, Harvard University
Lines: 26

In article <993@lafayet.UUCP>, rob@lafayet.UUCP (Rob Freyder) writes:
 > I am interested in enhancing the limited screen interface of Informix with
 > either Vermont Views, Cscape or another C-based screen handler.
 > Any comments ?

I haven't tried to do anything like this: I try to minimize the use of C code.
But here are two problems that come to mind:
1) While you could do your own field input and output pretty simply,
duplicating
   the functionality of the CONSTRUCT statement (for Query-By-Example) is
   considerably harder. This could be a hassle unless you don't need the
   functionality in your applications. (Or unless your screen handler package
   provides similar functionality.)
2) In the versions I've used (I _still_ haven't received version 4.0 of
4GL :-(! )
   the behavior of INFORMIX's interrupt handling is sensitive to whether
it thinks
   you're waiting for input. If you read directly from the terminal using C
   functions, the INFORMIX code doesn't know that you're waiting for input, and
   you can get hung.
   This problem led me to rewrite an interface that had been using C getchar to
   use 4GL exclusively. A back door solution is possible, but liable to
   breakage ...

Harry Bochner
bochner@das.harvard.edu