Re: DBESCWAIT

>From ilist@rmy.emory.edu Mon Apr 25 04:11:45 1994 >From: spitz@GANS2X.ana.med.uni-muenchen.de (Richard Spitz) >Message-Id: <Cot5DD.GKA@informatik.uni-muenchen.de> >Subject: DBESCWAIT >Date: Mon, 25 Apr 1994 09:08:01 GMT >Organization: Institut fuer Anaesthesiologie der Universitaet Muenchen >Sender: informix-list-owner@rmy.emory.edu >To: informix-list@rmy.emory.edu >X-Informix-List-To: eu-informix-distr@inflon.informix.com >X-Informix-List-Id: <news.6475> > >Hi, > >I am looking for information about the undocumented environment variable >DBESCWAIT. We are having problems using the cursor keys in 4GL applications >when run over the network, and I remember reading something about this >variable which might solve the problems. > >Regards, Richard >-- >+----------------------------+-------------------------------------------+ >| Dr. Richard Spitz | INTERNET: spitz@ana.med.uni-muenchen.de | >| EDV-Gruppe Anaesthesie | Tel : +49-89-7095-3421 | >| Klinikum Grosshadern | FAX : +49-89-7095-8886 | >| 81366 Munich, Germany | | >+----------------------------+-------------------------------------------+ > From the 4.12.UD1 Release Notes: ENVIRONMENT VARIABLE DBESCWT ============================ The environment variable DBESCWT has existed since Version 4.00, and can be used to control the way the Informix tools interpret the sequence of characters sent by the function and arrow keys on some types of terminals. When you press a function key, many terminal types send a sequence of characters that starts with the ESC character. Some terminals send a sequence starting with ESC when the user hits an arrow key. Informix software normally uses the ESC character as the ACCEPT key. This means that after reading an ESC character, the software has to read another character to see whether it is one of the ones that makes up a function or arrow key sequence. But it shouldn't wait indefinitely, and the delay is configurable using DBESCWT. DBESCWT is set to a value between 1 and 60, and it is the number of seconds that the software will wait after receiving the ESC (or ESCAPE) character from the keyboard before deciding that the user has hit ESC rather than having hit a function key or arrow key. When escape sequences are generated by function and arrow keys, they are normally delivered to the application faster than a touch-typist can type so that the application can make a distinction between the special keys and the user typing the characters in the escape sequence. DBESCWT was initially implemented to help customers who had very slow machines. This meant their function keys were seen as escape with a character echoed to the screen. This also occurred intermittently over a slow network. By setting this to a higher number the wait would be longer and we will understand the function key as an escape sequence. This variable should be used sparingly and only on systems with poor response times, or where the software is misinterpreting arrow key sequences. It is now documented, after a fashion. Yours, Jonathan Leffler (johnl@informix.com) #include <disclaimer.h>