LEICHTER@VENUS.YCC.YALE.EDU ("Jerry Leichter ", LEICHTER-JERRY@CS.YALE.EDU) (05/16/88)
I just hate it when a vendor tells me "it can't be done". I am trying to support a product that does not allow for a startup file. The product is fairly complex, complete with a script language (like DCL). Since there are a number of environmental variables that our users could profitably set at startup time (abbreviations, search paths, terminal type, etc.) I assumed there would be a startup file. The vendors, who develop on PRIMOS, tell me they don't have a portable startup mechanism, PRIMOS has some sort of "RESTART" work around. So I started playing with redefining SYS$INPUT, ^Y, deassigning, CONTINUE, etc. but to no avail. The terminals being used are without answerback, but I wondered--is it possible to write to the terminal typeahead buffer? Sure. All you have to do is write some kernel-mode code that finds the type- ahead buffer, synchronizes properly with the I/O system, and stuffs the characters in. Now, if you want something SUPPORTABLE, that won't require a lot of hacking and system crashes along the way, that can be guaranteed to work in later versions of VMS - well, that's another story. I've read the terminal driver manual to no avail. Can one flush the typeahead buffer and then write to it? Actually, it is possible to "prime" the input buffer - but only as part of the input operation - i.e., you'd have to change the program. This facility is used by DCL to implement multiple-line recall. But that won't help you here. If so, I could stuff the "extra" command I want executed immediately after the command to start the package: "ARC^M&RUN STARTUP". Is this too far fetched? I'm afraid so. Without more details about the particular problem, it's not easy to propose solutions. If all else fails, running the program through a controller that use a PTY driver (from DECUS or elsewhere) would provide a solution, though hardly the best one. (Waiting for the vendor to see the light might take a while.) Refusing to buy the product until it is fixed can be very illuminating! -- Jerry
R1ECGF@AKRONVM.BITNET (Doug Greenwald) (05/19/88)
We here run a Prime under Primos. If you could tell us something about what the package is, maybe someone here could help with your initialize problem. Doug.