From:	Xavier Leroy <Xavier DOT Leroy AT inria DOT fr>
Subject:	Polling for ctrl-C
To:	djgpp AT sun DOT soe DOT clarkson DOT edu
Date:	Tue, 18 Aug 92 12:30:41 MET DST
Reply-To:	Xavier DOT Leroy AT inria DOT fr

I have ported an interactive program from Unix to the PC, using DJGPP.
The program needs to trap keyboard interrupts. The Unix version just
sets up a signal handler for SIGINT. As far as I know, this is not
implemented by the DJGPP library. I can understand that it's pretty
hard to generate an asynchronous interrupt from the DOS side, and have
it execute some 386 protected-mode code.

But the fact is I do not need asynchronous interrupts: for various
reasons, the program I'm porting cannot be interrupted at any time, so
the signal handler just sets a global flag, and the main program
periodically polls this flag.

It seems to me that it would not be very hard to implement this
behavior in GO32: the ctrl-C and ctrl-break handlers would set a flag,
and the program running in protected mode could would poll this flag,
either directly, or through a software interrupt.

My question is: has anybody experienced with a similar scheme? Any
hint on how to implement this ctrl-C handling in GO32 is most welcome.

Thanks for your help,

- Xavier Leroy

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