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  • Ctrl-C Interrupt?

    From Bill Chatfield@21:1/5 to All on Sun Dec 10 19:47:12 2023
    Is there any way to have Ctrl-C interrupt a BIN program like it does a
    Basic program? I know Ctrl-Reset will do it, but that messes up the
    screen and probably other things too.

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  • From Hugh Hood@21:1/5 to Bill Chatfield on Sun Dec 10 21:10:13 2023
    On 12/10/2023 6:47 PM, Bill Chatfield wrote:
    Is there any way to have Ctrl-C interrupt a BIN program like it does
    a Basic program? I know Ctrl-Reset will do it, but that messes up
    the screen and probably other things too.


    Bill,

    Are you able to patch the particular BIN program?

    If so, I might suggest you inject a JMP somewhere in the program's main
    'run' loop to some new code you graft onto the end of the code.

    The new code would save the registers, poll the keyboard, check for a
    CTRL-C, and just BRK if a CTRL-C is found. If not, just add whatever
    code you messed up by inserting the JMP to the new code, restore the
    registers, and then JMP back to where the program was interrupted.

    Or, if the program already is polling the keyboard for some input, can
    you just re-purpose a key you don't normally need to do the same, or
    maybe JMP to a routine to add the check for CTRL-C?

    Just some thoughts. Maybe none of them are appealing.

    I'm assuming you're not using a IIgs where you can interrupt and Visit
    the Monitor.




    Hugh Hood

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  • From Bill Chatfield@21:1/5 to fadden on Mon Dec 11 10:07:42 2023
    On Sun, 10 Dec 2023 17:54:54 -0800 (PST)
    fadden <fadden@fadden.com> wrote:

    It's not a system feature; it doesn't send a signal the way a UNIX
    line discipline does.

    Is it too much to ask for an Apple II to work like UNIX? Haha :-) :-)

    I've always been frustrated by the inconsistency that you Ctrl-C a
    BASIC program but you have to Ctrl-Reset a binary program. You have to
    know what type of program is running to know what interrupt to use. I
    guess you can always use Ctrl-Reset, but that is more invasive.

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  • From Bill Chatfield@21:1/5 to Hugh Hood on Mon Dec 11 10:09:43 2023
    On Sun, 10 Dec 2023 21:10:13 -0600
    Hugh Hood <hughhood@earthlink.net> wrote:

    Just some thoughts. Maybe none of them are appealing.

    I'm assuming you're not using a IIgs where you can interrupt and
    Visit the Monitor.

    I am working on a Apple II/e/c program with the cc65 C compiler. I can
    check for Ctrl-C in various places.

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  • From Bill Chatfield@21:1/5 to I am Rob on Mon Dec 11 10:11:01 2023
    On Sun, 10 Dec 2023 20:30:01 -0800 (PST)
    I am Rob <gids.rs@sasktel.net> wrote:

    A simple method would be to just poll $C000, then place JSR's to this
    routine where you would want the keyboard to be interrupted. Say,
    after a page of text is displayed or even throughout your code at
    various places.

    Yes, I can try that. Thanks!

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  • From Oliver Schmidt@21:1/5 to All on Mon Dec 11 19:10:41 2023
    Hi Bill,

    I am working on a Apple II/e/c program with the cc65 C compiler. I can
    check for Ctrl-C in various places.

    In this case I suggest to use
    - kbhit() and cgetc() to detect the Ctrl-C
    - exit() to quit if Ctrl-C was detected
    - atexit() to run custom cleanup code

    Not directly related but there's also doesclrscrafterexit() that allows you determine if the user will be able to read output from your program after
    exit - i.e. an error message. You can call it i.e. from your atexit()
    function and call cgetc() if it returns true having the user acknowledge
    that he has read the message.

    Regards,
    Oliver

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  • From Bill Chatfield@21:1/5 to Oliver Schmidt on Mon Dec 11 15:39:07 2023
    On Mon, 11 Dec 2023 19:10:41 -0000 (UTC)
    Oliver Schmidt <ol.sc@web.de> wrote:

    In this case I suggest to use
    - kbhit() and cgetc() to detect the Ctrl-C
    - exit() to quit if Ctrl-C was detected
    - atexit() to run custom cleanup code

    Thanks! I was thinking of using an asm block to check KBD for
    characters. What you said is much better. I also forgot about atexit().
    I need to put that in now to close files. It's like the "finally" block
    of a try/catch/finally around main(). I'm a Java programmer during the
    day.

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  • From Oliver Schmidt@21:1/5 to All on Tue Dec 12 20:36:39 2023
    Hi Bill,

    Thanks!

    You're welcome :-)

    I was thinking of using an asm block to check KBD for
    characters. What you said is much better.

    I'm quite often surprised by the amount of workarounds people "find"
    although the functionality is already present in the Apple II C library.

    I also forgot about atexit().
    I need to put that in now to close files. It's like the "finally" block
    of a try/catch/finally around main(). I'm a Java programmer during the
    day.

    You don't need to do so for closing files. All still open files are closed
    by the C library exit code.

    That code is by the way also executed on Ctrl-Reset during the runtime of a cc65 C program. So the behavior on Ctrl-Reset isn't as undefined/fatal as
    you might think.

    I even had once the case where I totally ran out of memory so I couldn't
    add some quit code. Instead I simply documented Ctrl-Reset as the official
    way to quit the program ;-)

    Regards,
    Oliver

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  • From Bill Chatfield@21:1/5 to Oliver Schmidt on Tue Dec 12 23:55:06 2023
    On Tue, 12 Dec 2023 20:36:39 -0000 (UTC)
    Oliver Schmidt <ol.sc@web.de> wrote:

    You don't need to do so for closing files. All still open files are
    closed by the C library exit code.

    I am always amazed about how well cc65 implements the standard. I was
    thinking in terms of BASIC which does not do that and gets completely
    screwed up if you don't close files.

    That code is by the way also executed on Ctrl-Reset during the
    runtime of a cc65 C program. So the behavior on Ctrl-Reset isn't as undefined/fatal as you might think.

    That is very impressive. I never would have guessed that.

    I even had once the case where I totally ran out of memory so I
    couldn't add some quit code. Instead I simply documented Ctrl-Reset
    as the official way to quit the program ;-)

    :D

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