Hi all, I'm revisiting D after some years. I'd like to test a code snipped from RosettaCode, which is suposed to check a key press, as follows:

extern (C) {
    void _STI_conio();
    void _STD_conio();
    int kbhit();
    int getch();
}

void main() {
    _STI_conio();
    char c;
    if (kbhit())
        c = cast(char)getch();
    _STD_conio();
}

However, I'd like to know how all these functions really work, so I'd like to know where they are declared and/or defined. Since there are that extern (C) line at the beginning of the snippet, I assume them to be c code, so my question is, is there any kinda C library refference where I can find such declarations, similar to the Phobos library refference in D? In principle, I couldn't find e.g. _sti_conio by searching on Google.

In addition, I went to try building the code above with:
ldc2 -release -Os keypress.d
but received this error message:
lld-link: error: undefined symbol: _STI_conio
>>> referenced by keypress.obj:(_Dmain)


lld-link: error: undefined symbol: _STD_conio
>>> referenced by keypress.obj:(_Dmain)

Error: linking with LLD failed

As far as I recall, such kind of error indicates a library is missing on the command line. Does anyone know what it is please?

Thanks for your help,
Cleverson

On Saturday, 23 February 2019 at 21:10:19 UTC, Cleverson Casarin Uliana wrote:
> However, I'd like to know how all these functions really work, so I'd like to know where they are declared and/or defined.

Those functions are extensions from the Digital Mars C runtime library (inspired by something Borland offered back in the day).

Only real docs for them are here: https://digitalmars.com/rtl/conio.html

The STI_conio one isn't documented, I think that is the internal initializer function, and STD_conio is the destructor function.

> lld-link: error: undefined symbol: _STD_conio
> >>> referenced by keypress.obj:(_Dmain)

Those functions are only present in the DMC library, which is only used when using `dmd` to make a 32 bit build on Windows (and even then, only if you do NOT use `-m32mscoff`).

I would suggest using different functions... like my terminal.d  <https://github.com/adamdruppe/arsd/blob/master/terminal.d>library which has similar api (see example: http://dpldocs.info/experimental-docs/arsd.terminal.html#single-key )

What do you need the program to actually do?

Hi Adam, many thanks for all informations. To answer your questions:

Em 23/02/2019 20:08, Adam D. Ruppe via Digitalmars-d-learn escreveu:
> I would suggest using different functions... like my terminal.d <https://github.com/adamdruppe/arsd/blob/master/terminal.d>library which has similar api (see example: http://dpldocs.info/experimental-docs/arsd.terminal.html#single-key )
> 
OK, do I need to install the entire arsd package? I've saved the terminal.d file on an arsd directory I've just created inside the import directory, but trying to build it gives me lots of undefined symbol errors.

Admittedly, I haven't yet learned how to deal with D packages, so maybe I should do just that.

> What do you need the program to actually do?

I want a generic function that returns what key I have pressed, including keys like the arrows, so I can for example play a sound on a given key press. If the method is portable among Windows, Linux and others, so better.

BTW, although not strictly on topic, I'd also apreciate portable functions to play and stop sounds assynchronously, similar to PlaySound on Windows...

Greetings,
Cleverson

On Sat, Feb 23, 2019 at 09:53:09PM -0300, Cleverson Casarin Uliana via Digitalmars-d-learn wrote:
> OK, do I need to install the entire arsd package? I've saved the terminal.d file on an arsd directory I've just created inside the import directory, but trying to build it gives me lots of undefined symbol errors.

You just need to pass the terminal.d file to your build too.

dmd yourfile.d terminal.d

so it knows to include it.

> I want a generic function that returns what key I have pressed, including keys like the arrows, so I can for example play a sound on a given key press. If the method is portable among Windows, Linux and others, so better.

Yeah, terminal.d can do that, I don't remember if the getch function specifically handles arrows... I think it does though, but I know for sure the other functions do (you can do a full event loop with it)

> BTW, although not strictly on topic, I'd also apreciate portable functions to play and stop sounds assynchronously, similar to PlaySound on Windows...

so i have that but i'm not happy with it and it isn't documented...

Em 24/02/2019 00:19, Adam D. Ruppe via Digitalmars-d-learn escreveu:
> You just need to pass the terminal.d file to your build too.
> 
> dmd yourfile.d terminal.d
> 
> so it knows to include it.
> 
OK, it built the executable, but it doesn't work for every key, e.g. when I try with arrow and function keys, it always returns the same symbol, so I'm unable to distinguish what key has been pressed:

Press any key to continue...
You pressed 󰁰

Changing the code page on the console doesn't help either.

I'm using the command prompt on a Windows 10 Pro system. In Powershell, it behaves the same.

Greetings,
Cleverson

On Sunday, 24 February 2019 at 12:37:21 UTC, Cleverson Casarin Uliana wrote:
> OK, it built the executable, but it doesn't work for every key, e.g. when I try with arrow and function keys, it always returns the same symbol, so I'm unable to distinguish what key has been pressed:

Those don't have printable characters associated, so they all look the same. Try writeln(cast(int) code)  - casting it to int so you can see the number - and you should see the different results.

Or even

 terminal.writeln("You pressed ", cast(KeyboardEvent.Key) ch);

might be a better demo, i should change the docs, since that will print the name of most keys!

supported key list: http://dpldocs.info/experimental-docs/arsd.terminal.KeyboardEvent.Key.html

(lowest common denominator between windows and linux)

On Sunday, 24 February 2019 at 14:34:45 UTC, Adam D. Ruppe wrote:
> supported key list:

well, obviously, plus the normal printable characters like letters, numbers, tab, space, enter... but those have char values so no need to list in an enum.

Em 24/02/2019 11:34, Adam D. Ruppe via Digitalmars-d-learn escreveu:
> Those don't have printable characters associated, so they all look the same. Try writeln(cast(int) code)  - casting it to int so you can see the number - and you should see the different results.
> 
> Or even
> 
>   terminal.writeln("You pressed ", cast(KeyboardEvent.Key) ch);
> 
Thanks much, it works great.

Greetings,
Cleverson