Thread overview
Prevent console line advancing on user input
Apr 06, 2023
anonymouse
Apr 07, 2023
anonymouse
April 06, 2023
Wondering if this is possible? Ask a user at input and wait for response:

write("Is the sky blue? ");
readf!" %s\n"(response);

If the user's response is correct, I'd like to change the color of provided response to indicate it was correct then advance to the next line and ask a different question.

If the user's response is incorrect, I'd like to clear the line and repeat the question without advancing down the screen vertically.

I'm assuming it can be done by intercepting all input before the console processes them and outputting a '\r', a blank line the length of the screen, and another '\r' to get back to the beginning before reprinting the question. But I have no idea how to intercept the raw input.

Would appreciate any pointers.
Thanks
--anonymouse
April 06, 2023
On 4/6/23 4:01 AM, anonymouse wrote:
> Wondering if this is possible? Ask a user at input and wait for response:
> 
> write("Is the sky blue? ");
> readf!" %s\n"(response);
> 
> If the user's response is correct, I'd like to change the color of provided response to indicate it was correct then advance to the next line and ask a different question.
> 
> If the user's response is incorrect, I'd like to clear the line and repeat the question without advancing down the screen vertically.
> 
> I'm assuming it can be done by intercepting all input before the console processes them and outputting a '\r', a blank line the length of the screen, and another '\r' to get back to the beginning before reprinting the question. But I have no idea how to intercept the raw input.

You can't intercept raw input. It's the terminal that decides when to send you the line of text, you cannot control it via `stdin`.

You need to use a terminal-control library, such as `arsd.terminal`

https://github.com/adamdruppe/arsd/blob/master/terminal.d

-Steve
April 07, 2023
On Thursday, 6 April 2023 at 14:51:43 UTC, Steven Schveighoffer wrote:
> On 4/6/23 4:01 AM, anonymouse wrote:
>> Wondering if this is possible?
[snip]
> You need to use a terminal-control library, such as `arsd.terminal`
>
> https://github.com/adamdruppe/arsd/blob/master/terminal.d
>
> -Steve

That works perfectly. Thanks.