Here is a very simple version of the program I'm working on. Is there a way to write is_any_key_pressed() that doesn't block, doesn't require the Enter key, and doesn't require dragging in any complex libraries or dealing with low-level stuff like ioctl()? Is there nothing in Phobos that provides the needed functionality?

I won't go into the details, but I tried threading, putting the getchar() in a separate thread that sets a global bool g_keypressed variable. It was a disaster. Maybe there's a right way to use threading? I am not talented at threads.

import core.thread;
import core.time;
import std.stdio;
import std.conv;


void light_on() {
    write("on "); stdout.flush;
}
void light_off() {
    write("off "); stdout.flush;
}

void wait()  {
    Duration dur = dur!("seconds")( to!int(1) );
    Thread.sleep(dur);
}


bool is_any_key_pressed()  {
    getchar();  // nope, requires Enter key to be pressed, and is blocking
    return true;
}

void main(string[] args)
{

    while (true)  {
        light_on();
        wait();
        light_off();
        wait();

        if (is_any_key_pressed())  {
            break;
        }
    }
}

On Friday, 3 March 2023 at 03:38:56 UTC, Daren Scot Wilson wrote:

See this SO thread:https://stackoverflow.com/q/1798511

Essentially the os/terminal is buffering your input and that needs to be configured. getChar just reads from what's in stdin.