High Fibre Programming

Update: I have created an updated article which describes a multithreaded approach in Java Spinning command line cursor in Java

I think I must be really bored this morning, I can’t believe I’m actually blogging this, but it might be useful for someone, who knows.   Anyway, I am currently writing a program that sits and does stuff for a very long time, and I need a way to nicely indicate the program is still running and doing its stuff.   So I have created a little method that prints a spinning cursor on the command line.   The implementation would of course have to be multithreaded; one thread to do stuff, the other to spin the cursor – if there’s time I’ll update it to a more complete solution, but for now here’s the spin implementation:

public class Spin
{
    public static void main(String[] args) throws InterruptedException
    {
        String[] phases = {"|", "/", "-", "\\"};

        System.out.printf("Spinning... |");

        while (true)
        {
            for (String phase : phases)
            {
                System.out.printf("\b"+phase);
                Thread.sleep(100);
            }
        }
    }
}

And here it is in PHP.

<?php

    $phases = array("|", "/", "-", "\\");

    printf("Spinning... |");

    while (1)
    {
        foreach ($phases AS $phase)
        {
            printf('%s%s', chr(8), $phase);
            usleep(100000); // Replace this with one iteration of doing stuff
        }
    }

Of course PHP doesn’t support threading so you’d have to call each iteration of the “doing stuff” loop inside the spin loop which would mean you’d get a bit of a jumpy spinning cursor but I think most people could live with that.