Question

On most servers running in console mode, the admin is allowed to type in commands while the server is also outputting text like player deaths, etc.

I was just wondering how to replicate this effect. I have searched all over the place and don’t even have the slightest idea on how it’s done.

Answer 1

You need to learn about threads.

All programs have at least a thread, but most console applications only have one. This way, a program can only do one thing at a time.

Imagine a program with two threads as two programs that work together towards a goal.

You can create one thread that does the computing, one that prints all the output and one that keeps reading data from the keyboard. This will create a program that can write and read at the same time.

Also, keep in mind that you need to use a multi-processor machine in order for threads to offer true parallelism to your program.

Here is a ruby example that can read and write data from/to the console at the same time:

a = Thread.new do
  while true do
    puts "Hi There!"
    sleep(1)
  end
end

b = Thread.new do
  while true do
    puts gets.strip+"!"
  end
end
a.join
b.join