painless

painless is a header-only C++ library that provides an easy way to use interactive parameters in your program.

New parameters are defined with a macro call that takes an identifier (and name) for the parameter as well as a default value:

PAINLESS_PARAMETER(my_parameter, 3.14f);

The variable my_parameter can then be used as if it was a normal float value.

At runtime, painless then creates a file called /tmp/painless/my_parameter with the following content:

3.14
# Parameter 'my_parameter'
# Default value: '3.14'

In the background, it spawns a thread that watches for modifications to that file. Changes to the value will be immediately reflected in the running program.

Example

#include <painless/parameter.h>

#include <chrono>
#include <iostream>
#include <thread>

int main() {
  PAINLESS_PARAMETER(count, 10);
  PAINLESS_PARAMETER(message, "X");

  while (true) {
    // Print the 'message', 'count' times
    for (int i = 0; i < count; ++i) {
      std::cout << message;
    }
    std::cout << "\n";

    std::this_thread::sleep_for(std::chrono::milliseconds(100));
  }
}

While this program runs, the files /tmp/painless/message and /tmp/painless/count can be edited in order to interactively change the values of the message and count parameters.

Goals

painless is mainly intended for early exploratory development phases and does not aim to be a feature-complete parameter handling solution.