Signals in OpenSCAD

Here’s the translation of the Go signals example to OpenSCAD, formatted in Markdown suitable for Hugo:

Our program demonstrates how to handle signals in OpenSCAD. While OpenSCAD doesn’t have built-in signal handling like Unix-based systems, we can simulate a similar behavior using a custom function and user input.

// Simulating signal handling in OpenSCAD

// Function to simulate signal handling
function handle_signal(signal) = 
    signal == "SIGINT" ? "interrupt" :
    signal == "SIGTERM" ? "terminate" :
    "unknown signal";

// Main program
module main() {
    echo("Awaiting signal...");
    
    // Simulate waiting for a signal
    signal = "";
    while (signal == "") {
        echo("Enter 'SIGINT' or 'SIGTERM' to simulate a signal:");
        signal = "";  // In real OpenSCAD, you would get user input here
    }
    
    // Process the received signal
    result = handle_signal(signal);
    echo(str("Received signal: ", result));
    
    echo("Exiting...");
}

// Run the main program
main();

In this OpenSCAD simulation:

1. We define a handle_signal function that mimics signal handling. It takes a string representing a signal and returns an appropriate response.

2. The main module simulates the program’s main execution:

   • It prints a message indicating it’s awaiting a signal.
   • It then enters a loop, simulating waiting for input. In a real OpenSCAD environment, you would need to provide input manually.
   • Once a signal is received (simulated by setting the signal variable), it processes the signal using the handle_signal function.
   • Finally, it prints the result and an exit message.

3. We call the main module to run the program.

To run this program:

1. Save the code in a file with a .scad extension, for example, signal_handler.scad.
2. Open the file in OpenSCAD.
3. In the console window, you would see the “Awaiting signal…” message.
4. In a real interactive environment, you would input either “SIGINT” or “SIGTERM” to simulate receiving a signal.
5. The program would then display the corresponding message and exit.

Note that this is a simulation of signal handling in OpenSCAD, which doesn’t have native support for system signals or real-time user input. In practice, OpenSCAD is primarily used for creating 3D models and doesn’t typically handle system-level operations like signal processing.