C++, how to modify program under execution with new arguments

Question

The original code i posted has been edited, as it seems it caused confusion. I know it was wrong but i only wanted to use it as an example. Code i want to work with is this one:

https://github.com/SFML/SFML/wiki/Source:-AnimatedSprite

You can just focus on this part:

while (window.isOpen())
    {
        sf::Event event;
        while (window.pollEvent(event))
        {
            if (event.type == sf::Event::Closed)
                window.close();
            if (event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Escape)
                window.close();
        }

        sf::Time frameTime = frameClock.restart();

        // if a key was pressed set the correct animation and move correctly
        sf::Vector2f movement(0.f, 0.f);
        if (sf::Keyboard::isKeyPressed(sf::Keyboard::Up))
        {
            currentAnimation = &walkingAnimationUp;
            movement.y -= speed;
            noKeyWasPressed = false;
        }
        if (sf::Keyboard::isKeyPressed(sf::Keyboard::Down))
        {
            currentAnimation = &walkingAnimationDown;
            movement.y += speed;
            noKeyWasPressed = false;
        }

Let´s assume that instead of

 if (sf::Keyboard::isKeyPressed(sf::Keyboard::Up))

i want this program to act from parameters received from outside this code.

This would be the scheme i want to follow:

From my C++ code (let´s call it Origin) i call this programme (lets call it AnimatedSprite.exe) with this command:

 ShellExecute(NULL,NULL,"C:\\AnimatedSprite.exe",NULL ,NULL,SW_SHOWDEFAULT);

This will open the AnimatedSprite.exe without sending any command.

Now i want to keep it open and send him commands, like

ShellExecute(NULL,NULL,"C:\\Try.exe",MyCommandLetter.c_str() ,NULL,SW_SHOWDEFAULT);

So that when my already opened AnimatedSprite.exe receives "MyCommandLetter" as argv (yes, i know i have to declare argc and argv in main, i have to modify the original code)

it does something like:

if (argv[1]=='a')
{
currentAnimation = &walkingAnimationUp;
                movement.y -= speed;
               noKeyWasPressed = false;
}

Hope it got more clear.

It does not matter if i have to use other function which is not ShellExecute, as long as i can understand how it works (with this example it would be OK).

Thanks in advance.

Please post real code that you actually tried to compile, execute, and verify the correct results; instead of fantasy code. — Sam Varshavchik, Sep 20 '16 at 10:56
(1) The code, as you have supplied it, would not compile, let alone run and produce the behaviour you describe. (2) Once any program completes execution, there is no way to execute it again without launching it again. — Peter, Sep 20 '16 at 11:19

score 0 · Answer 1 · answered Sep 20 '16 at 11:39

Ok, as I understand the question, you want the called program react on multiple arguments. In that case you should build your main not as single "if else" statement, but rather a loop over arguments with "switch case" statement, processing all given arguments. Look for example here

C++, how to modify program under execution with new arguments

1 Answers1