How to return pointer from C caller function?

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Ismail Mussed 2020-9-14

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评论： Ruben Galvez 2024-1-16

I'm trying to use the C caller in Simulink to call a function that returns a pointer to an array. The function definition is like this:

int *convert_to_string (int input) {
    static int arr[10];
    arr[0] = input;
    arr[1] = input + 1;
    return arr;
    }

But the C caller can't find any function that has a * in front of it. This surprised me because returning a pointer to an array is something totally routine in C. I noticed there is a "size" parameter for the output argument of the C caller block, but it isn't clear if there's a way to make that anything but 1.

How do I make the C caller find my function that returns a pointer?

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Answer 1

majety 2020-11-4

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Hi Matthew,

You could try passing in the int * arr as an input argument to the function. When you configure your C-Caller block in Simulink, you can set the arr variable as an output. Let me know if that doesn't work.

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Ruben Galvez 2024-1-16

This would be a solution if you merely wanted to modify the content of the memory region where arr is pointing to. If you want arr to point to somewhere else, you need a function that returns a pointer.

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