Question

I have been working on an S-function for matlab in c.But the following code is crashing.My basics in c is very poor 🙂

//
static double a=0;
//

static void mdlOutputs(SimStruct *S, int_T tid)
{   
    const real_T    *u    = ssGetInputPortRealSignal(S,0);
    a=*u;   //this line creates the problem

}
//

Answer 1

The documentation doesn’t say that the return can be anything else than a pointer, but as commenters have pointed out you should check it for being NULL before de-referencing.