Minimale Simulink S-Function, die einen String als Parameter annimmt

#define S_FUNCTION_NAME  string_param_sfunc
#define S_FUNCTION_LEVEL 2

#include "simstruc.h"

// Function: mdlInitializeSizes ===============================================
// Abstract:
//   Setup sizes of the various vectors.
static void mdlInitializeSizes(SimStruct *S)
{
    // One parameter: String
    ssSetNumSFcnParams(S, 1);
}

#define MDL_START
static void mdlStart(SimStruct *S)
{
    // Extract string parameter
    const mxArray *param = ssGetSFcnParam(S, 0);
    if(!mxIsChar(param)) {
        ssSetErrorStatus(S, "Parameter is not a string!");
        return;
    }
    const char* pCharArray = mxArrayToString(param);

    printf("Extracted string parameter '%s'\n", pCharArray);

    mxFree((void*)pCharArray);
}

// Function: mdlInitializeSampleTimes =========================================
// Abstract:
//    Initialize the sample times to be 1ms (1kHz)
static void mdlInitializeSampleTimes(SimStruct *S)
{
    // For an example what to add here, see https://techoverflow.net/2024/10/20/matlab-level-2-s-function-example-sine-wave-continous-output/
}

// Function: mdlOutputs =======================================================
// Abstract:
//      Calculate the sine wave output based on the simulation time.
static void mdlOutputs(SimStruct *S, int_T tid)
{
    // For an example what to add here, see https://techoverflow.net/2024/10/20/matlab-level-2-s-function-example-sine-wave-continous-output/
}

// Function: mdlTerminate =====================================================
// Abstract:
//    This function is called at the end of simulation for cleanup.
static void mdlTerminate(SimStruct *S)
{
    // No cleanup required for this example
}

// Required S-function trailer
#ifdef MATLAB_MEX_FILE
#include "simulink.c"   // MEX-file interface mechanism
#else
#include "cg_sfun.h"    // Code generation interface
#endif

mex -g string_param_sfunc.cpp CXXFLAGS="-std=gnu++17 -fPIC"