How can I use "mexPrintf" for simulation and "printf" for code generation in a MATLAB Function Block using coder.ceval?

I am using a MATLAB Function block in my Simulink model. My MATLAB function calls a custom C functions using "coder.ceval". I want to use "mexPrintf" in my C function during simulation but the standard C "printf" when building the model. How can I do this?

Answer 1

[MathWorks Support Team]

You can use the "MATLAB_MEX_FILE" C preprocessor macro in your custom C code to determine whether you are compiling for a MEX target. For example, you can use this macro to define a custom "printOutput" function:

#include <stdio.h>
#include <stdlib.h>

#ifdef MATLAB_MEX_FILE
#include "mex.h"
#endif

void printOutput(const char* str);

#ifdef MATLAB_MEX_FILE
// Use the mexPrintf function
void printOutput(const char* str) {
    mexPrintf(str);
}
#else
// Use the standard C printf function
void printOutput(const char* str) {
    printf(str);
}
#endif

This function is defined to call "mexPrintf" when compiled for a MEX and "printf" otherwise.