MATLAB: How to use “mexPrintf” for simulation and “printf” for code generation in a MATLAB Function Block using coder.ceval

codegencodermacroMATLABmatlab_mex_filemexmexprintfprintfsimulinksimulink coderstdout

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?

Best Answer

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.
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