User Messages in C MEX Files
To print text in the MATLAB® Command Window, use the mexPrintf function as you
would a C/C++ printf function. To print error and warning information
in the Command Window, use the mexErrMsgIdAndTxt and
mexWarnMsgIdAndTxt functions in the C
Matrix API.
For example, the following code snippet prints prhs[0].
char *buf;
int buflen;
if (mxGetString(prhs[0], buf, buflen) == 0) {
mexPrintf("The input string is: %s\n", buf);
}