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);
}