Handling Errors and Writing a Print Handler (Using the C Math Library)

Using the C Math Library

Providing Your Own Print Handler

Instead of calling printf directly, the MATLAB C Math Library calls a print handler when it needs to display an error message or warning. The default print handler used by the library takes a single argument, a const char * (the message to be displayed), and returns void.

The default print handler is

static void DefaultPrintHandler(const char *s)
{
    printf("%s",s);
}

The routine sends its output to C's stdout, using the printf function.

If you want to perform a different style of output, you can write your own print handler and register it with the MATLAB C Math Library. Any print handler that you write must match the prototype of the default print handler: a single const char * argument and a void return.

To register your function and change which print handler the library uses, you must call the routine mlfSetPrintHandler.

mlfSetPrintHandler takes a single argument, a pointer to a function that displays the character string, and returns void.

void mlfSetPrintHandler ( void ( * PH)(const char *) );

Defining a Print Handler Sending Output to a GUI