MLGetMessageHandler()

#include "mathlink.h"

/* a function to read MathLink urgent messages */

void AppMessageHandler(MLINK link, int m1, int m2)
{
    /* ... */
}


/* check that a link uses AppMessageHandler for urgent messages */

void check_the_message_handler(MLINK link)
{
    MLMessageHandlerObject handler;

    handler = MLGetMessageHandler(link);
    if(handler != (MLMessageHandlerObject)AppMessageHandler)
    {
        if(! MLSetMessageHandler(link, (MLMessageHandlerObject)AppMessageHandler))
            { /* unable to set AppMessageHandler as the handler for
                 link */ }
    }
}