\begin{verbatim}

#include <stdio.h>
#include <stdlib.h>
#include <gnutls/gnutls.h>

/* This function will check whether the given return code from
 * a gnutls function (recv/send), is an alert, and will print
 * that alert.
 */
void check_alert(gnutls_session_t session, int ret)
{
   int last_alert;

   if (ret == GNUTLS_E_WARNING_ALERT_RECEIVED
       || ret == GNUTLS_E_FATAL_ALERT_RECEIVED) {
      last_alert = gnutls_alert_get(session);

      /* The check for renegotiation is only useful if we are 
       * a server, and we had requested a rehandshake.
       */
      if (last_alert == GNUTLS_A_NO_RENEGOTIATION &&
          ret == GNUTLS_E_WARNING_ALERT_RECEIVED)
         printf("* Received NO_RENEGOTIATION alert. "
                "Client Does not support renegotiation.\n");
      else
         printf("* Received alert '%d': %s.\n", last_alert,
                gnutls_alert_get_name(last_alert));
   }
}

\end{verbatim}
