Debug Messages

Debug messages can help us understand the rest of the code
Console debug messages:
#ifdef DEBUG
    if (trace == NULL)
        trace = fopen("bgtrace", "w");
    fprintf(trace, "\nRoll:  %d %d%s\n", D0, D1, race ? " (race)" : "");
    fflush(trace);
#endif
System log messages:
syslog(LOG_DEBUG, "Successful lookup: %d , %d : %s\n",
lport, fport, pwp->pw_name);
Different debug levels:
if (debug > 4)
printf("systime: offset %s\n", lfptoa(now, 6));