tsoome@beastie:~$ more sysevent.d
#!/usr/sbin/dtrace -s

#pragma D option quiet

BEGIN
{
        printf("%-30s  %-20s  %s\n", "PUBLISHER", "CLASS",
            "SUBCLASS");
}

sysevent:::post
/args[0]->ec_name == NULL/
{
        printf("%-30s  %-20s  %s\n", args[1]->se_publisher,
            args[1]->se_class, args[1]->se_subclass);
}