quick dtrace

#!/usr/sbin/dtrace -Cs

struct  hostent {
        char    *h_name;        /* official name of host */
        char    **h_aliases;    /* alias list */
        int     h_addrtype;     /* host address type */
        int     h_length;       /* length of address */
        char    **h_addr_list;  /* list of addresses from name server */
};

typedef struct hostent hostent_t;

pid$target::getipnodebyname:entry {
        self->name = arg0;
        self->errno = arg3;
}
pid$target::getipnodebyname:return / self->name / {
        ustack(10);
}

pid$target::getipnodebyname:return / self->name / {
        printf("looked up host %s errno is %d\n", copyinstr(self->name), *(int *)copyin(self->errno,sizeof(int)));
        self->hostent = (hostent_t *)copyin(arg1,sizeof(hostent_t));
        printf("hostent->h_name is %s\n", copyinstr((uintptr_t)self->hostent->h_name));
        printf("hostent->h_length is %d", self->hostent->h_length);
        self->name = 0;
}