Double pointer's usages (on going)

The first usage of the double pointer is to allocate memory for a given pointer:

         nlp = &res.readdir_res_u.list;

while (d = readdir(dirp)) {

nl = *nlp = (namenode *)malloc(sizeof(namenode));

nl->name = strdup(d->d_name);

nlp = &nl->pNext;

}

*nlp = NULL;

This comes from "Power Programming with RPC P84"