nextitem
while ((next = nextitem(thisitem, nbackp)) != NULL && (next <= nbackp)) {
next = nextitem(next, nfrontp);
thisitem = nextitem(thisitem, nfrontp);
char *nextitem(char *, const char *);
while ((next = nextitem(thisitem)) <= netobuf.send) {
next = nextitem(next);
thisitem = nextitem(thisitem);