return "", nil, handlePlan9DNSError(err, name)
	}
	for _, line := range lines {
		f := getFields(line)
		if len(f) < 6 {
			continue
		}
		port, _, portOk := dtoi(f[4])
		priority, _, priorityOk := dtoi(f[3])
		weight, _, weightOk := dtoi(f[2])
		if !(portOk && priorityOk && weightOk) {
			continue
		}
		addrs = append(addrs, &SRV{absDomainName(f[5]), uint16(port), uint16(priority), uint16(weight)})

	}

	fields := getFields(line)
	if len(fields) < 4 {
		return nil, errors.New("invalid interface status file: " + ifcstat)
	}

	device := fields[1]
	mtustr := fields[3]

	mtu, _, ok := dtoi(mtustr)
	if !ok {
		return nil, errors.New("invalid status file of interface: " + ifcstat)
	}
	ifc.MTU = mtu

	// Not a loopback device ("/dev/null") or packet interface (e.g. "pkt2")

					n, _, _ := dtoi(s[6:])
					if n < 0 {
						n = 0
					} else if n > 15 {
						n = 15
					}
					conf.ndots = n
				case stringslite.HasPrefix(s, "timeout:"):
					n, _, _ := dtoi(s[8:])
					if n < 1 {
						n = 1
					}
					conf.timeout = time.Duration(n) * time.Second
				case stringslite.HasPrefix(s, "attempts:"):
					n, _, _ := dtoi(s[9:])
					if n < 1 {
						n = 1
					}

	if err != nil {
		return syscall.SOMAXCONN
	}
	defer fd.close()
	l, ok := fd.readLine()
	if !ok {
		return syscall.SOMAXCONN
	}
	f := getFields(l)
	n, _, ok := dtoi(f[0])
	if n == 0 || !ok {
		return syscall.SOMAXCONN
	}

	if n > 1<<16-1 {
		return maxAckBacklog(n)
	}
	return n

		if i := bytealg.IndexByteString(line, '#'); i >= 0 {
			line = line[:i]
		}
		f := getFields(line)
		if len(f) < 2 {
			continue
		}
		portnet := f[1] // "80/tcp"
		port, j, ok := dtoi(portnet)
		if !ok || port <= 0 || j >= len(portnet) || portnet[j] != '/' {
			continue
		}
		netw := portnet[j+1:] // "tcp"
		m, ok1 := services[netw]
		if !ok1 {
			m = make(map[string]int)
			services[netw] = m

		off int
		ok  bool
	}{
		{"", 0, 0, false},
		{"0", 0, 1, true},
		{"65536", 65536, 5, true},
		{"123456789", big, 8, false},
		{"-0", 0, 0, false},
		{"-1234", 0, 0, false},
	} {
		n, i, ok := dtoi(tt.in)
		if n != tt.out || i != tt.off || ok != tt.ok {
			t.Errorf("got %d, %d, %v; want %d, %d, %v", n, i, ok, tt.out, tt.off, tt.ok)
		}
	}

		// tcp    6   TCP    # transmission control protocol
		if i := bytealg.IndexByteString(line, '#'); i >= 0 {
			line = line[0:i]
		}
		f := getFields(line)
		if len(f) < 2 {
			continue
		}
		if proto, _, ok := dtoi(f[1]); ok {
			if _, ok := protocols[f[0]]; !ok {
				protocols[f[0]] = proto
			}
			for _, alias := range f[2:] {
				if _, ok := protocols[alias]; !ok {
					protocols[alias] = proto
				}
			}
		}
	}

	rx := regexp.MustCompile(`(?m)^([a-z0-9.\-]+)\s+mail exchanger\s*=\s*([0-9]+)\s*([a-z0-9.\-]+)$`)
	for _, ans := range rx.FindAllStringSubmatch(r, -1) {
		pref, _, _ := dtoi(ans[2])
		mx = append(mx, &MX{absDomainName(ans[3]), uint16(pref)})
	}
	// windows nslookup syntax
	// gmail.com       MX preference = 30, mail exchanger = alt3.gmail-smtp-in.l.google.com

// Bigger than we need, not too big to worry about overflow
const big = 0xFFFFFF

// Decimal to integer.
// Returns number, characters consumed, success.
func dtoi(s string) (n int, i int, ok bool) {
	n = 0
	for i = 0; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
		n = n*10 + int(s[i]-'0')
		if n >= big {
			return big, i, false
		}
	}
	if i == 0 {

	i := bytealg.IndexByteString(s, '!')
	if i >= 0 {
		addr = ParseIP(s[:i])
		if addr == nil {
			return nil, 0, &ParseError{Type: "IP address", Text: s}
		}
	}
	p, plen, ok := dtoi(s[i+1:])
	if !ok {
		return nil, 0, &ParseError{Type: "port", Text: s}
	}
	if p < 0 || p > 0xFFFF {
		return nil, 0, &AddrError{Err: "invalid port", Addr: s[i+1 : i+1+plen]}
	}
	return addr, p, nil
}