func NewResolvConf(path string) (*ResolvConf, error) {
	rc := &ResolvConf{
		OptMisc: make(map[string]bool),
	}
	reader, err := libio.NewReader(path)
	if err != nil {
		return nil, err
	}
	rc.parse(reader)
	return rc, nil
}
NewResolvConf open resolv.conf file in path and return the parsed records.
package net
import (
	"os"
	"strconv"
	"strings"
	"github.com/shuLhan/share/lib/ascii"
	libio "github.com/shuLhan/share/lib/io"
)
const (
	envLocaldomain = "LOCALDOMAIN"
)
var (
	newLineTerms = []byte{'\n'}
	getHostname = os.Hostname
)
type ResolvConf struct {
	Domain string
	Search []string
	NameServers []string
	NDots int
	Timeout int
	Attempts int
	OptMisc map[string]bool
}