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Resolv.conf 修改破坏了 DNS

tag-icon • tag-icon debian dns mono c# resolv.conf
Resolv.conf 修改破坏了 DNS

这是一个奇怪的问题，但我似乎无法解决它。

我正在创建一个可视化用户界面来修改 Debian Wheezy（以及偶然兼容的其他 debian 版本/衍生物）上的互联网设置。

我希望能够根据用户插入的内容修改 DNS。

   用户界面

按下“保存”后，运行以下代码：

void SaveDNSButton_event(object obj, ButtonPressEventArgs args)
    {
        //save dns settings
        string s1 = "";
        string s2 = "";

        string toWrite = s1 + s2;
        Console.WriteLine ("=============");
        Console.WriteLine ("Reading from resolv.conf before writing...");
        using (StreamReader confReader = File.OpenText ("/etc/resolv.conf")) {
            StringReader sr = new StringReader (confReader.ReadToEnd ());
            string line;
            toWrite = "";
            while (null != (line = sr.ReadLine ())) {
                if (line.Contains ("nameserver")) {
                    Console.WriteLine (line);
                } else {
                    toWrite += line + Environment.NewLine;
                }
            }
            confReader.Dispose ();
            confReader.Close ();
        }

        s1 = "nameserver " + DNSentry1.Text + ";" + Environment.NewLine;
        s2 = "nameserver " + DNSentry2.Text + ";" +  Environment.NewLine;


        Console.WriteLine ("=============");
        Console.WriteLine ("Writing to resolv.conf");
        Console.WriteLine ("To write: " + toWrite + s1 + s2);

        using (StreamWriter confWriter = new StreamWriter ("/etc/resolv.conf", false)) {
            Console.WriteLine ("Writing...");
            confWriter.Write (toWrite + s1 + s2);
            Console.WriteLine ("Closing file stream...");
            confWriter.Dispose ();
            confWriter.Close ();
        }


        Console.WriteLine ("=============");

        Console.WriteLine ("Opening conf to confirm if it worked");
        if (IsLinux) {
            Console.WriteLine ("Trying to open conf");
            StreamReader file = File.OpenText ("/etc/resolv.conf");
            string s = file.ReadToEnd ();
            Console.WriteLine(s);

            file.Dispose ();
            file.Close ();
        }
    }

相关部分是

using (StreamWriter confWriter = new StreamWriter ("/etc/resolv.conf", false)) {
            Console.WriteLine ("Writing...");
            confWriter.Write (toWrite + s1 + s2);
            Console.WriteLine ("Closing file stream...");
            confWriter.Dispose ();
            confWriter.Close ();
        }

其中我resolv.conf用填写的 DNS 信息覆盖。输入的示例类似于第一个对话框中的“8.8.8.8”和第二个对话框中的“8.8.4.4”。输出将是...

=============
Reading from resolv.conf before writing...
nameserver 192.168.2.101
nameserver 8.8.8.8
=============
Writing to resolv.conf
To write: # Generated by NetworkManager
domain trin-it.local
search trin-it.local
nameserver 8.8.8.8;
nameserver 8.8.4.4;

Writing...
Closing file stream...
=============
Opening conf to confirm if it worked
4
Trying to open conf
# Generated by NetworkManager
domain trin-it.local
search trin-it.local
nameserver 8.8.8.8;
nameserver 8.8.4.4;

如果我在此之后 ping google，它只会说：“未知主机 google”

但是，如果我手动转到resolv.conf并更改那里的名称服务器，它实际上可以很好地解析。这是怎么回事？/etc/resolv.conf据我所知，唯一的变化是我通过代码而不是仅仅 nano 来完成此操作。有人能解释一下吗？

长话短说

为什么使用代码编辑 resolv.conf 与手动编辑它相比不起作用？难道不是同一件事吗？

答案1

在我看来，您的代码在名称服务器行的末尾添加了一个分号；不要那样做。

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