[adn258]

So here is the code and I'll explain what it does: I start a whois command line program and it checks a domain in this same class. Depending no whether or not the data received contains "No whois information available." it will set a bool in the class to true or false. If it's true the domain is registered if not it's open. The problem I have is for some reason I don't like the feeling of this but as soon as the program detects no whois information found it uses the KillWhois() function which kills the process!!

For some reason this feels sloppy as I'd rather cancel the event or something but perhaps this is the best I can do for this situation in terms of speed. Note: The code generally DOES work fine for most domains (not always). Ideas, etc? Thanks guys

private bool bIs_Domain_Whois_Available()
        {
            using (var whois = new Process
            {
                StartInfo = new ProcessStartInfo
                {
                    FileName = "whois.exe",
                    Arguments = this.strDomain,
                    UseShellExecute = false,
                    RedirectStandardOutput = true,
                    RedirectStandardError = true,
                    CreateNoWindow = true
                }
            })
            {
                whois.OutputDataReceived += new DataReceivedEventHandler(whois_OutputDataReceived);
                whois.Start();
                whois.BeginOutputReadLine();
                whois.WaitForExit();
                whois.OutputDataReceived -= new DataReceivedEventHandler(whois_OutputDataReceived);
            }
            return (this.bLastWhoisExists);
        }

        private void StopWhois()
        {
            Process[] p = Process.GetProcessesByName("whois.exe");
            foreach (Process whois in p)
            { whois.Kill(); }
        }

        private void whois_OutputDataReceived(object sender, DataReceivedEventArgs e)
        {
            string output = e.Data;
            if (e.Data != null && e.Data != "")
            {
                if (output.Contains("No whois information found"))
                {
                    this.bLastWhoisExists = false;
                    this.StopWhois();
                    return;
                }
                this.bLastWhoisExists = true;
            }   
        }

[Skydiver]

Why run a command line utility when you can talk to a whois server directly via TCP?

http://coderbuddy.wo...is-information/

[adn258]

Skydiver, on 09 January 2013 - 09:39 PM, said:

Why run a command line utility when you can talk to a whois server directly via TCP?

http://coderbuddy.wo...is-information/

I didn't know you could do that...I feel like an idiot...well it's code cleanup time as obviously that's way better lol. For learning purposes though would my above code work for such a thing ok? Pretending it was another program?

[adn258]

Besides my last question I'm using this code now for whois

private List<string> GetWhois()
        {
            List<string> result = new List<string>();
            using (TcpClient tc = new TcpClient(this.strWhoisServer, 43))
            {
                using (NetworkStream netstrea = tc.GetStream())
                {
                    using (BufferedStream buffstream = new BufferedStream(netstrea))
                    {
                        using (StreamWriter sw = new StreamWriter(buffstream))
                        {
                            sw.WriteLine(this.strHostname);
                            sw.Flush();

                            using (StreamReader sr = new StreamReader(buffstream))
                            {
                                while (!sr.EndOfStream)
                                {
                                    result.Add(sr.ReadLine());
                                }
                            }

                        }
                    }
                }
            }
            return result;
        }

It works fine if I don't use using ( with streamwrter but instead dispose of it manually. if THE CODE IS LEFT AS IT IS NOW I get an Object Disposed Exception meaning it was disposed I take it before it could be used but WHY? The last part of the using brace isn't until after Streamreader can someone explain?

[Skydiver]

Give a man a fish:

Both of your StreamWriter and StreamReader are referencing the same buffstream. If you dispose the StreamReader, it will also close and dispose the buffstream. So when the StreamWriter gets around to trying to close and dispose, the buffstream is already disposed.

Teach a man to fish:

Look closely at the callstack from the exception. Then use a reflector tool like Lutz's Reflector or dotNetPeek and look at the code for StreamReader and StreamWriter.

[adn258]

Skydiver, on 10 January 2013 - 05:47 AM, said:

Give a man a fish:

Both of your StreamWriter and StreamReader are referencing the same buffstream. If you dispose the StreamReader, it will also close and dispose the buffstream. So when the StreamWriter gets around to trying to close and dispose, the buffstream is already disposed.

Teach a man to fish:

Look closely at the callstack from the exception. Then use a reflector tool like Lutz's Reflector or dotNetPeek and look at the code for StreamReader and StreamWriter.

But what about just not using using on one of the streamreaders or writers and waiting to call dipose on one of them like so

using (TcpClient tc = new TcpClient(this.strWhoisServer, 43))
            {
                using (NetworkStream netstrea = tc.GetStream())
                {
                    using (BufferedStream buffstream = new BufferedStream(netstrea))
                    {
                        StreamWriter sw = new StreamWriter(buffstream);
                        sw.WriteLine(this.strHostname);
                        sw.Flush();
                        using (StreamReader sr = new StreamReader(buffstream))
                        {
                            while (!sr.EndOfStream)
                            {
                                result = sr.ReadLine();
                                if (result.Contains("Domain Name:"))
                                {return true;}
                            }
                            sw.Dispose();
                        }

                    }

                }
            }

Works just fine. Is there anything wrong with approaching this problem that way? Also it appears (which I didn't get either) that the stream writer IS DISPOSING TOO SOON not the reader this is according to the exception too.

This post has been edited by adn258: 10 January 2013 - 02:22 PM

[Skydiver]

You could potentially use the constructor variant with the leaveOpen flag:
http://msdn.microsof...y/gg712853.aspx
http://msdn.microsof...y/gg712952.aspx

That way you'll feel good about using using for your reader and writer, and the using for the BufferedStream will do the right thing.

This post has been edited by Skydiver: 10 January 2013 - 05:57 PM

[adn258]

Skydiver, on 10 January 2013 - 02:58 PM, said:

You could potentially use the constructor variant with the leaveOpen flag:
http://msdn.microsof...y/gg712853.aspx
http://msdn.microsof...y/gg712952.aspx

That way you'll feel good about using using for your reader and writer, and the using for the BufferedStream will do the right thing.

I tried this. For some Odd crazy reason I Would fill in those arguments to the streamwriter class perfectly and allocate 512 bytes which should be more than enough and I kept getting errors like about invalid arguments. Weirder yet is the last option doesn't show in the code suggestions as I'm typing you know where it shows you the next argument etc. it doesn't say leaveopen...very weird. I appreciate that though. I wonder what's happening?

[Skydiver]

I think that variant is only available if you are targeting .NET 4.5.

[adn258]

Skydiver, on 12 January 2013 - 11:08 AM, said:

I think that variant is only available if you are targeting .NET 4.5.

Yes you are correct...and I do want to target that...so is it acceptable in terms of just calling dispose like I did in the code above? It isn't quite as pretty but it does insure it will be disposed of in the end correct and it's a work around?