How to use command prompt using c# and getting the results line by line?

Question

I have a program where i have a .exe file. The work of the .exe is to scan the directories for corrupted files. If accessed through the command prompt in the following format i get the result of scan

"location of exe" "files or folders to be scanned"

the result i get is as the scan goes on. Like

D:\A scanned
D:\B scanned
D:\C scanned
D:\D scanned

Now my question is how can i get the result line by line using c#.

I'm using the following set of codes by i get only the end result. I need the output line by line

The code is as follows:

        string tempGETCMD = null;
        Process CMDprocess = new Process();
        System.Diagnostics.ProcessStartInfo StartInfo = new System.Diagnostics.ProcessStartInfo();
        StartInfo.FileName = "cmd"; //starts cmd window
        StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
        StartInfo.CreateNoWindow = true;
        StartInfo.RedirectStandardInput = true;
        StartInfo.RedirectStandardOutput = true;
        StartInfo.UseShellExecute = false; //required to redirect
        CMDprocess.StartInfo = StartInfo;
        CMDprocess.Start();
        System.IO.StreamReader SR = CMDprocess.StandardOutput;
        System.IO.StreamWriter SW = CMDprocess.StandardInput;
        SW.WriteLine("@echo on");
        SW.WriteLine(@"E:\Scanner\Scanner.exe -r E:\Files to be scanned\"); //the command you wish to run.....


        SW.WriteLine("exit"); //exits command prompt window
        tempGETCMD = SR.ReadToEnd(); //returns results of the command window
        SW.Close();
        SR.Close();
        return tempGETCMD;

Any help in this would be apprecitated

Thanks,

King King · Accepted Answer · 2013-08-24 14:50:59Z

1

I think you have to use a dedicated thread to read every new line from the StandardOutput stream, something like this:

    //This will append each new line to your textBox1 (multiline)
    private void AppendLine(string line)
    {
        if (textBox1.InvokeRequired){
            if(textBox1.IsHandleCreated) textBox1.Invoke(new Action<string>(AppendLine), line);
        }
        else if(!textBox1.IsDisposed) textBox1.AppendText(line + "\r\n");
    }
    //place this code in your form constructor
    Shown += (s, e) => {
      new Thread((() =>
      {          
        while (true){
           string line = CMDProcess.StandardOutput.ReadLine();
           AppendLine(line);    
           //System.Threading.Thread.Sleep(100); <--- try this to see it in action   
       }
     })).Start();
   };
   //Now every time your CMD outputs something, the lines will be printed (in your textBox1) like as you see in the CMD console window.

answered Aug 24, 2013 at 14:50

King King

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3 Comments

Vikneshwar Over a year ago

Hi King King, i tried doing it. But can you tell what is "Shown" Do i have to apply the code after SW.WriteLine(@"E:\Scanner\Scanner.exe -r E:\Files to be scanned\"); Im not sure how to go about doing this? Can u please help.

King King Over a year ago

@Vikneshwar Shown+=(s,e) is to register the Shown event handler, you can place it in your form constructor. After shown, you can call SW.WriteLine(@"E:\Scanner\Scanner.exe -r E:\Files to be scanned\"); whenever you want, such as in a Click event handler of a Button.

Vikneshwar Over a year ago

Yeah sorry King King i forgot to respond back. Eventually i did it and have accomplished my task. Thanks

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