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How to Execute a Command in C# ?

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12 May 2008CPOL2 min read 720.8K   12.4K   94   32
This article will help you to execute a command in C#, just like we execute a command using the Windows command prompt

Introduction

It is normal practice to open the Windows command prompt and execute commands. The command when executed shows the result onto the screen. There are many commands that we execute daily such as dir, find, etc. A situation may arise when you want to execute a (shell) command from the C# application.

Don't worry!!! Here is the code to do so…

Using the Code

The code given below creates a process i.e. a command process and then invokes the command that we want to execute. The result of the command is stored in a string variable, which can then be used for further reference. The command execution can happen in two ways, synchronously and asynchronously. In the asynchronous command execution, we just invoke the command execution using a thread that runs independently. The code has enough comments, hence making it self-explanatory.

Below is the code to execute the command synchronously:

C#
/// <summary>
/// Executes a shell command synchronously.
/// </summary>
/// <param name="command">string command</param>
/// <returns>string, as output of the command.</returns>
public void ExecuteCommandSync(object command)
{
     try
     {
         // create the ProcessStartInfo using "cmd" as the program to be run,
         // and "/c " as the parameters.
         // Incidentally, /c tells cmd that we want it to execute the command that follows,
         // and then exit.
    System.Diagnostics.ProcessStartInfo procStartInfo =
        new System.Diagnostics.ProcessStartInfo("cmd", "/c " + command);

    // The following commands are needed to redirect the standard output.
    // This means that it will be redirected to the Process.StandardOutput StreamReader.
    procStartInfo.RedirectStandardOutput = true;
    procStartInfo.UseShellExecute = false;
    // Do not create the black window.
    procStartInfo.CreateNoWindow = true;
    // Now we create a process, assign its ProcessStartInfo and start it
    System.Diagnostics.Process proc = new System.Diagnostics.Process();
    proc.StartInfo = procStartInfo;
    proc.Start();
    // Get the output into a string
    string result = proc.StandardOutput.ReadToEnd();
    // Display the command output.
    Console.WriteLine(result);
      }
      catch (Exception objException)
      {
      // Log the exception
      }
}

The above code invokes the cmd process specifying the command to be executed. The option procStartInfo.RedirectStandardOutput is set to true, since we want the output to be redirected to the StreamReader. The procStartInfo.CreateNoWindow property is set to true, as we don't want the standard black window to appear. This will execute the command silently.

Below is the code to execute the command asynchronously:

C#
/// <summary>
/// Execute the command Asynchronously.
/// </summary>
/// <param name="command">string command.</param>
public void ExecuteCommandAsync(string command)
{
   try
   {
    //Asynchronously start the Thread to process the Execute command request.
    Thread objThread = new Thread(new ParameterizedThreadStart(ExecuteCommandSync));
    //Make the thread as background thread.
    objThread.IsBackground = true;
    //Set the Priority of the thread.
    objThread.Priority = ThreadPriority.AboveNormal;
    //Start the thread.
    objThread.Start(command);
   }
   catch (ThreadStartException objException)
   {
    // Log the exception
   }
   catch (ThreadAbortException objException)
   {
    // Log the exception
   }
   catch (Exception objException)
   {
    // Log the exception
   }
}

If we observe carefully, the asynchronous execution of the command actually invokes the synchronous command execution method using a thread. The thread runs in the background making the command execution asynchronous in nature.

In the above execution sample, we find that there are two result sets of the command "dir". The first one appears immediately after the command and the second appears after the "Done!" statement. In this case, the first one is the synchronous execution of the command, which happens immediately and the second is the asynchronous execution of the "dir" command.

Points of Interest

I always thought of having some code that will execute my DOS commands, finally I had to build it.

You can find some more interesting stuff here.

History

  • 12th May, 2008: Initial post

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer (Senior)
United States United States
Sandeep has 9+ yrs of IT experience. He is Microsoft Certified Technology Specialist and has been certified for Analyzing Requirements and Defining Microsoft .NET Solution Architectures.
He is an active member of:
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2. CodeProject.com
3. Community-Credit.com
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Comments and Discussions

 
QuestionWhat is wrong with my command? How to solve it? Pin
Ole Kullmann29-Jun-21 21:38
Ole Kullmann29-Jun-21 21:38 
AnswerRe: What is wrong with my command? How to solve it? Pin
Ole Kullmann29-Jun-21 23:29
Ole Kullmann29-Jun-21 23:29 
QuestionThis article is being copied without permission Pin
Raj00630-Jul-19 20:04
Raj00630-Jul-19 20:04 
Questionhow to execute dotnet test command in this program? Pin
Member 1389141828-Jun-18 11:56
Member 1389141828-Jun-18 11:56 
QuestionPDF not generated Pin
Keepr13-Dec-16 1:14
Keepr13-Dec-16 1:14 
GeneralMy vote of 5 Pin
hasiabewardana3-Apr-16 22:06
hasiabewardana3-Apr-16 22:06 
BugWorks, but not with commands that need additional input Pin
Member 1206637117-Oct-15 8:19
Member 1206637117-Oct-15 8:19 
GeneralMy vote of 5 Pin
Member 1178934324-Jun-15 4:56
Member 1178934324-Jun-15 4:56 
Questionproject not opening Pin
Divsheen29-Apr-15 1:32
Divsheen29-Apr-15 1:32 
Questionhow to execute command lines from C# Pin
Member 1139937124-Jan-15 5:21
Member 1139937124-Jan-15 5:21 
AnswerRe: how to execute command lines from C# Pin
PIEBALDconsult24-Jan-15 5:25
mvePIEBALDconsult24-Jan-15 5:25 
GeneralRe: how to execute command lines from C# Pin
Member 1139937124-Jan-15 8:01
Member 1139937124-Jan-15 8:01 
QuestionCannot read configuration file due to insufficient permissions. Pin
hernaldo.gonzalez28-May-14 11:52
hernaldo.gonzalez28-May-14 11:52 
AnswerRe: Cannot read configuration file due to insufficient permissions. Pin
Sandeep Aparajit29-Aug-14 13:23
Sandeep Aparajit29-Aug-14 13:23 
GeneralRe: Cannot read configuration file due to insufficient permissions. Pin
Member 110683632-Dec-14 21:49
Member 110683632-Dec-14 21:49 
QuestionI have problem needs your help Pin
osamaworx23-Jan-14 4:21
osamaworx23-Jan-14 4:21 
GeneralMy vote of 5 Pin
Gun Gun Febrianza29-May-13 7:55
Gun Gun Febrianza29-May-13 7:55 
QuestionNot working :-( Pin
Amogh Natu22-May-13 0:19
professionalAmogh Natu22-May-13 0:19 
GeneralMy vote of 5 Pin
Member 83129214-Oct-12 3:06
Member 83129214-Oct-12 3:06 
Question:) Pin
naymyohaen2-Jul-12 22:45
naymyohaen2-Jul-12 22:45 
GeneralMy vote of 5 Pin
Carlos ABS11-Apr-12 3:54
Carlos ABS11-Apr-12 3:54 
GeneralMy vote of 5 Pin
Milton Rodríguez22-Nov-11 3:46
Milton Rodríguez22-Nov-11 3:46 
QuestionWhat if i want a continues commands?? Pin
RIKISH2-Nov-11 0:34
RIKISH2-Nov-11 0:34 
Questionre:How to Execute a Command in C# ? Pin
hafizhanif31-Oct-11 21:26
hafizhanif31-Oct-11 21:26 
GeneralMy vote of 5 Pin
IanJ196525-May-11 21:39
IanJ196525-May-11 21:39 

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