GetProcessSample02 Sample

This sample shows how to write a cmdlet that retrieves the processes on the local computer. It provides a Name parameter that can be used to specify the processes to be retrieved. This cmdlet is a simplified version of the Get-Process cmdlet provided by Windows PowerShell.

How to build the sample using Visual Studio.

  1. Open Windows Explorer and navigate to the GetProcessSample02 directory under the Samples directory.

  2. Double-click the icon for the solution (.sln) file. This opens the sample project in Visual Studio.

  3. In the Build menu, select Build Solution.

The library for the sample will be built in the default \bin or \bin\debug directories.

How to run the sample

  1. Create the following module folder:

    [user]/documents/windowspowershell/modules/GetProcessSample02

  2. Copy the sample assembly to the module folder.

  3. Start Windows PowerShell.

  4. Run the following command to load the assembly into Windows PowerShell:

    import-module getprossessample02

  5. Run the following command to run the cmdlet:

    get-proc

Requirements

This sample requires Windows PowerShell 2.0.

Demonstrates

This sample demonstrates the following.

  • Declaring a cmdlet class using the Cmdlet attribute.

  • Declaring a cmdlet parameter using the Parameter attribute.

  • Specifying the position of the parameter.

  • Declaring a validation attribute for the parameter input.

Example

The following code shows an implementation of the Get-Proc cmdlet that includes a Name parameter.

namespace Microsoft.Samples.PowerShell.Commands
{
  using System;
  using System.Diagnostics;
  using System.Management.Automation;     // Windows PowerShell namespace
  
  #region GetProcCommand
  
  /// <summary>
  /// This class implements the get-proc cmdlet.
  /// </summary>
  [Cmdlet(VerbsCommon.Get, "Proc")]
  public class GetProcCommand : Cmdlet
  {
    #region Parameters

    /// <summary>
    /// The names of the processes retrieved by the cmdlet.
    /// </summary>
    private string[] processNames;
      
    /// <summary>
    /// Gets or sets the list of process names on which 
    /// the Get-Proc cmdlet will work.
    /// </summary>
    [Parameter(Position = 0)]
    [ValidateNotNullOrEmpty]
    public string[] Name
    {
      get { return this.processNames; }
      set { this.processNames = value; }
    }
        
    #endregion Parameters
    
    #region Cmdlet Overrides
    
    /// <summary>
    /// The ProcessRecord method calls the Process.GetProcesses 
    /// method to retrieve the processes specified by the Name 
    /// parameter. Then, the WriteObject method writes the 
    /// associated process objects to the pipeline.
    /// </summary>
    protected override void ProcessRecord()
    {
      // If no process names are passed to the cmdlet, get all 
      // processes.
      if (this.processNames == null)
      {
        WriteObject(Process.GetProcesses(), true);
      }
      else
      {
        // If process names are passed to cmdlet, get and write 
        // the associated processes.
        foreach (string name in this.processNames)
        {
          WriteObject(Process.GetProcessesByName(name), true);
        }
      } // End if (processNames...).
    } // End ProcessRecord.
    #endregion Cmdlet Overrides
  } // End GetProcCommand class.
  #endregion GetProcCommand
}

See Also



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