Ejemplo GetProcessSample05

En este ejemplo se muestra una versión completa del cmdlet Get-Proc.

Cómo compilar el ejemplo mediante Visual Studio.

1. Abra el Explorador de Windows y vaya al directorio GetProcessSample05 en el directorio Ejemplos.

   Con el SDK de Windows PowerShell 2.0 instalado, vaya a la carpeta GetProcessSample05. La ubicación predeterminada es C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0\Samples\sysmgmt\WindowsPowerShell\csharp\GetProcessSample05.

2. Haga doble clic en el icono del archivo de solución (.sln). Se abre el proyecto de ejemplo en Visual Studio.

3. En el menú compilación de, seleccione Compilar solución para compilar la biblioteca para el ejemplo en las carpetas de \bin o \bin\debug predeterminadas.

Cómo ejecutar el ejemplo

1. Cree la siguiente carpeta de módulo:

   [user]\Documents\WindowsPowerShell\Modules\GetProcessSample05

2. Copie el ensamblado de ejemplo en la carpeta del módulo.

3. Inicie Windows PowerShell.

4. Ejecute el siguiente comando para cargar el ensamblado en Windows PowerShell:

   Import-Module getprossessample05

5. Ejecute el siguiente comando para ejecutar el cmdlet :

   Get-Proc

Requisitos

Este ejemplo requiere Windows PowerShell 2.0.

Demostraciones

En este ejemplo se muestra lo siguiente.

• Declarar una clase de cmdlet mediante el atributo Cmdlet.

• Declarar un parámetro de cmdlet mediante el atributo Parameter.

• Especificar posiciones para parámetros.

• Especificar que los parámetros pueden tomar la entrada de la canalización. La entrada se puede tomar de un objeto o un valor de una propiedad de un objeto cuyo nombre de propiedad es el mismo que el nombre del parámetro.

• Declarar un atributo de validación para la entrada del parámetro.

• Control de errores y excepciones.

• Escribir mensajes de depuración.

Ejemplo

En este ejemplo se muestra cómo crear un cmdlet que muestra una lista de procesos especificados.

namespace Microsoft.Samples.PowerShell.Commands
{
    using System;
    using System.Collections.Generic;
    using System.Diagnostics;
    using System.Management.Automation;    // Windows PowerShell namespace.
    using System.Security.Permissions;
    using Win32Exception = System.ComponentModel.Win32Exception;
    #region GetProcCommand

    /// <summary>
   /// This class implements the Get-Proc cmdlet.
   /// </summary>
   [Cmdlet(VerbsCommon.Get, "Proc",
      DefaultParameterSetName = "ProcessName")]
   public class GetProcCommand : PSCmdlet
   {
       #region Fields
       /// <summary>
       /// The names of the processes to act on.
       /// </summary>
       private string[] processNames;

       /// <summary>
       /// The identifiers of the processes to act on.
       /// </summary>
       private int[] processIds;

       /// <summary>
       /// The process objects to act on.
       /// </summary>
       private Process[] inputObjects;

       #endregion Fields

       #region Parameters

      /// <summary>
      /// Gets or sets the list of process names on
      /// which the Get-Proc cmdlet will work.
      /// </summary>
      [Parameter(
         Position = 0,
         ParameterSetName = "ProcessName",
         ValueFromPipeline = true,
         ValueFromPipelineByPropertyName = true)]
      [ValidateNotNullOrEmpty]
      public string[] Name
      {
         get { return this.processNames; }
         set { this.processNames = value; }
      }

      /// <summary>
      /// Gets or sets the list of process identifiers on
      /// which the Get-Proc cmdlet will work.
      /// </summary>
      [Parameter(
         ParameterSetName = "Id",
         Mandatory = true,
         ValueFromPipeline = true,
         ValueFromPipelineByPropertyName = true,
         HelpMessage = "The unique id of the process to get.")]
      public int[] Id
      {
         get { return this.processIds; }
         set { this.processIds = value; }
      }

      /// <summary>
      /// Gets or sets Process objects directly. If the input is a
      /// stream of [collection of] Process objects, the cmdlet bypasses the
      /// ProcessName and Id parameters and reads the Process objects
      /// directly.  This allows the cmdlet to deal with processes that have
      /// wildcard characters in their name.
      /// <value>Process objects</value>
      /// </summary>
      [Parameter(
         ParameterSetName = "InputObject",
         Mandatory = true,
         ValueFromPipeline = true)]
      public Process[] Input
      {
         get { return this.inputObjects; }
         set { this.inputObjects = value; }
      }

      #endregion Parameters

      #region Cmdlet Overrides

      /// <summary>
      /// The ProcessRecord method calls the Process.GetProcesses
      /// method to retrieve the processes. Then, the WriteObject
      /// method writes the associated processes to the pipeline.
      /// </summary>
      protected override void ProcessRecord()
      {
         List<Process> matchingProcesses;

         WriteDebug("Obtaining the list of matching process objects.");

         switch (ParameterSetName)
         {
            case "Id":
               matchingProcesses = this.GetMatchingProcessesById();
               break;
            case "ProcessName":
               matchingProcesses = this.GetMatchingProcessesByName();
               break;
            case "InputObject":
               matchingProcesses = this.GetProcessesByInput();
               break;
            default:
               ThrowTerminatingError(
                   new ErrorRecord(
                       new ArgumentException("Bad ParameterSetName"),
                       "UnableToAccessProcessList",
                       ErrorCategory.InvalidOperation,
                       null));
               return;
         } // switch (ParameterSetName)

         WriteDebug("Outputting the matching process objects.");

         matchingProcesses.Sort(ProcessComparison);

         foreach (Process process in matchingProcesses)
         {
            WriteObject(process);
         }
      } // ProcessRecord

      #endregion Overrides

      #region protected Methods and Data

      /// <summary>
      /// Retrieves the list of all processes matching the ProcessName
      /// parameter and generates a non-terminating error for each
      /// specified process name which is not found even though the name
      /// contains no wildcards.
      /// </summary>
      /// <returns>The matching processes.</returns>
      [EnvironmentPermissionAttribute(
         SecurityAction.LinkDemand,
         Unrestricted = true)]
      private List<Process> GetMatchingProcessesByName()
      {
         new EnvironmentPermission(
            PermissionState.Unrestricted).Assert();

         List<Process> allProcesses =
            new List<Process>(Process.GetProcesses());

         // The keys dictionary is used for rapid lookup of
         // processes that are already in the matchingProcesses list.
         Dictionary<int, byte> keys = new Dictionary<int, byte>();

         List<Process> matchingProcesses = new List<Process>();

         if (null == this.processNames)
         {
             matchingProcesses.AddRange(allProcesses);
         }
         else
         {
             foreach (string pattern in this.processNames)
             {
                 WriteVerbose("Finding matches for process name \""
                    + pattern + "\".");

                 // WildCard search on the available processes
                 WildcardPattern wildcard =
                    new WildcardPattern(
                        pattern,
                        WildcardOptions.IgnoreCase);

                 bool found = false;

                 foreach (Process process in allProcesses)
                 {
                     if (!keys.ContainsKey(process.Id))
                     {
                         string processName = SafeGetProcessName(process);

                         // Remove the process from the allProcesses list
                         // so that it is not tested again.
                         if (processName.Length == 0)
                         {
                             allProcesses.Remove(process);
                         }

                         // Perform a wildcard search on this particular
                         // process name and check whether it matches the
                         // pattern specified.
                         if (!wildcard.IsMatch(processName))
                         {
                             continue;
                         }

                         WriteDebug("Found matching process id "
                            + process.Id + ".");

                         // A match is found.
                         found = true;

                         // Store the process identifier so that the same process
                         // is not added twice.
                         keys.Add(process.Id, 0);

                         // Add the process to the processes list.
                         matchingProcesses.Add(process);
                     }
                 } // foreach (Process...

                 if (!found &&
                   !WildcardPattern.ContainsWildcardCharacters(pattern))
                 {
                     WriteError(new ErrorRecord(
                        new ArgumentException("Cannot find process name "
                           + "\"" + pattern + "\"."),
                        "ProcessNameNotFound",
                        ErrorCategory.ObjectNotFound,
                        pattern));
                 }
             } // foreach (string...
         } // if (null...

         return matchingProcesses;
      } // GetMatchingProcessesByName

      /// <summary>
      /// Returns the name of a process.  If an error occurs, a blank
      /// string is returned.
      /// </summary>
      /// <param name="process">The process whose name is
      /// returned.</param>
      /// <returns>The name of the process.</returns>
      [EnvironmentPermissionAttribute(
         SecurityAction.LinkDemand, Unrestricted = true)]
      protected static string SafeGetProcessName(Process process)
      {
         new EnvironmentPermission(PermissionState.Unrestricted).Assert();
         string name = String.Empty;

         if (process != null)
         {
            try
            {
                return process.ProcessName;
            }
            catch (Win32Exception)
            {
            }
            catch (InvalidOperationException)
            {
            }
         }

         return name;
     } // SafeGetProcessName

      #endregion Cmdlet Overrides

      #region Private Methods

      /// <summary>
      /// Function to sort by process name first, and then by
      /// the process identifier.
      /// </summary>
      /// <param name="x">First process object.</param>
      /// <param name="y">Second process object.</param>
      /// <returns>
      /// Returns less than zero if x is less than y,
      /// greater than 0 if x is greater than y, and 0 if x == y.
      /// </returns>
      private static int ProcessComparison(Process x, Process y)
      {
         int diff = String.Compare(
            SafeGetProcessName(x),
            SafeGetProcessName(y),
            StringComparison.CurrentCultureIgnoreCase);

         if (0 != diff)
         {
             return diff;
         }
         else
         {
             return x.Id.CompareTo(y.Id);
         }
      }

      /// <summary>
      /// Retrieves the list of all processes matching the Id
      /// parameter and generates a non-terminating error for
      /// each specified process identifier which is not found.
      /// </summary>
      /// <returns>
      /// An array of processes that match the given identifier.
      /// </returns>
      [EnvironmentPermissionAttribute(
         SecurityAction.LinkDemand,
         Unrestricted = true)]
      private List<Process> GetMatchingProcessesById()
      {
         new EnvironmentPermission(
            PermissionState.Unrestricted).Assert();

         List<Process> matchingProcesses = new List<Process>();

         if (null != this.processIds)
         {
            // The keys dictionary is used for rapid lookup of the
            // processes already in the matchingProcesses list.
            Dictionary<int, byte> keys = new Dictionary<int, byte>();

            foreach (int processId in this.processIds)
            {
               WriteVerbose("Finding match for process id "
                  + processId + ".");

               if (!keys.ContainsKey(processId))
               {
                  Process process;
                  try
                  {
                      process = Process.GetProcessById(processId);
                  }
                  catch (ArgumentException ex)
                  {
                     WriteError(new ErrorRecord(
                        ex,
                        "ProcessIdNotFound",
                        ErrorCategory.ObjectNotFound,
                        processId));
                     continue;
                  }

                  WriteDebug("Found matching process.");

                  matchingProcesses.Add(process);
                  keys.Add(processId, 0);
               }
            }
         }

         return matchingProcesses;
      } // GetMatchingProcessesById

      /// <summary>
      /// Retrieves the list of all processes matching the InputObject
      /// parameter.
      /// </summary>
      /// <returns>The matching processes.</returns>
      [EnvironmentPermissionAttribute(
         SecurityAction.LinkDemand,
         Unrestricted = true)]
      private List<Process> GetProcessesByInput()
      {
         new EnvironmentPermission(
            PermissionState.Unrestricted).Assert();

         List<Process> matchingProcesses = new List<Process>();

         if (null != this.Input)
         {
            // The keys dictionary is used for rapid lookup of the
            // processes already in the matchingProcesses list.
            Dictionary<int, byte> keys = new Dictionary<int, byte>();

            foreach (Process process in this.Input)
            {
               WriteVerbose("Refreshing process object.");

               if (!keys.ContainsKey(process.Id))
               {
                  try
                  {
                      process.Refresh();
                  }
                  catch (Win32Exception)
                  {
                  }
                  catch (InvalidOperationException)
                  {
                  }

                  matchingProcesses.Add(process);
               }
            }
         }

         return matchingProcesses;
      } // GetProcessesByInput
      #endregion Private Methods
    } // End GetProcCommand class.

    #endregion GetProcCommand
}

Véase también

• escribir un cmdlet de Windows PowerShell