Pablo Galiano : Creating a PowerShell cmdlet

Creating a PowerShell cmdlet

Some time ago kzu told me about a shell extension called CleanSources, the purpose of this application is to recursive delete all the files and folders under the \bin and \obj directories for a given path.

This tool is very usefull if we dont want to open a Visual Studio and do a Clean Solution/Project for every source code that we want to clean.

So, based on this idea I will create a PowerShell cmdlet to replicate that functionality.

These are the detailed steps:

Create a Visual Studio project:

Create a class library project and add a reference to System.Managment.Automation.dll located at %programfiles%/Windows PowerShell\v1.0 and to System.Configuration.Install.dll

Create the cmdlet class:

    [Cmdlet(VerbsCommon.Remove, "Binaries")]
    public class CleanerCmdLet : PSCmdlet
    {
    }

Add the cmdlet parameter:

        private string basePath;
 
        [Parameter(Mandatory = true, Position = 0)]
        public string BasePath
        {
            get { return basePath; }
            set { basePath = value; }
        }

Implement the cmdlet functionality:

        protected override void ProcessRecord()
        {
            CleanSubDirectory(this.basePath);
        }
 
        private void CleanSubDirectory(string path)
        {
            foreach(string subDirectory in Directory.GetDirectories(path))
            {
                DirectoryInfo info = new DirectoryInfo(subDirectory);
 
                if(info.Name.ToLower().Equals("bin") || info.Name.ToLower().Equals("obj"))
                {
                    try
                    {
                        info.Delete(true);
                    }
                    catch(UnauthorizedAccessException)
                    {
                        //Do nothing if the file is readonly
                    }
                }
                else
                {
                    CleanSubDirectory(subDirectory);
                }
            }
        }

Create the snap-in class:

						using System;

						using System.Collections.Generic;

						using System.Text;

						using System.Management.Automation;

						using System.Management.Automation.Runspaces;

						using System.Collections.ObjectModel;

						using System.ComponentModel;
 
    [RunInstaller(true)]
    public class RemoveBinariesPSSnapIn : CustomPSSnapIn
    {
        private Collection<CmdletConfigurationEntry> cmdlets = new Collection<CmdletConfigurationEntry>();
        private Collection<ProviderConfigurationEntry> providers = new Collection<ProviderConfigurationEntry>();
        private Collection<TypeConfigurationEntry> types = new Collection<TypeConfigurationEntry>();
        private Collection<FormatConfigurationEntry> formats = new Collection<FormatConfigurationEntry>();
 
        public RemoveBinariesPSSnapIn()
            : base()
        {
            cmdlets.Add(new CmdletConfigurationEntry("remove-binaries", typeof(CleanerCmdLet), null));
        }
 
        public override string Name
        {
            get { return "RemoveBinariesPSSnapIn"; }
        }
 
        public override string Vendor
        {
            get { return "Clarius Consulting"; }
        }
 
        public override string Description
        {
            get { return "This snap-in contains the Remove Binaries cmdlet."; }
        }
 
        public override Collection<CmdletConfigurationEntry> Cmdlets
        {
            get { return cmdlets; }
        }
 
        public override Collection<ProviderConfigurationEntry> Providers
        {
            get { return providers; }
        }
 
        public override Collection<TypeConfigurationEntry> Types
        {
            get { return types; }
        }
 
        public override Collection<FormatConfigurationEntry> Formats
        {
            get { return formats; }
        }
 
    }