.NET Diagnostics - III, Enumerate System Services and Dependencies Using C#

• Download demo project for .NET beta 1/2 - 6 Kb

Introduction

Continuing in the series of writing some diagnostics tools and exploring the System.Diagnostics namespace; this article shows how do you find out what all system services are running on the system and most importantly finding their dependencies. It's the later part that I found very interesting. Every time I open the Services dialog box or Task Manager on my system to look what all services are running, I used to think what will happen if I shut down one of them to recover some resources. But then you have to think, what if this service is part of some other service or application running on the system. This utility application enumerates and displays all the system services running on a system. And it also lists all the services a particular service is dependent upon and the services that depend on this service.

How do you do it?

The .NET framework provides the System.ServiceProcess namespace. This namespace contains classes for installing and running system services. In this namespace, you will find a class named SystemController. A SystemController is nothing but a System Service in NT lingo. This class has a static method GetServices() that returns an array of SystemController objects. This array contains all the services running on a system.

ServiceController [] controllers = 
    ServiceController.GetServices();

After you have obtained this array, enumerate through each element to get details about each service. The SystemController class has a bunch of properties and their names are self-explanatory. I will not go into details of each property. I would suggest you to look in framework documentation for more details.

• DisplayName - The descriptive name shown for this service in the Service applet.
• Status - Status of the service e.g., Running, Stopped, etc.
• ServiceType - Type of service that object references.
• ServiceName  Short name of the service.
• CanStop - Indicates if the service can be stopped at any time.
• CanShutDown - Indicates if the service can be shut down any time.
• CanPauseAndContinue - If the service can be stopped and continued.
• DependentServices - List of services that depend on this service.
• ServicesDependOn - List of services that this service depends on.

The ServiceController class has a couple of methods that can be used to start and stop a service. I have not shown the use of these methods in this utility project. But they are pretty simple to use.

Look at the InitList method in the source code attached with this article. This function shows how to use all the properties of the SystemController class.

// Check the status of this service to see if 

// it can be stopped

bool bCanStop = controllers[i].CanStop;
item.SetSubItem(3, bCanStop ? "Yes" : "No");

// Check if the service recieves notification when 

// system shuts down.

bool bCanShutDown = controllers[i].CanShutdown;
item.SetSubItem(4, bCanShutDown ? "Yes" : "No");

// Check if the service can be paused and continued.

bool bPauseNContinue = controllers[i].CanPauseAndContinue;
item.SetSubItem(5, bPauseNContinue ? "Yes" : "No");