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

Naveen K Kohli

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18 Mar 2001

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How to get the list of all system services on a system and also finds out their dependencies.

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");

License

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Written By

Naveen K Kohli

United States

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Comments and Discussions

My vote of 1

dudeua7-Dec-08 22:23

dudeua

7-Dec-08 22:23

Doesn't compile at all

Process Id ?

Alexis MICHEL16-Oct-07 5:10

Alexis MICHEL

16-Oct-07 5:10

Is there any way to get the process Id from a ServiceController class (or a ServiceHandle) ?

"Marriage is the triumph of imagination over intelligence. Second marriage is the triumph of hope over experience"
--Oscar Wilde

automatic and manual

jarellan12-Sep-07 23:40

jarellan

12-Sep-07 23:40

First of all, thank you very much for the effort of making the tutorial.

I haven't seen any property/method to set the service in automatic/manual mode, like in the property window of Services in the Administrative tools of windows. Anyone know how to do that?

Regards.

Re: automatic and manual

AaronM_NZ27-Oct-07 15:19

AaronM_NZ

27-Oct-07 15:19

If you havent figured this out, let me know, I have done it, its not easy though!

Re: automatic and manual

gmooney26-Mar-08 5:37

gmooney

26-Mar-08 5:37

Hi, could you show me a copy of the code or point to where I might find how to alter a service to manual.
Many thanks

Re: automatic and manual

AaronM_NZ7-Apr-08 0:57

AaronM_NZ

7-Apr-08 0:57

There is a bit involved, you need to open the service manager, then the service, and then perform the changes required. The Microsoft MSDN libray is handy - if you know C++ - http://msdn2.microsoft.com/en-us/library/ms681987.aspx[^]

Here is a bit of code I have put together, to change the basic parameters on the service using the ChangeServiceConfig API. You need to call the ChangeSVCConfig function with the host name, service name (not the display name), executable path, and the start type. You should be able to pick it apart to change just the start type. I was primarily interesting in changing the binary path.

Just note the actual call to the API is looking for Form1 in this example, change this to the name of your class. And youll need a Imports System.Runtime.InteropServices in you class definition.

This code isnt pretty, but it works. Its a cut and paste from a couple of different projects I have been working on, hopefully it does what you need!

Public Declare Function ChangeServiceConfig Lib "advapi32.dll" Alias "ChangeServiceConfigA" (ByVal hService As Integer, ByVal dwServiceType As svType, ByVal dwStartType As svStartType, ByVal dwErrorControl As svErrorControl, ByVal lpBinaryPathName As String, ByVal lpLoadOrderGroup As String, ByVal lpdwTagId As Integer, ByVal lpDependencies As String, ByVal lpServiceStartName As String, ByVal lpPassword As String, ByVal lpDisplayName As String) As Boolean<br />
    Public Declare Function OpenSCManager Lib "advapi32.dll" Alias "OpenSCManagerA" (ByVal lpMachineName As String, ByVal lpDatabaseName As String, ByVal dwDesiredAccess As Integer) As Integer<br />
    Public Declare Function OpenService Lib "advapi32.dll" Alias "OpenServiceA" (ByVal hSCManager As Integer, ByVal lpServiceName As String, ByVal dwDesiredAccess As Integer) As Integer<br />
<br />
    Public Declare Function QueryServiceConfig Lib "advapi32.dll" Alias "QueryServiceConfigA" (ByVal hService As Integer, <MarshalAs(UnmanagedType.Struct)> ByRef lpServiceConfig As QUERY_SERVICE_CONFIG, ByVal cbBufSize As Integer, ByVal pcbBytesNeeded As Integer) As Boolean<br />
    Public Declare Function CloseServiceHandle Lib "advapi32.dll" (ByVal hSCObject As Integer) As Long<br />
<br />
    Public Const SERVICE_NO_CHANGE = &HFFFFFFFF<br />
<br />
    Public Const SC_MANAGER_CONNECT = 1<br />
    Public Const STANDARD_RIGHTS_REQUIRED = &HF0000<br />
    Public Const SC_MANAGER_CREATE_SERVICE = &H2<br />
    Public Const SC_MANAGER_ENUMERATE_SERVICE = &H4<br />
    Public Const SC_MANAGER_LOCK = &H8<br />
    Public Const SC_MANAGER_QUERY_LOCK_STATUS = &H10<br />
    Public Const SC_MANAGER_MODIFY_BOOT_CONFIG = &H20<br />
    Public Const SERVICE_CHANGE_CONFIG = 2<br />
<br />
    Public Const SC_MANAGER_ALL_ACCESS = (STANDARD_RIGHTS_REQUIRED Or SC_MANAGER_CONNECT Or SC_MANAGER_CREATE_SERVICE Or SC_MANAGER_ENUMERATE_SERVICE Or SC_MANAGER_LOCK Or SC_MANAGER_QUERY_LOCK_STATUS Or SC_MANAGER_MODIFY_BOOT_CONFIG)<br />
<br />
    <StructLayout(LayoutKind.Sequential)> _<br />
 Public Structure QUERY_SERVICE_CONFIG<br />
        Public dwServiceType As Integer<br />
        Public dwStartType As Integer<br />
        Public dwErrorControl As Integer<br />
        <MarshalAs(UnmanagedType.LPWStr)> Public pBinaryPathName As String<br />
        <MarshalAs(UnmanagedType.LPWStr)> Public pLoadOrderGroup As String<br />
        Public dwTagId As Integer<br />
        <MarshalAs(UnmanagedType.LPWStr)> Public pDependencies As String<br />
        <MarshalAs(UnmanagedType.LPWStr)> Public pServiceStartName As String<br />
        <MarshalAs(UnmanagedType.LPWStr)> Public pDisplayName As String<br />
    End Structure<br />
<br />
    Public Structure SERVICE_STATUS<br />
        Dim dwServiceType As Integer<br />
        Dim dwCurrentState As Integer<br />
        Dim dwControlsAccepted As Integer<br />
        Dim dwWin32ExitCode As Integer<br />
        Dim dwServiceSpecificExitCode As Integer<br />
        Dim dwCheckPoint As Integer<br />
        Dim dwWaitHint As Integer<br />
    End Structure<br />
<br />
    Public Enum svType As Integer<br />
        SERVICE_KERNEL_DRIVER = &H1<br />
        SERVICE_FILE_SYSTEM_DRIVER = &H2<br />
        SERVICE_WIN32_OWN_PROCESS = &H10<br />
        SERVICE_WIN32_SHARE_PROCESS = &H20<br />
        SERVICE_INTERACTIVE_PROCESS = &H100<br />
        SERVICETYPE_NO_CHANGE = SERVICE_NO_CHANGE<br />
    End Enum<br />
    Public Enum svStartType As Integer<br />
        SERVICE_BOOT_START = &H0<br />
        SERVICE_SYSTEM_START = &H1<br />
        SERVICE_AUTO_START = &H2<br />
        SERVICE_DEMAND_START = &H3<br />
        SERVICE_DISABLED = &H4<br />
        SERVICESTARTTYPE_NO_CHANGE = SERVICE_NO_CHANGE<br />
    End Enum<br />
    Public Enum svErrorControl As Integer<br />
        SERVICE_ERROR_IGNORE = &H0<br />
        SERVICE_ERROR_NORMAL = &H1<br />
        SERVICE_ERROR_SEVERE = &H2<br />
        SERVICE_ERROR_CRITICAL = &H3<br />
        SERVICEERRORCONTROL_NO_CHANGE = SERVICE_NO_CHANGE<br />
    End Enum<br />
<br />
    Public Structure QUERY_SERVICE_LOCK_STATUS<br />
        Dim fIsLocked As Long<br />
        Dim lpLockOwner As String<br />
        Dim dwLockDuration As Long<br />
    End Structure<br />
<br />
    ''' <summary>Calls Windows ChangeServiceConfig API to change a service configuration</summary><br />
    ''' <param name="strMachineName">The computer name</param><br />
    ''' <param name="strServiceName">The windows service name</param><br />
    ''' <param name="strBinPath">The path to the service executable</param><br />
    ''' <param name="intStartType">Integer representing the start type<br />
    ''' 0 = No Change  <br />
    ''' 2 = Automatic  <br />
    ''' 3 = Manual     <br />
    ''' 4 = Disabled</param><br />
    ''' <returns>True for update success, false for failure. Call LastDllError for error information</returns><br />
    ''' <remarks></remarks><br />
    Public Function ChangeSVCConfig(ByVal strMachineName As String, ByVal strServiceName As String, ByVal strBinPath As String, ByVal intStartType As Integer) As Boolean<br />
<br />
        Dim hSCM As Integer<br />
        Dim hSVC As Integer<br />
<br />
        hSCM = OpenSCManager(strMachineName, vbNullString, SC_MANAGER_ALL_ACCESS)<br />
        If hSCM = 0 Then Exit Function<br />
<br />
        hSVC = OpenService(hSCM, strServiceName, SERVICE_CHANGE_CONFIG)<br />
        If hSVC = 0 Then Exit Function<br />
<br />
        Dim svType As svStartType<br />
        Select Case intStartType<br />
            Case 2<br />
                svType = svStartType.SERVICE_AUTO_START<br />
            Case 3<br />
                svType = svStartType.SERVICE_DEMAND_START<br />
            Case 4<br />
                svType = svStartType.SERVICE_DISABLED<br />
            Case Else<br />
                svType = svStartType.SERVICESTARTTYPE_NO_CHANGE<br />
        End Select<br />
<br />
        Try<br />
            ChangeSVCConfig = ChangeServiceConfig(hSVC, Form1.svType.SERVICETYPE_NO_CHANGE, svType, svErrorControl.SERVICEERRORCONTROL_NO_CHANGE, strBinPath, vbNullString, vbNullString, vbNullString, vbNullString, vbNullString, vbNullString)<br />
        Finally<br />
            CloseServiceHandle(hSVC)<br />
            CloseServiceHandle(hSCM)<br />
        End Try<br />
<br />
    End Function

where's the form ?

Harkamal Singh12-Jul-07 0:56

Harkamal Singh

12-Jul-07 0:56

uploaded project does'nt has the Form module !! Cry | :((

how to get image path

Harkamal Singh12-Jul-07 0:52

Harkamal Singh

12-Jul-07 0:52

how to get image path for a service ?

Either we can read registry value or use WMI, in which case C# has no built in features ?
Sigh | :sigh:

How to implement in VC

Prateeti22-Aug-02 18:54

Prateeti

22-Aug-02 18:54

The functionality which you have suggested, Is it possible to implement in VC6.0?

Stop time

19-Mar-01 15:25

Dynamic extend the amount of time the service has to exit without an error (default is 30 seconds)?

How to dynamic make a service interact with the desktop?

19-Mar-01 15:21

Thanks, Italo S Weiss.

Re: How to dynamic make a service interact with the desktop?

n4nilesh23-Aug-04 8:30

n4nilesh

23-Aug-04 8:30

Hi
I have done this using WMI and it is working for me fine.
please look at the WMI class Win32_Service and its Change method. there is a "IN" attribute named "DesktopInteract".
you can make it true or false based on your rquirement.

please let me know if there is some confusion.

Nilesh

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