How to run console application from Windows Servic

Question

I have a windows service, written in c# and I need to run a console application from it. Console application also written in c#.

Console application is running fine when it is run not from windows service. When it is ran from ws it doesn`t do anything it should and as it should work for 10-20 seconds I see in debug code is executed at once.

I`m starting my console app with the following code:

proc.Start(fullPathToConsole, args);
proc.WaitForExit();

the path to console is right and when I`m trying to run it from the cmd or just in explorer (without args) it works fine. But after running with the service I see no effect.

I already tried to go to service properties and give it access to desktop and run under both system and my user (also specified in service properties). All remains the same.

ADDITION: I know service do not have ui and I don't want one. I want service to run console application. No need to get any data from it or use this console like ui, just run it to do it`s job.

UPDATE I: discovered, that running calc or any other windows app is easy. But still can`t run cmd or any console app. Actually I need to run it on XP SP2 and Windows 2003 Server. So do not need to interact with Vista in anyway.

Would be glad to any comments!

Answer 1

I have a Windows service, and I added the following line to the constructor for my service:

using System.Diagnostics;
try {
    Process p = Process.Start(@"C:\Windows\system32\calc.exe");
} catch {
    Debugger.Break();
}

When I tried to run this, the Process.Start() call was made, and no exception occurred. However, the calc.exe application did not show up. In order to make it work, I had edit the properties for my service in the Service Control Manager to enable interaction with the desktop. After doing that, the Process.Start() opened calc.exe as expected.

But as others have said, interaction with the desktop is frowned upon by Microsoft and has essentially been disabled in Vista. So even if you can get it to work in XP, I don't know that you'll be able to make it work in Vista.

Answer 2

I've done this before successfully - I have some code at home. When I get home tonight, I'll update this answer with the working code of a service launching a console app.

I thought I'd try this from scratch. Here's some code I wrote that launches a console app. I installed it as a service and ran it and it worked properly: cmd.exe launches (as seen in Task Manager) and lives for 10 seconds until I send it the exit command. I hope this helps your situation as it does work properly as expected here.

    using (System.Diagnostics.Process process = new System.Diagnostics.Process())
    {
        process.StartInfo = new System.Diagnostics.ProcessStartInfo(@"c:\windows\system32\cmd.exe");
        process.StartInfo.CreateNoWindow = true;
        process.StartInfo.ErrorDialog = false;
        process.StartInfo.RedirectStandardError = true;
        process.StartInfo.RedirectStandardInput = true;
        process.StartInfo.RedirectStandardOutput = true;
        process.StartInfo.UseShellExecute = false;
        process.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
        process.Start();
        //// do some other things while you wait...
        System.Threading.Thread.Sleep(10000); // simulate doing other things...
        process.StandardInput.WriteLine("exit"); // tell console to exit
        if (!process.HasExited)
        {
            process.WaitForExit(120000); // give 2 minutes for process to finish
            if (!process.HasExited)
            {
                process.Kill(); // took too long, kill it off
            }
        }
    }

Answer 3

Starting from Windows Vista, a service cannot interact with the desktop. You will not be able to see any windows or console windows that are started from a service. See this MSDN forum thread.

On other OS, there is an option that is available in the service option called "Allow Service to interact with desktop". Technically, you should program for the future and should follow the Vista guideline even if you don't use it on Vista.

If you still want to run an application that never interact with the desktop, try specifying the process to not use the shell.

ProcessStartInfo info = new ProcessStartInfo(@"c:\myprogram.exe");
info.UseShellExecute = false;
info.RedirectStandardError = true;
info.RedirectStandardInput = true;
info.RedirectStandardOutput = true;
info.CreateNoWindow = true;
info.ErrorDialog = false;
info.WindowStyle = ProcessWindowStyle.Hidden;

Process process = Process.Start(info);

See if this does the trick.

First you inform Windows that the program won't use the shell (which is inaccessible in Vista to service).

Secondly, you redirect all consoles interaction to internal stream (see process.StandardInput and process.StandardOutput.

Answer 4

As pierre said, there is no way to have a user interface for a windows service (or no easy way). What I do in that kind of situation is to have a settings file that is read from the service on whatever interval the service operates on and have a standalone application that makes changes to the settings file.

Answer 5

Services are required to connect to the Service Control Manager and provide feedback at start up (ie. tell SCM 'I'm alive!'). That's why C# application have a different project template for services. You have two alternatives:

• wrapp your exe on srvany.exe, as described in KB How To Create a User-Defined Service
• have your C# app detect when is launched as a service (eg. command line param) and switch control to a class that inherits from ServiceBase and properly implements a service.

Answer 6

Windows Services do not have UIs. You can redirect the output from a console app to your service with the code shown in this question.