Service hangs up at WaitForExit after calling batch file

Question

I have a service that sometimes calls a batch file. The batch file takes 5-10 seconds to execute:

System.Diagnostics.Process proc = new System.Diagnostics.Process(); // Declare New Process
    proc.StartInfo.FileName = fileName;
    proc.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
    proc.StartInfo.CreateNoWindow = true;
    proc.Start();
    proc.WaitForExit();

The file does exist and the code works when I run the same code in-console. However when it runs inside the service, it hangs up at WaitForExit(). I have to kill the batch file from the Process in order to continue. (I am certain the file exists, as I can see it in the processes list.)

How can I fix this hang-up?

Update #1:

Kevin's code allows me to get output. One of my batch files is still hanging.

"C:\EnterpriseDB\Postgres\8.3\bin\pg_dump.exe" -i -h localhost -p 5432 -U postgres -F p -a -D -v -f "c:\backupcasecocher\backupdateevent2008.sql" -t "\"public\".\"dateevent\"" "DbTest"

The other batch file is:

"C:\EnterpriseDB\Postgres\8.3\bin\vacuumdb.exe" -U postgres -d DbTest

I have checked the path and the postgresql path is fine. The output directory does exist and still works outside the service. Any ideas?

Update #2:

Instead of the path of the batch file, I wrote the "C:\EnterpriseDB\Postgres\8.3\bin\pg_dump.exe" for the proc.StartInfo.FileName and added all parameters to proc.StartInfo.Arguments. The results are unchanged, but I see the pg_dump.exe in the process window. Again this only happens inside the service.

Update #3:

I have run the service with a user in the administrator group, to no avail. I restored null for the service's username and password

Update #4:

I created a simple service to write a trace in the event log and execute a batch file that contains "dir" in it. It will now hang at proc.Start(); - I tried changing the Account from LocalSystem to User and I set the admnistrator user and password, still nothing.

Solution 1

Here is what i use to execute batch files:

proc.StartInfo.FileName                 = target;
proc.StartInfo.RedirectStandardError    = true;
proc.StartInfo.RedirectStandardOutput   = true;
proc.StartInfo.UseShellExecute          = false;

proc.Start();

proc.WaitForExit
    (
        (timeout <= 0)
            ? int.MaxValue : timeout * NO_MILLISECONDS_IN_A_SECOND *
                NO_SECONDS_IN_A_MINUTE
    );

errorMessage = proc.StandardError.ReadToEnd();
proc.WaitForExit();

outputMessage = proc.StandardOutput.ReadToEnd();
proc.WaitForExit();

I don't know if that will do the trick for you, but I don't have the problem of it hanging.

Solution 2

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Diagnostics;
    namespace VG
    {
        class VGe
        {
            [STAThread]
            static void Main(string[] args)
            {
                Process proc = null;
                try
                {                
                    string targetDir = string.Format(@"D:\adapters\setup");//this is where mybatch.bat lies
                    proc = new Process();
                    proc.StartInfo.WorkingDirectory = targetDir;
                    proc.StartInfo.FileName = "mybatch.bat";
                    proc.StartInfo.Arguments = string.Format("10");//this is argument
                    proc.StartInfo.CreateNoWindow = false;
                    proc.Start();
                    proc.WaitForExit();
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Exception Occurred :{0},{1}", ex.Message,ex.StackTrace.ToString());
                }
            }
        }
    }

Solution 3

            string targetDir = string.Format(@"D:\");//PATH
            proc = new Process();
            proc.StartInfo.WorkingDirectory = targetDir;
            proc.StartInfo.FileName = "GetFiles.bat";
            proc.StartInfo.Arguments = string.Format("10");//argument
            proc.StartInfo.CreateNoWindow = false;
            proc.Start();
            proc.WaitForExit();

Tested,works clear.

Solution 4

The next step I would take is to fire up the debugger, and see if you can tell what the program is waiting on. If you are expierenced at debugging in assembly, you may be able to get an IDEA of what's happening using tools like ProcExp, FileMon, etc.

Being a windows SERVICE, and not a web service, makes quite a bit of difference. Anyways, have you tried my suggestion of setting the "Allow Service to interact with desktop"?

If you are desperate, you might try launching cmd.exe instead of your batch file. Then, using the cmd.exe's cmd line parameters, you can have IT start the batch file. This would probably give you a cmd prompt window to view the actual output, if you turn on the interact with desktop.

For complete help on cmd.exe, just type cmd /? at any command prompt.

Larry

Solution 5

pg_dump.exe is probably prompting for user input. Does this database require authentication? Are you relying on any ENVIRONMENT variables that won't be present for the service? I don't know pg_dump but what are the other possible reasons it would prompt for input?

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