C#.Net: Why is my Process.Start() hanging?

Question

I'm trying to run a batch file, as another user, from my web app. For some reason, the batch file hangs! I can see "cmd.exe" running in the task manager, but it just sits there forever, unable to be killed, and the batch file is not running. Here's my code:

SecureString password = new SecureString();
foreach (char c in "mypassword".ToCharArray())
    password.AppendChar(c);

ProcessStartInfo psi = new ProcessStartInfo();
psi.WorkingDirectory = @"c:\build";
psi.FileName = Environment.SystemDirectory + @"\cmd.exe";
psi.Arguments = "/q /c build.cmd";
psi.UseShellExecute = false;
psi.UserName = "builder";
psi.Password = password;
Process.Start(psi);

If you didn't guess, this batch file builds my application (a different application than the one that is executing this command).

The Process.Start(psi); line returns immediately, as it should, but the batch file just seems to hang, without executing. Any ideas?

EDIT: See my answer below for the contents of the batch file.

• The output.txt never gets created.

I added these lines:

psi.RedirectStandardOutput = true;
Process p = Process.Start(psi);
String outp = p.StandardOutput.ReadLine();

and stepped through them in debug mode. The code hangs on the ReadLine(). I'm stumped!

Answer 1

I believe I've found the answer. It seems that Microsoft, in all their infinite wisdom, has blocked batch files from being executed by IIS in Windows Server 2003. Brenden Tompkins has a work-around here:

http://codebetter.com/blogs/brendan.tompkins/archive/2004/05/13/13484.aspx

That won't work for me, because my batch file uses IF and GOTO, but it would definitely work for simple batch files.

Answer 2

Why not just do all the work in C# instead of using batch files?

I was bored so i wrote this real quick, it's just an outline of how I would do it since I don't know what the command line switches do or the file paths.

using System;
using System.IO;
using System.Text;
using System.Security;
using System.Diagnostics;

namespace asdf
{
    class StackoverflowQuestion
    {
        private const string MSBUILD = @"path\to\msbuild.exe";
        private const string BMAIL = @"path\to\bmail.exe";
        private const string WORKING_DIR = @"path\to\working_directory";

        private string stdout;
        private Process p;

        public void DoWork()
        {
            // build project
            StartProcess(MSBUILD, "myproject.csproj /t:Build", true);
        }

        public void StartProcess(string file, string args, bool redirectStdout)
        {
            SecureString password = new SecureString();
            foreach (char c in "mypassword".ToCharArray())
                password.AppendChar(c);

            ProcessStartInfo psi = new ProcessStartInfo();
            p = new Process();
            psi.WindowStyle = ProcessWindowStyle.Hidden;
            psi.WorkingDirectory = WORKING_DIR;
            psi.FileName = file;
            psi.UseShellExecute = false;
            psi.RedirectStandardOutput = redirectStdout;
            psi.UserName = "builder";
            psi.Password = password;
            p.StartInfo = psi;
            p.EnableRaisingEvents = true;
            p.Exited += new EventHandler(p_Exited);
            p.Start();

            if (redirectStdout)
            {
                stdout = p.StandardOutput.ReadToEnd();
            }
        }

        void p_Exited(object sender, EventArgs e)
        {
            if (p.ExitCode != 0)
            {
                // failed
                StringBuilder args = new StringBuilder();
                args.Append("-s k2smtpout.secureserver.net ");
                args.Append("-f [email protected] ");
                args.Append("-t [email protected] ");
                args.Append("-a \"Build failed.\" ");
                args.AppendFormat("-m {0} -h", stdout);

                // send email
                StartProcess(BMAIL, args.ToString(), false);
            }
        }
    }
}