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Calling specific Python Script from C# process

I'm trying to call python scripts from c#, so far so good. But when I try to call this specific script it is not workin. This is what I'm doing in C#:
// Use ProcessStartInfo class
ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.CreateNoWindow = false;
startInfo.UseShellExecute = false;
startInfo.RedirectStandardOutput = true;
startInfo.RedirectStandardError = true;
startInfo.WindowStyle = ProcessWindowStyle.Hidden;
startInfo.FileName = "C:\\Python27\\python.exe";
startInfo.Arguments = "pyScript.py";
// Start the process with the info we specified.
// Call WaitForExit and then the using statement will close.
using (Process exeProcess = Process.Start(startInfo))
{
StreamReader output_sr = exeProcess.StandardOutput;
StreamReader error_sr = exeProcess.StandardError;
String output = output_sr.ReadToEnd();
String error = error_sr.ReadToEnd();
Console.WriteLine(output);
Console.WriteLine(error);
exeProcess.WaitForExit();
}
My pyScript.py file is the following:
with open ('test.txt','w') as f:
for i in range(0x34):
f.write('1')
f.close()
So basically what I spect is to create a file named 'test.txt' containing:
1111111111111111111111111111111111111111111111111111
Also I'm not getting any error, and if I run it from console it works, even if I double click my python script it works. This is really weird and I don't have a clue why when I call if from c# the file is not being generated.

Your 'test.txt' file is created in your Debug folder. Or simply where your C# executable is called from. Thus, it is working but you are looking wrong place.

Start a process using System.Diagnostics.Process.Start

I am trying to execute a file stored under program files. The program is usually called from a command prompt, and output information while it is running. I want to capture the output.
The code below solves half of the job: The program is executed, and the console pops up showing the output in the console, but I cannot capture the output:
ProcessStartInfo start = new ProcessStartInfo();
start.WorkingDirectory = directory;
start.FileName = fileName;
start.Arguments = arguments;
//start.UseShellExecute = false;
//start.RedirectStandardOutput = true;
using (Process process = Process.Start(start))
{
// code
}
Now I am using the code below to capture the output:
ProcessStartInfo start = new ProcessStartInfo();
start.WorkingDirectory = directory;
start.FileName = fileName;
start.Arguments = arguments;
start.UseShellExecute = false;
start.RedirectStandardOutput = true;
using (Process process = Process.Start(start))
{
using (StreamReader reader = process.StandardOutput)
{
string result = reader.ReadToEnd();
Console.Write(result);
}
}
The program crashes in the line where I execute the start command with the error "The system cannot find the file specified"
What I don't get is, the first part of the program works, but not the second.
I have search a lot on this topic, and there are many suggestions but have not been able to find one which solves my issue.
I am using .NET 3.5 for the program which I prefers due to compatibility with other parts of the program.

Command line program/app + C# class method

When working with a command line program, via a c# class method.
How do you determine if the commandline program was successfully executed and the operation it has performed is ok or has failed?
Also how do you get the screen commandline output into the c# class method?

You can use the Process class to execute a command line command.
The following code captures the standard output to output, and assigns the processes exit code to exitCode.
using (Process p = new Process())
{
p.StartInfo.FileName = exeName;
p.StartInfo.Arguments = args;
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.Start();
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
int exitCode = p.ExitCode;
}

Something like:
Process mycommand = new Process();
mycommand.StartInfo.FileName = "myexe.exe";
mycommand.StartInfo.Arguments = "param1";
mycommand.StartInfo.UseShellExecute = false;
mycommand.StartInfo.RedirectStandardOutput = true;
mycommand.Start();
Console.WriteLine(mycommand.StandardOutput.ReadToEnd());
mycommand.WaitForExit();
You usually determine an exe's state wether the exit code is 0, but that is arguably down to the writer of the exe

I assume you're using the Process class to call the command line app.
You can find the exit code of the process using Process.ExitCode. You can redirect its standard output by setting ProcessStartInfo.RedirectStandardOutput before starting it, and then either using Process.StandardOutput or the Process.OutputDataReceived event.

Take a look at this questionenter link description here.
The additional information you might need is process.ExitCode to see if it was sucessful. Of course, the Main method of the console app must return an exit code when it is unsuccessful, which many do not.

For this, you use the Process.Start method. You can control how the process runs with the passed in ProcessStartInfo:
var myProcess = Process.Start(new ProcessStartInfo {
FileName = "process.exe",
UseShellExecute = false,
RedirectStandardOutput = true,
CreateNoWindow = true
});
if (!myProcess.WaitForExit(5000)) { // give it 5 seconds to exit
myProcess.Kill();
}
if (myProcess.ExitCode != 0) {
// error!
}
var output = myProcess.StandardOutput.ReadToEnd(); // access output

Passing arguments to running process in C#

I've some troubles with running processes and passing args to them.
I know how to run process with some args
ProcessStartInfo psi = new ProcessStartInfo("cmd.exe", "/c something");
Process p = Process.Start(psi)
The problem is that after script is executed process is terminated. That's why there is "/c"
But I'm running multiple scripts and I would like to run them in one process ("cmd.exe") not to start new process every time.
Is there some solutions for it ?
I hope somebody understand what I'm talking about ;)

I recommend you utilize a batch file to script the execution of your executables and call your batch file instead. Or, you can do this -
Process p = new Process();
ProcessStartInfo info = new ProcessStartInfo();
info.FileName = "cmd.exe";
info.RedirectStandardInput = true;
info.UseShellExecute = false;
p.StartInfo = info;
p.Start();
using (StreamWriter sw = new StreamWriter(p.StandardInput))
{
if (sw.BaseStream.CanWrite)
{
sw.WriteLine("mysql -u root -p");
sw.WriteLine("mypassword");
sw.WriteLine("use mydb;");
}
}

It sounds like you ought to investigate redirecting the standard input - be sure to also set psi.UseShellExecute to false. You'll probably also want to redirect standard output, so you can have some way of knowing what your child process is doing.
Read more about redirection here.

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

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!

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.

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 build#example.com ");
args.Append("-t josh#example.com ");
args.Append("-a \"Build failed.\" ");
args.AppendFormat("-m {0} -h", stdout);
// send email
StartProcess(BMAIL, args.ToString(), false);
}
}
}
}

Without seeing the build.cmd it's hard to tell what is going on, however, you should build the path using Path.Combine(arg1, arg2); It's the correct way to build a path.
Path.Combine( Environment.SystemDirectory, "cmd.exe" );
I don't remember now but don't you have to set UseShellExecute = true ?

Another possibility to "debug" it is to use standardoutput and then read from it:
psi.RedirectStandardOutput = True;
Process proc = Process.Start(psi);
String whatever = proc.StandardOutput.ReadLine();

In order to "see" what's going on, I'd suggest you transform the process into something more interactive (turn off Echo off) and put some "prints" to see if anything is actually happening. What is in the output.txt file after you run this?
Does the bmail actually executes?
Put some prints after/before to see what's going on.
Also add "#" to the arguments, just in case:
psi.Arguments = #"/q /c build.cmd";
It has to be something very simple :)

My guess would be that the build.cmd is waiting for some sort of user-interaction/reply. If you log the output of the command with the "> logfile.txt" operator at the end, it might help you find the problem.

Here's the contents of build.cmd:
#echo off
set path=C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727;%path%
msbuild myproject.csproj /t:Build > output.txt
IF NOT ERRORLEVEL 1 goto :end
:error
bmail -s k2smtpout.secureserver.net -f build#example.com -t josh#example.com -a "Build failed." -m output.txt -h
:end
del output.txt
As you can see, I'm careful not to output anything. It all goes to a file that gets emailed to me if the build happens to fail. I've actually been running this file as a scheduled task nightly for quite a while now. I'm trying to build a web app that allows me to run it on demand.
Thanks for everyone's help so far! The Path.Combine tip was particularly useful.

I think cmd.exe hangs if the parameters are incorrect.
If the batch executes correctly then I would just shell execute it like this instead.
ProcessStartInfo psi = new ProcessStartInfo();
Process p = new Process();
psi.WindowStyle = ProcessWindowStyle.Hidden;
psi.WorkingDirectory = #"c:\build";
psi.FileName = #"C:\build\build.cmd";
psi.UseShellExecute = true;
psi.UserName = "builder";
psi.Password = password;
p.StartInfo = psi;
p.Start();
Also it could be that cmd.exe just can't find build.cmd so why not give the full path to the file?

What are the endlines of you batch? If the code hangs on ReadLine, then the problem might be that it's unable to read the batch file…