Develop Reference

How to redirect command prompt output to a file using asp.net C#?

I have tried to redirect the command prompt output to a file using Asp.Net C#.
System.Diagnostics.Process si = new System.Diagnostics.Process();
si.StartInfo.WorkingDirectory = "c:\\";
si.StartInfo.UseShellExecute = false;
si.StartInfo.FileName = "cmd.exe";
si.StartInfo.Arguments = #"/c dir" +">" + #"Myval.txt";
si.StartInfo.CreateNoWindow = true;
si.StartInfo.RedirectStandardInput = true;
si.StartInfo.RedirectStandardOutput = true;
si.StartInfo.RedirectStandardError = true;
si.Start();
string output = si.StandardOutput.ReadToEnd();
Response.Write(output);
si.Close();
The file is getting created successfully but no content present in it.
Even the variable Output returns nothing.
Help me to resolve this issue.

EDIT after being corrected:
I just tested on my machine and the code works perfectly. I apologize for not reading and testing carefully myself. Myval.txt is created and the DIR output is written into it.
The output variable is empty because you are rerouting any output by the DIR command into the txt file, so that's by design.
Please see if there are any locks on the txt file preventing it from being overwritten. Further than that, I can only guess that there is a security issue preventing the DIR command from running.

IIS7 - I tested this various ways including using a Batch file but the application isn't available on desktop. I can see the worker process and the exe running under my user name but with session id value of zero.

The following has worked for me through command prompt:
// Start the child process.
Process p = new Process();
// Redirect the output stream of the child process.
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.FileName = "YOURBATCHFILE.bat";
p.Start();
// Do not wait for the child process to exit before
// reading to the end of its redirected stream.
// p.WaitForExit();
// Read the output stream first and then wait.
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();

Passing arguments one by one one in console exe by c# code

I want to run an exe file by my c# code. The exe file is a console application written in c#.
The console application performs some actions which includes writing content in database and writing some files to directory.
The console application (exe file) expects some inputs from user.
Like it first asks , 'Do you want to reset database ?' y for yes and n for no.
again if user makes a choice then application again asks , 'do you want to reset files ?'
y for yes and n for no.
If user makes some choice the console application starts to get executed.
Now I want to run this exe console application by my c# code. I am trying like this
string strExePath = "exe path";
ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.CreateNoWindow = false;
startInfo.UseShellExecute = false;
startInfo.FileName = strExePath;
startInfo.WindowStyle = ProcessWindowStyle.Hidden;
using (Process exeProcess = Process.Start(startInfo))
{
exeProcess.WaitForExit();
}
I want to know how can I provide user inputs to the console application by my c# code?
Please help me out in this. Thanks in advance.

You can redirect input and output streams from your exe file.
See redirectstandardoutput
and redirectstandardinput for examples.
For reading:
// Start the child process.
Process p = new Process();
// Redirect the output stream of the child process.
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.FileName = "Write500Lines.exe";
p.Start();
// Do not wait for the child process to exit before
// reading to the end of its redirected stream.
// p.WaitForExit();
// Read the output stream first and then wait.
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
For writing:
...
myProcess.StartInfo.RedirectStandardInput = true;
myProcess.Start();
StreamWriter myStreamWriter = myProcess.StandardInput;
myStreamWriter.WriteLine("y");
...
myStreamWriter.Close();

ProcessStartInfo has a constructor that you can pass arguments to:
public ProcessStartInfo(string fileName, string arguments);
Alternatively, you can set it on it's property:
ProcessStartInfo p = new ProcessStartInfo();
p.Arguments = "some argument";

Here is a sample of how to pass arguments to the *.exe file:
Process p = new Process();
// Redirect the error stream of the child process.
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.FileName = #"\filepath.exe";
p.StartInfo.Arguments = "{insert arguments here}";
p.Start();
error += (p.StandardError.ReadToEnd());
p.WaitForExit();

How to run doxygen from C# and pass in config through stdin?

Doxygen provides a way to pass in the contents of the .doxy file through stdin rather than passing a file name, but I don't know how to do it from C#.
For simplicity let's say the contents of my doxygen config file are simply stored in string[] lines so I want to execute doxygen.exe and feed this content in.

I got this working myself from the links mentioned in the comments, something along the lines of:
// Prepare the process to run
ProcessStartInfo start = new ProcessStartInfo();
// Enter in the command line arguments, everything you would enter after the executable name itself
start.Arguments = " -";
// Enter the executable to run, including the complete path
start.FileName = "doxygen.exe";
// Do you want to show a console window?
start.WindowStyle = ProcessWindowStyle.Normal;
start.CreateNoWindow = false;
start.RedirectStandardInput = true;
start.UseShellExecute = false;
// Run the external process & wait for it to finish
using (Process proc = Process.Start(start))
{
//doxygenProperties is just a dictionary
foreach (string key in doxygenProperties.Keys)
proc.StandardInput.WriteLine(key+" = "+doxygenProperties[key]);
proc.StandardInput.Close();
proc.WaitForExit();
// Retrieve the app's exit code
int exitCode = proc.ExitCode;
}

command redirection issue

here is my code
//Create process
System.Diagnostics.Process pProcess = new System.Diagnostics.Process();
//strCommand is path and file name of command to run
pProcess.StartInfo.FileName = "ffmpeg.exe";
//strCommandParameters are parameters to pass to program
pProcess.StartInfo.Arguments = "-i " + videoName;
pProcess.StartInfo.UseShellExecute = false;
//Set output of program to be written to process output stream
pProcess.StartInfo.RedirectStandardOutput = true;
//Start the process
pProcess.Start();
//Get program output
string strOutput = pProcess.StandardOutput.ReadToEnd();
//Wait for process to finish
pProcess.WaitForExit();
The command works, but strOutput string is empty, results are shown within the console. Am I missing something here?

It's possible the program is writing its output to StandardError instead of StandardOutput. Try using .RedirectStandardError = true and then .pProcess.StandardError.ReadToEnd() to capture that output.
If you need the possibility of capturing both standard error and standard out in (roughly) the proper interleave, you will likely need to use the async versions with callbacks on OutputDataReceived and ErrorDataReceived and using BeginOutput/ErrorReadLine.

Try to capture Std Error too as on any event of error, it will be used instead.
//Set output of program to be written to process output stream
pProcess.StartInfo.RedirectStandardError = true;
pProcess.StartInfo.RedirectStandardOutput = true;
//Start the process
pProcess.Start();
//Wait for process to finish
pProcess.WaitForExit();
//Get program output
string strError = pProcess.StandardError.ReadToEnd();
string strOutput = pProcess.StandardOutput.ReadToEnd();
I just wonder why you wait for exit WaitForExit after reading the output, it should be in reversed order as your app may dump more until it finally completes the ops

Control console application from Windows form application C#

I have 2 applications.
One of them is console application, the other is normal form application - both written in C#. I want to open (hidden from view) the console application form the windows form application and be able to send a command lines to the console application.
How can i do that?

You can start the background process
ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.FileName = "Myapplication.exe";
startInfo.WindowStyle = ProcessWindowStyle.Hidden;
Process process = new Process();
process.StartInfo = startInfo;
process.Start();
and after that use the Process.StandardOutput property
// This is the code for the base process
Process myProcess = new Process();
// Start a new instance of this program but specify the 'spawned' version.
ProcessStartInfo myProcessStartInfo = new ProcessStartInfo(args[0], "spawn");
myProcessStartInfo.UseShellExecute = false;
myProcessStartInfo.RedirectStandardOutput = true;
myProcess.StartInfo = myProcessStartInfo;
myProcess.Start();
StreamReader myStreamReader = myProcess.StandardOutput;
// Read the standard output of the spawned process.
string myString = myStreamReader.ReadLine();
Console.WriteLine(myString);
myProcess.WaitForExit();
myProcess.Close();
If you want to send commands to this process, just use Process.StandardInput Property
// Start the Sort.exe process with redirected input.
// Use the sort command to sort the input text.
Process myProcess = new Process();
myProcess.StartInfo.FileName = "Sort.exe";
myProcess.StartInfo.UseShellExecute = false;
myProcess.StartInfo.RedirectStandardInput = true;
myProcess.Start();
StreamWriter myStreamWriter = myProcess.StandardInput;
// Prompt the user for input text lines to sort.
// Write each line to the StandardInput stream of
// the sort command.
String inputText;
int numLines = 0;
do
{
Console.WriteLine("Enter a line of text (or press the Enter key to stop):");
inputText = Console.ReadLine();
if (inputText.Length > 0)
{
numLines ++;
myStreamWriter.WriteLine(inputText);
}
} while (inputText.Length != 0);

One of possible solutions can be IPC, in particularly
NamedPipes
That is already wrapped in .NET 4.0.
Regards.

To start the console application, use the System.Diagnostics.Process class.
To send commands to the console application you need something that is called Interprocess Communication. One way to do it is by using WCF. A simple tutorial can be found here.