Trying to get StandardOutput after running a console process - c#

I can run a console process using the following C# code. The goal is also to collect all the output from such process:
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo.Arguments = commandLine;
proc.StartInfo.FileName = "signtool.exe";
proc.StartInfo.RedirectStandardOutput = true;
proc.StartInfo.UseShellExecute = false;
proc.Start();
if (proc.WaitForExit(10000))
{
Debug.WriteLine(proc.StandardOutput.ReadToEnd());
}
What I receive is this:
"Done Adding Additional Store\r\n"
But when I do the same from a Windows command line I get this:
Done Adding Additional Store
SignTool Error: File not found: C:\SomeBadFile.exe
Why am I getting only the first line of output with my code?

Seeing as the line you are missing seems like an error message, should you not be looking at Process.StandardError Property
When a Process writes text to its standard error stream, that text is
normally displayed on the console. By redirecting the StandardError
stream, you can manipulate or suppress the error output of a process.
For example, you can filter the text, format it differently, or write
the output to both the console and a designated log file.

Have you tried redirecting and watching StandardError too? It seem likley that this is output to the error stream.

Related

Issue executing command line command in .NET c#

Attempting to run ntdsutil from a C# executable and encountering an error. In case anyone is wondering, this is for a automated auditing process as part of a managed service provider - not trying to create a trojan/malware.
The command is: ntdsutil "ac i ntds" "ifm" "create full c:\audit" q q
This is Windows server specific, am running on Windows 2016.
I am using System.Diagnostics.Process and have tried various combinations of properties but getting same result. The following is an example, there is a standard output redirect so can see results of execution:
Process process = new System.Diagnostics.Process();
ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo();
startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal;
startInfo.FileName = #"C:\Windows\System32\ntdsutil.exe";
startInfo.Arguments = "\"ac i ntds\" \"ifm\" \"create full c:\\audit\" q q";
//Set output of program to be written to process output stream
startInfo.RedirectStandardOutput = true;
startInfo.RedirectStandardError= true;
startInfo.UseShellExecute = false;
process.StartInfo = startInfo;
process.Start();
// Get program output
string strOutput = process.StandardOutput.ReadToEnd();
//Wait for process to finish
process.WaitForExit();
File.WriteAllText("out.txt", strOutput);
The output looks like this:
C:\Windows\System32\ntdsutil.exe: ifm
ifm: create full c:\audit
error 0x80042302(A Volume Shadow Copy Service component encountered an unexpected error. Check the Application event log for more information.)
ifm: q
C:\Windows\System32\ntdsutil.exe: q
Have checked event logs as mention (nothing obvious) and done various searches on error but nothing useful appears. Running the command on command line works fine.
It is running a Administrator level user. Is it possible related to app.manifest priveleges?
Any help is appreciated.

How to capture "Root Path" into a variable

I am trying to run logman.exe for a elevated CMD, for this below code I tried,
var proc = new Process
{
StartInfo = new ProcessStartInfo
{
FileName = #"C:\Windows\System32\cmd.exe",
Arguments = "cmd /k logman.exe PerfCounterCustom | findstr \"Root\"",
Verb = "runas",
UseShellExecute = true,
}
};
try
{
proc.Start();
while (!proc.StandardOutput.EndOfStream)
{
string line = proc.StandardOutput.ReadLine();
}
Console.WriteLine("Successfully elevated!");
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
And it's giving error output like,
System.InvalidOperationException: StandardOut has not been redirected or the process hasn't started yet.
at System.Diagnostics.Process.get_StandardOutput()
2 Questions,
when I am running application exe, it's showing 2 CMD window, the 1st one showing error and 2nd one showing result for argument "cmd /k logman.exe PerfCounterCustom | findstr \"Root\"" [Root Path]
how to disable showing both window?
Why I am getting this error?
To your 1st Question: In the ProcessStartInfo set WindowStyle to ProcessWindowStyle.Hidden
An alternative solution to read the output of the command is to write the output to a text file. Therefore you have to add >> "[Name or Path of file].txt" to the end of your command. Then just read the file from C# e.g. with File.ReadAllLines.
Two things to consider here:
If you do that often at Runtime and the command delivers huge amounts of text don't write it to an SSD.
Please check that the file is empty / not existing before, because Windows just appends the output to the end of the file. If you run that in multiple threads use a thread identifier in the file name.
You have to set RedirectStandardOutput of the ProcessStartInfo to true and you have to run proc.WaitForExit() before reading the output.
Please note that this solution causes incompatibilities with running the process as administrator via runas.

How can I open an external Java console application with arguments, capture output and execute commands on it?

I have a Java .jar application that is ran from a .bat file to have arguments passed to the Java application. The application opens a console (cmd.exe to be exact), writes things to it regularly and accepts some commands. I'm trying to create a kind-of wrapper around it in C# Winforms to ease it's use. How can I run the .jar with the same arguments as are in the .bat file, capture realtime output and write execute commands?
Yes, it is possible to do this using the System.Diagnostics.Process class and the ProcessStartInfo class from the .NET Framework. The Process class is used to control (start / stop) the desired process (application) and the ProcessStartInfo class is used to configure the process instance that will be started (arguments, redirect input and output, show / hide process window, and so on).
The code for starting a jar file looks like this:
var jarFile = "D:\\software\\java2html\\java2html.jar");
// location of the java.exe binary used to start the jar file
var javaExecutable = "c:\\Program Files (x86)\\Java\\jre7\\bin\\java.exe";
try
{
// command line for java.exe in order to start a jar file: java -jar jar_file
var arguments = String.Format(" -jar {0}", jarFile);
// create a process instance
var process = new Process();
// and instruct it to start java with the given parameters
var processStartInfo = new ProcessStartInfo(javaExecutable, arguments);
process.StartInfo = processStartInfo;
// start the process
process.Start();
}
catch (Exception exception)
{
Console.WriteLine(exception.Message);
}
The usual way to start a jar file is:
java -jar file.jar
To be sure, that the process will find the (in this case java) executable, it is a good practice to specify the fully qualified path to the process you want to start.
In order to redirect the standard output of the application you are starting, you need to set the ProcessStartInfo.RedirectStandardOutput property to true and then use the Process.StandardOutput property stream to fetch the output of the started application. The modified code for the application from the example above looks like this:
// command line for java.exe in order to start a jar file: java -jar jar_file
var arguments = String.Format(" -jar {0}", jarFile);
// indicate, that you want to capture the application output
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardOutput = true;
// create a process instance
var process = new Process();
// and instruct it to start java with the given parameters
var processStartInfo = new ProcessStartInfo(javaExecutable, arguments);
process.StartInfo = processStartInfo;
// start the process
process.Start();
// read the output from the started appplication
string output = process.StandardOutput.ReadToEnd();
process.WaitForExit();
If you want to control the input too, set the ProcessStartInfo.RedirectStandarInput property to true and then use the Process.StandardInput property stream to send input data to the started application.

How to redirect standard output when spawning a process

I've built a webservice for an internal server that I want to send a command to and have it launch a process. So I want to send a command to it like this:
http://machine:999/execute?path=c:\scripts\dostuff.exe&args=-test
The endpoint would then do something like this:
public ActionResult(string path, string args)
{
var proc = new System.Diagnostics.Process();
proc.StartInfo.FileName = path;
proc.StartInfo.Arguments = args;
proc.StartInfo.UseShellExecute = false;
proc.StartInfo.CreateNoWindow = true;
proc.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
proc.StartInfo.RedirectStandardOutput = true;
//Hook into all standard output here
//Block until process is returned - Async Controller action
return Content(output.ToString())
}
I want to be able to capture all the error messages and standard output generated by the executable. The executable could be anything like a console application or a powershell script. What's the best approach for doing something like this?
Use proc.StandardOutput.ReadToEnd() to read the redirected output stream to the end, and return that.
You may also want to set RedirectStandardError to True and do the same thing with proc.StandardError to get the error messages. You can spawn a background thread to synchronously read standard error alongside the reading of standard output in the main thread.

strange behaviour on another process via Process.Start(startInfo)

Our C# (V3.5) application needs to call another C++ executable which is from another company. we need to pass a raw data file name to it, it will process that raw data (about 7MB) file and generate 16 result files (about 124K for each).
The code to call that executable is this:
ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.CreateNoWindow = true;
startInfo.UseShellExecute = false;
startInfo.RedirectStandardError = true;
startInfo.RedirectStandardOutput = true;
startInfo.WindowStyle = ProcessWindowStyle.Hidden;
startInfo.FileName = exePath;
startInfo.Arguments = rawDataFileName;
try
{
Process correctionProcess = Process.Start(startInfo);
correctionProcess.WaitForExit();
}
catch(nvalidOperationException ex)
{
....
}
catch(...)
...
It works fine. Now we have new raw data. After replace the old raw data with the new raw data file. That executable process never return to us. It will hang forever. If we kill our C# application, those result files will be generated in the target directoy. It looks like the executable does create those result files but has issue to write to the disk and return to us until the process is terminated.
It is NOT like this with the old raw data file.
When we run the executable with the new raw data directly (no from our C# app call), it works fine. This means this executable has no problem with the new raw data.
My question 1: what's the possible causes for this behaviour?
Now I change our code with startInfo.UseShellExecute = true; and add startInfo.WorkingDirectory= ..., and disabled
//startInfo.RedirectStandardError = true;
//startInfo.RedirectStandardOutput = true;
Then it works.
My question 2: why use Windows Shell solve this issue?
My question 3: why it works before without using Shell?
My question 4: when we should use Shell and When shouldn't?
thanks,
Several possibilities:
You are redirecting output and error but not reading it. The process will stall when its stdout or stderr buffer fills up to capacity.
The program might be displaying an error message and waiting for a keypress. You are not redirecting input nor check stderr, that keypress will never come.
Some programs, xcopy.exe is a very good example, require stdin to be redirected when you redirect stdout. Although the failure mode for xcopy.exe is an immediate exit without any diagnostic.
Seeing it fixed when you kill your C# program makes the first bullet the likeliest reason.
I know this, it is a very common problem. I has to do with the output, which must be handled asynchronously. You just can't WaitForExit when output exceeds certain amount of data.
You need to add
myStdErr= correctionProcess.StandardError.ReadToEnd();
Only once usually works, if you want to overkill this works ("P" being my Process)
while (!P.HasExited)
stdErr+= P.StandardError.ReadToEnd();
If you don't need the stdout/stderr, just turn the Redirect* properties to false.

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