How to redirect process output to System.String

Question

I am calling Java process from .NET application and I need to redirect console output to System.String to do some later parsing. Please advice. I would appreciate short code example.

public bool RunJava(string fileName)
{
    try
    {
        ProcessStartInfo psi = new ProcessStartInfo();
        psi.CreateNoWindow = true;
        psi.UseShellExecute = false;
        psi.EnvironmentVariables.Add("VARIABLE1", "1");
        psi.FileName = "JAVA.exe";
        psi.Arguments = "-Xmx256m jar.name";

        Process.Start(psi);
        return true;
    }
    catch (Exception ex)
    {
        return false;
    }
}

score 15 · Accepted Answer · answered Sep 30 '10 at 10:48

A better way will be to create a Process instance and capture the output using a stream like this:

Process cmd = new Process();
cmd.StartInfo.FileName = "JAVA.exe";
cmd.StartInfo.Arguments = "-Xmx256m jar.name";
cmd.StartInfo.UseShellExecute = false;
cmd.StartInfo.CreateNoWindow = true;
cmd.StartInfo.RedirectStandardOutput = true;
cmd.StartInfo.EnvironmentVariables.Add("VARIABLE1", "1");
cmd.Start();

StreamReader sr = cmd.StandardOutput;
string output = sr.ReadToEnd();
cmd.WaitForExit();

score 7 · Answer 2 · answered Sep 30 '10 at 10:39

7

You need to set RedirectStandardOutput to true, and then the easiest way of getting the results is to use the event-driven mechanism:

Process p = Process.Start(psi);
p.BeginOutputReadLine(LineHandler);
p.EnableRaisingEvents = true;

where LineHandler is an appropriate method to collect each line of output, e.g. into a StringWriter.

answered Sep 30 '10 at 10:39

Jon Skeet

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Thanks Jon. Will give it a try. Will update my question as soon as new issues come up. – Captain Comic Sep 30 '10 at 10:42

score 2 · Answer 3 · edited Apr 28 '13 at 19:14

2

Set
ProcessStartInfo.RedirectStandardOutput
and
.RedirectStandardError.
Then you can read the StandardOutput and StandardError-streams on the Process-object that is returned from Process.Start.

MSDN have a nice and simple sample for you.

edited Apr 28 '13 at 19:14

Mustafa Ekici

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answered Sep 30 '10 at 10:42

Rune

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How to redirect process output to System.String

3 Answers3

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