Why is Process.StandardInput.WriteLine not supplying input to my process?

Question

this is my first question here so I\'ll be as detailed as I can. I am currently working on a C# program (We\'ll call it TestProgram) that tests a different program written i

Answer 1

I think the problem is in your C program, not in your C# program. When you produce your output, you do not put \n at the end. Hence StandardOutput.ReadLine() will wait forever, because there is no end-of-line marker in the stream.

Since the output of your C program is used to synchronize the steps of your co-operating programs, it is also a very good idea to flush it to the output before waiting for the next portion of input:

printf("%s\n", result);
fflush(stdout);

Answer 2

Your C# code seems to be just fine, I tried it with another C# program:

static void Main(string[] args)
{
    String line = Console.ReadLine();
    Console.WriteLine("I received " + line);
}

And the following code outputs "I received Hello world!". So the problem must be in your C code. As dasblinkenlight already mentioned, new line symbols might be missing.

static void Main(string[] args)
{
    Process cmd = new Process();

    ProcessStartInfo info = new ProcessStartInfo(@"AnotherApp.exe", "");
    info.WorkingDirectory = @"path\to\folder";
    info.RedirectStandardInput = true;
    info.RedirectStandardOutput = true;
    info.RedirectStandardError = true;
    info.UseShellExecute = false;
    cmd.StartInfo = info;
    cmd.Start();

    cmd.StandardInput.WriteLine("Hello world!");

    String output = cmd.StandardOutput.ReadLine();
    Console.WriteLine(output);

    Console.ReadKey();
}