sample.cs

public static int ExecuteProcess(
    string fileName,
    string arguments,
    int timeout,
    out string standardOutput,
    out string standardError)
{
    int exitCode;
 
    var standardOutputBuilder = new StringBuilder();
    var standardErrorBuilder = new StringBuilder();
 
    using (var process = new Process())
    {
        process.StartInfo.UseShellExecute = false;
        process.StartInfo.CreateNoWindow = true;
        process.StartInfo.RedirectStandardError = true;
        process.StartInfo.RedirectStandardOutput = true;
        process.StartInfo.FileName = fileName;
        process.StartInfo.Arguments = arguments;
 
        process.OutputDataReceived += (sender, args) =>
        {
            if (args.Data != null)
            {
                standardOutputBuilder.AppendLine(args.Data);
            }
        };
        process.ErrorDataReceived += (sender, args) =>
        {
            if (args.Data != null)
            {
                standardErrorBuilder.AppendLine(args.Data);
            }
        };
 
        process.Start();
 
        // This is our place of interest
 
        process.BeginOutputReadLine();
        process.BeginErrorReadLine();
 
        if (process.WaitForExit(timeout))
        {
            process.WaitForExit(); // <-- this makes sure that streams flushed
            exitCode = process.ExitCode;
        }
        else
        {
            process.Kill();
 
            throw new TimeoutException("Process wait timeout expired");
        }
    }
 
    standardOutput = standardOutputBuilder.ToString();
    standardError = standardErrorBuilder.ToString();
 
    return exitCode;
}