我如何从c#执行命令行程序,并获得STD OUT结果?具体来说,我想对两个以编程方式选择的文件执行DIFF,并将结果写入一个文本框。


当前回答

// usage
const string ToolFileName = "example.exe";
string output = RunExternalExe(ToolFileName);

public string RunExternalExe(string filename, string arguments = null)
{
    var process = new Process();

    process.StartInfo.FileName = filename;
    if (!string.IsNullOrEmpty(arguments))
    {
        process.StartInfo.Arguments = arguments;
    }

    process.StartInfo.CreateNoWindow = true;
    process.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
    process.StartInfo.UseShellExecute = false;

    process.StartInfo.RedirectStandardError = true;
    process.StartInfo.RedirectStandardOutput = true;
    var stdOutput = new StringBuilder();
    process.OutputDataReceived += (sender, args) => stdOutput.AppendLine(args.Data); // Use AppendLine rather than Append since args.Data is one line of output, not including the newline character.

    string stdError = null;
    try
    {
        process.Start();
        process.BeginOutputReadLine();
        stdError = process.StandardError.ReadToEnd();
        process.WaitForExit();
    }
    catch (Exception e)
    {
        throw new Exception("OS error while executing " + Format(filename, arguments)+ ": " + e.Message, e);
    }

    if (process.ExitCode == 0)
    {
        return stdOutput.ToString();
    }
    else
    {
        var message = new StringBuilder();

        if (!string.IsNullOrEmpty(stdError))
        {
            message.AppendLine(stdError);
        }

        if (stdOutput.Length != 0)
        {
            message.AppendLine("Std output:");
            message.AppendLine(stdOutput.ToString());
        }

        throw new Exception(Format(filename, arguments) + " finished with exit code = " + process.ExitCode + ": " + message);
    }
}

private string Format(string filename, string arguments)
{
    return "'" + filename + 
        ((string.IsNullOrEmpty(arguments)) ? string.Empty : " " + arguments) +
        "'";
}

其他回答

这可能不是最好/最简单的方法,但可能是一种选择:

当从代码执行时,添加“> output.txt”,然后读入output.txt文件。

您可以使用Process类启动任何命令行程序,并使用您创建的流阅读器(基于字符串或内存位置)设置Process实例的StandardOutput属性。流程完成后,您就可以在流上执行所需的任何diff。

如果你还需要在cmd.exe中执行一些命令,你可以这样做:

// 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 = "cmd.exe";
p.StartInfo.Arguments = "/C vol";
p.Start();
// Read the output stream first and then wait.
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine(output);

这只返回命令本身的输出:

你也可以用StandardInput代替StartInfo。参数:

// Start the child process.
Process p = new Process();
// Redirect the output stream of the child process.
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardInput = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.FileName = "cmd.exe";
p.Start();
// Read the output stream first and then wait.
p.StandardInput.WriteLine("vol");
p.StandardInput.WriteLine("exit");
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();
Console.WriteLine(output);

结果如下所示:

只是为了好玩,这里是我完整的获得PYTHON输出的解决方案-在单击按钮下-带有错误报告。只需添加一个名为“butPython”的按钮和一个名为“llHello”的标签…

    private void butPython(object sender, EventArgs e)
    {
        llHello.Text = "Calling Python...";
        this.Refresh();
        Tuple<String,String> python = GoPython(@"C:\Users\BLAH\Desktop\Code\Python\BLAH.py");
        llHello.Text = python.Item1; // Show result.
        if (python.Item2.Length > 0) MessageBox.Show("Sorry, there was an error:" + Environment.NewLine + python.Item2);
    }

    public Tuple<String,String> GoPython(string pythonFile, string moreArgs = "")
    {
        ProcessStartInfo PSI = new ProcessStartInfo();
        PSI.FileName = "py.exe";
        PSI.Arguments = string.Format("\"{0}\" {1}", pythonFile, moreArgs);
        PSI.CreateNoWindow = true;
        PSI.UseShellExecute = false;
        PSI.RedirectStandardError = true;
        PSI.RedirectStandardOutput = true;
        using (Process process = Process.Start(PSI))
            using (StreamReader reader = process.StandardOutput)
            {
                string stderr = process.StandardError.ReadToEnd(); // Error(s)!!
                string result = reader.ReadToEnd(); // What we want.
                return new Tuple<String,String> (result,stderr); 
            }
    }

The accepted answer on this page has a weakness that is troublesome in rare situations. There are two file handles which programs write to by convention, stdout, and stderr. If you just read a single file handle such as the answer from Ray, and the program you are starting writes enough output to stderr, it will fill up the output stderr buffer and block. Then your two processes are deadlocked. The buffer size may be 4K. This is extremely rare on short-lived programs, but if you have a long running program which repeatedly outputs to stderr, it will happen eventually. This is tricky to debug and track down.

有一些很好的方法来处理这个问题。

One way is to execute cmd.exe instead of your program and use the /c argument to cmd.exe to invoke your program along with the "2>&1" argument to cmd.exe to tell it to merge stdout and stderr. var p = new Process(); p.StartInfo.FileName = "cmd.exe"; p.StartInfo.Arguments = "/c mycmd.exe 2>&1"; Another way is to use a programming model which reads both handles at the same time. var p = new Process(); p.StartInfo.FileName = "cmd.exe"; p.StartInfo.Arguments = @"/c dir \windows"; p.StartInfo.CreateNoWindow = true; p.StartInfo.RedirectStandardError = true; p.StartInfo.RedirectStandardOutput = true; p.StartInfo.RedirectStandardInput = false; p.OutputDataReceived += (a, b) => Console.WriteLine(b.Data); p.ErrorDataReceived += (a, b) => Console.WriteLine(b.Data); p.Start(); p.BeginErrorReadLine(); p.BeginOutputReadLine(); p.WaitForExit();