C＃程序调用，互动与标准输入和标准输出 [英] C# Process Call, Interact with Standard Input and Standard Output

问题描述

我有一个按钮，我点击了执行命令。该命令可能会弹出一些标准输入，我需要到输入响应，问题是这样的程序运行可能每天都在，所以我需要跨preT标准输出，并相应地重定向标准输入不同。

I have a button I click that executes a command. The command may prompt for some standard input and I need to respond to that input, the problem is the way the program runs may be different from day to day so I need to interpret the standard output and redirect standard input accordingly.

我有这样一段简单的code表示逐行读取标准输出线，当它看到密码的提示，它会发送标准输入，但该程序只是挂起，因为它从来没有看到提示为密码，但是当我运行该批处理文件中的密码提示是存在的。

I have this simple piece of code that reads the standard output line by line and when it sees a prompt for password, it'll send standard input, however the program just hangs since it never sees the prompt for the password, but when I run the batch file the password prompt is there.

下面是批处理文件我打电话来执行此测试：

Here is the batch file I am calling to execute this test:

@echo off
echo This is a test of a prompt
echo At the prompt, Enter a response
set /P p1=Enter the Password: 
echo you entered "%p1%"

下面是批处理文件的命令行中运行时的输出：

Here is the output of that batch file when run from the command line:

C:\Projects\SPP\MOSSTester\SPPTester\bin\Debug>test4.bat
This is a test of a prompt
At the prompt, Enter a response
Enter the Password: Test1
you entered "Test1"

下面是C＃代码片断我用来调用挂的批处理文件：

Here is the C# snippet I am using to call the batch file that is hanging:

    var proc = new Process();
    proc.StartInfo.FileName = "cmd.exe";
    proc.StartInfo.Arguments = "/c test4.bat";
    proc.StartInfo.RedirectStandardOutput = true;
    proc.StartInfo.RedirectStandardError = true;
    proc.StartInfo.RedirectStandardInput = true;
    proc.StartInfo.UseShellExecute = false;
    proc.StartInfo.CreateNoWindow = true;
    proc.Start();
    //read the standard output and look for prompt for password
    StreamReader sr = proc.StandardOutput;
    while (!sr.EndOfStream)
    {
        string line = sr.ReadLine();
        Debug.WriteLine(line);
        if (line.Contains("Password"))
        {
            Debug.WriteLine("Password Prompt Found, Entering Password");
            proc.StandardInput.WriteLine("thepassword");
        }
    }
    sr.Close();
    proc.WaitForExit();

下面是调试标准输出我看到，通知，我从来没有看到提示输入密码，这是为什么？它只是挂？<​​/ P>

Here is the debug standard output I see, notice that I never see the prompt for the password, why is this? it just hangs?

This is a test of a prompt
At the prompt, Enter a response

有没有一种方法可以让我看的提示标准输出，并作出相应的反应呢？

Is there a way I can watch the standard output for prompting and react to it accordingly?

推荐答案

您的主要问题是，你是通过流阅读器上使用工作 sr.ReadLine（）这是一个问题，因为提示输入密码，暂停直至用户输入新线（输入密码后点击进入）。

Your main problem is that you are working through the stream reader using sr.ReadLine() this is an issue because the prompt for a password halts until the user enters a new line (hits enter after typing the password).

所以，你需要读取流1个字符的时间。这个例子应该可以帮助您开始。

So you need to read the stream 1 character at a time. This example should help you get started.

while (!sr.EndOfStream)
{
    var inputChar = (char)sr.Read();
    input.Append(inputChar);
    if (StringBuilderEndsWith(input, Environment.NewLine))
    {
        var line = input.ToString();
        input = new StringBuilder();
        Debug.WriteLine(line);
    }
    else if (StringBuilderEndsWith(input, "Password:"))
    {
        Debug.WriteLine("Password Prompt Found, Entering Password");
        proc.StandardInput.WriteLine("thepassword");
        var line = input.ToString();
        input = new StringBuilder();
        Debug.WriteLine(line);
    }
}

private static bool StringBuilderEndsWith(StringBuilder haystack, string needle)
{
    var needleLength = needle.Length - 1;
    var haystackLength = haystack.Length - 1;
    for (int i = 0; i < needleLength; i++)
    {
        if (haystack[haystackLength - i] != needle[needleLength - i])
        {
            return false;
        }
    }
    return true;
}

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