如何检测Console.In（stdin）是否已重定向？ [英] How to detect if Console.In (stdin) has been redirected?

问题描述

我想编写一个具有不同行为的控制台应用程序，取决于输入是来自键盘还是来自一个文件。

是否可能？

解决方案

你可以通过p /调用Windows FileType功能。这是一个帮助类：

 使用System; 
 using System.Runtime.InteropServices; 
 
 public static class ConsoleEx {
 public static bool IsOutputRedirected {
 get {return FileType.Char！= GetFileType（GetStdHandle（StdHandle.Stdout））; } 
} 
 public static bool IsInputRedirected {
 get {return FileType.Char！= GetFileType（GetStdHandle（StdHandle.Stdin））; } 
} 
 public static bool IsErrorRedirected {
 get {return FileType.Char！= GetFileType（GetStdHandle（StdHandle.Stderr））; } 
} 
 
 // P / Invoke：
 private enum FileType {Unknown，Disk，Char，Pipe}; 
 private enum StdHandle {Stdin = -10，Stdout = -11，Stderr = -12}; 
 [DllImport（kernel32.dll）] 
 private static extern FileType GetFileType（IntPtr hdl）; 
 [DllImport（kernel32.dll）] 
 private static extern IntPtr GetStdHandle（StdHandle std）; 
} 
  

用法：

  bool inputRedirected = ConsoleEx.IsInputRedirected; 
  
 
 
 
 
 
 
 UPDATE：这些方法已添加到Console类在.NET 4.5。没有归属我可以添加:(只需使用相应的方法，而不是这个帮助类。
 
 
 
  https://msdn.microsoft.com/en-us/library/system.console.isoutputredirected.aspx  
  https://msdn.microsoft.com/en-us/ library / system.console.isinputredirected.aspx  
  https://msdn.microsoft.com/en-us/library/system.console.iserrorredirected.aspx  
 
I want to write a console application that have a different behavior depending if the input is coming from keyboard or from, say, a file.

Is it possible? What's the most elegant way to do it in C#?
解决方案
You can find out by p/invoking the Windows FileType() API function.  Here's a helper class:
using System;
using System.Runtime.InteropServices;

public static class ConsoleEx {
    public static bool IsOutputRedirected {
        get { return FileType.Char != GetFileType(GetStdHandle(StdHandle.Stdout)); }
    }
    public static bool IsInputRedirected {
        get { return FileType.Char != GetFileType(GetStdHandle(StdHandle.Stdin)); }
    }
    public static bool IsErrorRedirected {
        get { return FileType.Char != GetFileType(GetStdHandle(StdHandle.Stderr)); }
    }

    // P/Invoke:
    private enum FileType { Unknown, Disk, Char, Pipe };
    private enum StdHandle { Stdin = -10, Stdout = -11, Stderr = -12 };
    [DllImport("kernel32.dll")]
    private static extern FileType GetFileType(IntPtr hdl);
    [DllImport("kernel32.dll")]
    private static extern IntPtr GetStdHandle(StdHandle std);
}
Usage:
bool inputRedirected = ConsoleEx.IsInputRedirected;




UPDATE: these methods were added to the Console class in .NET 4.5.  Without attribution I might add :(  Simply use the corresponding method instead of this helper class.

https://msdn.microsoft.com/en-us/library/system.console.isoutputredirected.aspx
https://msdn.microsoft.com/en-us/library/system.console.isinputredirected.aspx
https://msdn.microsoft.com/en-us/library/system.console.iserrorredirected.aspx

                        
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