定义一个新的句柄（到STDOUT类似） [英] Define a new handle (Similar to STDOUT)

问题描述

我看着批量重定向手柄，当我注意到了这一点：

下面是链接

有提到，拉手3-9未定义，并且可以通过程序来限定。现在，我读过有关在C＃中这样做，但我想知道这在cmd中/批是可能的 - 如果它是什么是它的局限性/使用

如果这是不可能在cmd中我将如何去使用这一点，可以把它是允许输出数据到屏幕soloution，并在同一时间（这已不能是一个问题它重定向到文件同时legitametly完成）。

谢谢，蒙娜丽莎。

解决方案

一个批处理文件限制为只管理两个文件：STDIN输入（SET / P）操作，STDOUT输出（ECHO等）的操作;然而，我们可以有权访问多个输入和输出文件在一个批处理文件。怎么做？在一个相对简单的方法：只需将其他文件未使用手柄（3-9），并输入用此时，相应的手柄（SET / P＆LT;＆安培;＃）或输出（ECHO>＆安培;＃）命令

下面的批处理文件合并的3输入文件的行到一个输出文件具有较大的行：

 关闭@echo
SETLOCAL EnableDelayedExpansion
3'; input2.txt 4℃; input3.txt（
FOR / Fdelims =%%一中（input1.txt）做（
   集线=
   REM阅读来自input2.txt（和写入线从INPUT1到output.txt）：
   集/普线= %% A＆LT;及3
   REM阅读来自input3.txt（和写入线从输入2到output.txt）：
   集/ p =行！行！ ＆LT;及4
   从输入3 REM写一行到output.txt：
   回声（！行！
）
）＆GT; output.txt的
 

同样的方法可以用于产生多个输出文件。

请参阅：几个文件访问通过标准把手

和更技术性的解释这里

I was looking at redirecting handles in batch, when I noticed this:

Here is the link

It mentions that Handle 3-9 are undefined and can be defined by a program. Now I've read about doing this in C#, but I wondered if this was possible in cmd/batch - and if it is what are its limitations/use.

If it is not possible in cmd how would I go about using this, and could it be a soloution to outputing data to the screen and redirecting it to a file at the same time (a problem which has not been able to be done legitametly at the same time).

Thanks, Mona.

解决方案

A Batch file is limited to manage just two files: STDIN for input (SET /P) operations, and STDOUT for output (ECHO, etc.) operations; however, we could have access to more than one input and output files in a Batch file. How to do that? In a relatively easy way: just connect the additional files to unused handles (3-9) and use the appropiate handle in the input (SET /P <&#) or output (ECHO >&#) commands.

The Batch file below merge the lines of 3 input files into one output file with larger lines:

@echo off
setlocal EnableDelayedExpansion
3<input2.txt 4<input3.txt (
for /F "delims=" %%a in (input1.txt) do (
   set line=
   rem Read from input2.txt (and write line from input1 to output.txt):
   set /P line=%%a <&3
   rem Read from input3.txt (and write line from input2 to output.txt):
   set /P line=!line! <&4
   rem Write line from input3 to output.txt:
   echo(!line!
)
) >output.txt

The same method may be used to generate several output files.

See: Access to SEVERAL files via Standard Handles

And a more technical explanation here

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