在 Windows 中，2<&1 和 2>&1 之间有什么区别？
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In Windows, what's the difference between 2<&1 and 2>&1?
提问by theglauber
The examples and explanations in this page are leaving me confused:
此页面中的示例和解释让我感到困惑：
Is there any practical difference between using 2<&1 and 2>&1? The second form (2>&1) is familiar to me, from working with the Unix shell.
使用 2<&1 和 2>&1 之间有什么实际区别吗？第二种形式 (2>&1) 对我来说很熟悉，因为它是在 Unix shell 中工作的。
The page linked above has:
上面链接的页面有：
To find File.txt, and then redirect handle 1 (that is, STDOUT) and handle 2 (that is, STDERR) to the Search.txt, type:
findfile file.txt>search.txt 2<&1
要查找 File.txt，然后将句柄 1（即 STDOUT）和句柄 2（即 STDERR）重定向到 Search.txt，请键入：
findfile file.txt>search.txt 2<&1
and also
并且
To redirect all of the output, including handle 2 (that is, STDERR), from the ipconfig command to handle 1 (that is, STDOUT), and then redirect the ouput to Output.log, type:
ipconfig.exe>>output.log 2>&1
要将所有输出（包括句柄 2（即 STDERR））从 ipconfig 命令重定向到句柄 1（即 STDOUT），然后将输出重定向到 Output.log，请键入：
ipconfig.exe>>output。日志 2>&1
In the end, is there any difference in the results?
最后，结果有什么不同吗？
采纳答案by Andy Morris
Some examples should show what happens:
一些示例应该显示会发生什么：
c:\YourDir> cd FolderNotHere > nul
The system cannot find the path specified.
You get the error stream
你得到错误流
c:\YourDir>cd FolderNotHere > nul 2>&1
You get nothing, the error stream goes to the std output stream which goes to null.
你什么也得不到，错误流进入到空的 std 输出流。
c:\YourDir>cd > nul
You get nothing, the output stream goes to null.
你什么也得不到，输出流变为空。
c:\YourDir>cd > nul 1>&2
c:\YourDir
You get the std outout which has been sent to the error stream so it doesn't get redirected.
您获得已发送到错误流的 std 输出，因此它不会被重定向。
c:\YourDir>cd > nul 1<&2
This seams to do the same as 1>&2
这接缝与 1>&2 相同
