一个命令的输出设置为变量（含管道） [英] Set output of a command as a variable (with pipes)

问题描述

你能使用的管道命令的输出重定向到一个变量？

Can you redirect the output of a command to a variable with pipes?

我没有尝试过很多，因为我一直没能想到的任何尝试，但我已经试过的一种方法（有两个变异）...

I haven't tried much as I haven't been able to think of anything to try, but I have tried one method (with two variations)...

例如：

echo Hello|set text=

没有工作，也没有：

Didn't work, neither did:

echo Hello | set text=

我知道你可以用的命令做到这一点很容易，但我认为它看起来漂亮与管道。

I know you can do it fairly easily with the FOR command, but I think it would look "nicer" with a pipe.

如果你想知道，我没有，我问这个以外我很好奇，我无法找到答案的具体原因。

And if you're wondering, I don't have a specific reason I'm asking this other than I'm curious and I can't find the answer.

推荐答案

您的方法不能，原因有二。

Your way can't work for two reasons.

您需要使用设置/ p =文本用于设置变量的用户输入的。结果
另一个问题是在管道上。结果，
一个管道启动两个异步cmd.exe的实例，并在完成作业后两种情况下是关闭的。

You need to use set /p text= for setting the variable with user input.
The other problem is the pipe.
A pipe starts two asynchronous cmd.exe instances and after finishing the job both instances are closed.

这就是为什么的原因，似乎这两个变量没有设置，但一个小的例子表明，它们设置但结果是后来丢失了。

That's the cause why it seems that the variables are not set, but a small example shows that they are set but the result is lost later.

set myVar=origin
echo Hello | (set /p myVar= & set myVar)
set myVar

输出

Hello
origin

替代：您可以用FOR循环获取值变量或者也临时文件

Alternatives: You can use the FOR loop to get values into variables or also temp files.

for /f "delims=" %%A in ('echo hello') do set "var=%%A"
echo %var%

或

>output.tmp echo Hello
>>output.tmp echo world

<output.tmp (
  set /p line1=
  set /p line2=
)
echo %line1%
echo %line2%

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