将Powershell输出和错误重定向到控制台（实时）和变量 [英] Redirect powershell output and errors to console (in real-time) and to a variable

问题描述

我想按照以下规则重定向PowerShell中命令的输出：

I would like to redirect the output of a command in PowerShell, following these rules:

• 命令存储到变量

• The command is stored to a variable

输出必须实时写入控制台（即 ping结果），包括错误

Output must be written to the console in real-time (i.e. "ping" results), including errors

输出必须存储到一个变量中，包括错误（在此处不是实时的）

Output must be stored to a variable, including errors (real-time is not mandatory here)

这是我的测试，假设：

$command = "echo:"

测试错误重定向，并且：

to test errors redirection, and:

$command = "ping 127.0.0.1"

测试实时输出。

1. 输出是实时编写的，错误根本不会重定向

1. Output is written in real-time, errors are not redirected at all

Invoke-Expression $command 2>&1 | Tee-Object -Variable out_content

输出是实时编写的，错误仅被重定向

Output is written in real-time, errors are only redirected to the console

Invoke-Expression ($command 2>&1) | Tee-Object -Variable out_content
Invoke-Expression $command | Tee-Object -Variable out_content 2>&1

输出不是用实时间，错误被正确地重定向到两个

Output is not written in real-time, errors are correctly redirected to both

(Invoke-Expression $command) 2>&1 | Tee-Object -Variable out_content

是否可能才能使这些规则协同工作？

Is it possible to get those rules working together?

推荐答案

一些一般性建议：

• Invoke-Expression 通常应避免 ，因为它可能会带来安全风险并引入报价头痛；通常有更好，更安全的解决方案可用；除非没有其他解决方案，否则最好养成避免 Invoke-Expression 的习惯。

• Invoke-Expression should generally be avoided, because it can be a security risk and introduces quoting headaches; there are usually better and safer solutions available; best to form a habit of avoiding Invoke-Expression, unless there is no other solution.

从来没有理由使用 Invoke-Expression 来简单地执行带有参数的外部程序，例如 ping 127.0.0.1 ;只需直接调用 -支持这种直接调用是任何Shell的核心功能，PowerShell也不例外。

There is never a reason to use Invoke-Expression to simply execute an external program with arguments, such as ping 127.0.0.1; just invoke it directly - support for such direct invocations is a core feature of any shell, and PowerShell is no exception.

I 如果您确实需要将命令存储在变量中，或将其作为自变量 传递给以后，使用脚本块（ {...} ）；例如，使用 $ command = {ping 127.0.0.1} 代替 $ command ='ping 127.0.0.1' ，并使用& ，呼叫运算符，或。，点源运营商。

调用外部程序时，两个运算符表现出相同的行为。调用 PowerShell本机命令时，& 在子作用域中执行代码，而。（通常）在调用者的 current 范围内执行。

If you do need to store a command in a variable or pass it as an argument for later invocation, use script blocks ({ ... }); e.g., instead of $command = 'ping 127.0.0.1', use $command = { ping 127.0.0.1 }, and invoke that script block on demand with either &, the call operator, or ., the dot-sourcing operator.
When calling external programs, the two operators exhibit the same behavior; when calling PowerShell-native commands, & executes the code in a child scope, whereas . (typically) executes in the caller's current scope.

该 Invoke-Expression $ command 2>& 1 不能按预期工作 bug （自PowerShell Core 7.0.0-preview.3起），并已在此GitHub问题。

针对您的问题的解决方法：

PetSerAl 像以前一样无数次，在评论中提供了一种解决方案问题：

PetSerAl, as countless times before, has provided a solution in a comment on the question:

& { Invoke-Expression $command } 2>&1 | Tee-Object -Variable out_content

{...} 是一个脚本块文字，包含 Invoke-Expression 调用，并通过& 调用，即调用运算符，可将流重定向表达式 2>& 1 应用于&

{ ... } is a script-block literal that contains the Invoke-Expression call, and it is invoked with &, the call operator, which enables applying stream-redirection expression 2>&1 to the & call, which bypasses the bug.

^{如果 $ command 包含PowerShell-native您想直接在当前作用域中执行的命令（例如函数定义），请使用。而不是& 。}

^{If $command contained a PowerShell-native command that you wanted to execute directly in the current scope, such as a function definition, you'd use . instead of &.}

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