在屏幕和变量中调用表达式输出 [英] Invoke-expression output on Screen and in a variable

问题描述

我正在尝试将 Invoke-expression 的输出存储到一个变量以及屏幕上.我有 PS 日志记录，它自动将所有内容作为 Write-Host 记录在文件中.现在我正在使用 Invoke-Expression 似乎要么在屏幕上打印输出，要么打印到变量，我需要两者

I am trying to store output from Invoke-expression into a variable as well as on screen. I have PS logging which automatically log everything as Write-Host in a file. Now I am using Invoke-Expression which seems to either print the output on Screen or to a variable, I need both

我所尝试的只是:

$var = "C:\ER\work\Canny.exe -Init ER\ER2 Get-ip"

$val = Invoke-Expression $var

这不会在屏幕上打印任何内容，因此我无法知道运行时是否有任何问题.我后来做了一个 $val 的 Write-Host 记录它，但有时知道发生了什么为时已晚如果我使用:

This doesn't print anything on Screen so I am unable to know if there are any issues while running. I later do a Write-Host of $val which logs it but its sometimes too late to know what happened If I use:

Invoke-Expression $var

没有记录任何内容(显然)，但有控制台输出，如果我想在一段时间后查看日志中发生了什么，我无法进行调查.我也试过:

Nothing is logged (obviously), but there is console output and if I want to see after sometime for logs what happened, I have no way of Investigating. I have also tried :

Invoke-Expression $var -OutVariable out 

或

Invoke-Expression $var -OutVariable $out 

这在这里没有用.我还创建了一个脚本块并尝试使用

This is of no use here. I have also created a script block and tried with

Invoke-Command 

但同样没用，我只需要它在屏幕和变量上打印输出.

but again of no use I just need it to print the output on Screen as well as to a variable.

推荐答案

Invoke-Expression -Command $var -OutVariable out 应该可以工作(变量 + 控制台输出)，但是发生了一些奇怪的事情.它适用于 ISE，但在普通的 PowerShell 控制台中，我得到一个空的 ArrayList.如果您将其通过管道传递给另一个命令，例如 Out-String，它会起作用(但这将返回单个多行字符串).

Invoke-Expression -Command $var -OutVariable out should work (variable + console output), but there's something weird going on. It works in ISE, but in a normal PowerShell console I get an empty ArrayList. If you pipe it to another command like Out-String it works (but this would return a single multi-line string).

Invoke-Expression -Command $var | Out-String -OutVariable out

要么是我忘记了什么，要么是 Invoke-Expression 的错误.

Either I'm forgetting something or it might be a bug with Invoke-Expression.

一种解决方法是使用 Tee-Object 与 -OutVariable 的行为相同.

A workaround would be to use Tee-Object which behaves the same as -OutVariable.

Tee-Object cmdlet 重定向输出，即发送输出两个方向的命令(如字母T").它存储了在文件或变量中输出，并将其发送到管道中.如果Tee-Object 是管道中的最后一个命令，命令输出为显示在提示处.

The Tee-Object cmdlet redirects output, that is, it sends the output of a command in two directions (like the letter "T"). It stores the output in a file or variable and also sends it down the pipeline. If Tee-Object is the last command in the pipeline, the command output is displayed at the prompt.

示例:

Invoke-Expression $var -OutVariable | Tee-Object -Variable out 

或(到文件):

Invoke-Expression $var -OutVariable | Tee-Object -FilePath c:\text.txt

注意它会覆盖$out中的内容.

Be aware that it overwrites the content in $out.

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