做一个PowerShell的函数/任务在后台运行 [英] Make a Powershell function/task run in the background

问题描述

我有一个功能，可以让我写文件的文件路径到一个文本文件，这取决于您的输入。这听起来令人困惑，但我不知道一个更好的方式把它，所以这里的功能：

I have a function that lets me write the file-path of files to a text file, depending on your input. That sounds confusing, but I don't know of a better way to put it, so here's the function:

Function writeAllPaths([string]$fromFolder,[string]$filter,[string]$printfile) {
    Get-ChildItem -Path $fromFolder -Recurse $filter | Select-Object -Property FullName > $printfile
}

第一个参数是文件夹，你开始从搜索。结果
第二个参数，过滤器。 * .ZIP例如，将列出所有zip文件。
第三个参数，你必须提供该文本文件将结束。

First argument being the folder you start your search from.
Second argument, the filter. *.zip for instance, will list all zip files. Third argument, you have to provide where the text file will end up.

使用范例： writeAllPaths C：\\ * .zip文件C：\\ allZips.txt

问题是，当我这样做，直到把它完成PowerShell不会接受命令。这是不是很高效。有没有办法启动的时候有这个在后台运行。而当它完成preferably，给一点消息。我可以开口，在该过程的中间被创建的任何文件...

The thing is, when I do this, Powershell won't accept commands until it's done. Which isn't very productive. Is there a way to have this run in the background when started. And preferably, give a little message when it's done. I could be opening any file that's being created in the middle of the process...

此外，我在Windows 7上，所以我猜，我有PowerShell 2.0中

Also, I'm on Windows 7, so I'm guessing that I have Powershell 2.0

是啊，我不知道这件事：P

Yeah, I'm not sure about it :p

编辑：

我用的启动工作，所建议的，如下：

I used Start-Job, as suggested, as follows:

Function writeAllPaths([string]$fromFolder,[string]$filter,[string]$printfile) {
  Start-Job -ScriptBlock {Get-ChildItem -Path $fromFolder -Recurse $filter | Select-Object -Property FullName > $printfile}
}

但是，不创建的文件。旧的功能确实创建了一个文件。结果

However, the file isn't created. The old function does create a file.

EDIT2：这将是preferable有这项功能在我的PowerShell配置文件中。这样一来，我可以执行它，每当我想要的，而不必在具体的PS1文件每次我开机Powershell的时间来加载。

it would be preferable to have this function in my Powershell profile. This way, I can execute it whenever I want, instead of having to load in the specific ps1 file every time I boot Powershell.

在PowerShell配置更多信息可以在这里找到
您可以通过键入召唤自己的个人资料：记事本$简介

More info on the Powershell profile can be found here You can summon your own profile by typing: notepad $profile

推荐答案

在新的范围内创建的后台作业，为你WriteAllPaths函数中定义您的参数没有定义。试试这个，你会看到他们是不是：

In the new scope you create for the background job, your parameters defined for you WriteAllPaths function are not defined. Try this and you'll see they aren't:

Function writeAllPaths([string]$fromFolder,[string]$filter,[string]$printfile) 
{    
    Start-Job { "$fromFolder, $filter, $printFile" }
}

$job = WriteAllPaths .\Downloads *.zip zips.txt
Wait-Job $job
Receive-Job $job

, ,

试试这个：

Function writeAllPaths([string]$fromFolder, [string]$filter, [string]$printfile) 
{    
    Start-Job {param($fromFolder,$filter,$printfile) 
               "$fromFolder, $filter, $printfile" } `
               -ArgumentList $fromFolder,$filter,$printfile
}

$job = WriteAllPaths .\Downloads *.zip z.txt
Wait-Job $job
Receive-Job $job

.\Downloads, *.zip, z.txt

现在你看到你的输出，因为我们通过通过-ArgumentList的脚本块传递的参数。我会建议是，可以选择使用后台作业功能。只要坚持这个函数定义您的个人资料和你设置：

Now you see your output because we passed the parameters through to the scriptblock via -ArgumentList. What I would recommend is a function that can optionally use a background job. Just stick this function definition in your profile and you're set:

function WriteAllPaths([string]$FromFolder, [string]$Filter, 
                       [string]$Printfile, [switch]$AsJob) 
{
    if (![IO.Path]::IsPathRooted($FromFolder)) {
        $FromFolder = Join-Path $Pwd $FromFolder
    }
    if (![IO.Path]::IsPathRooted($PrintFile)) {
        $PrintFile = Join-Path $Pwd $PrintFile
    }

    $sb = {
        param($FromFolder, $Filter, $Printfile)
        Get-ChildItem $FromFolder -r $filter | Select FullName > $PrintFile
    }

    if ($AsJob) {
        Start-Job $sb -ArgumentList $FromFolder,$Filter,$PrintFile
    }
    else {
        & $sb $FromFolder $Filter $PrintFile        
    }
}

测试功能（同步），像​​这样：

Test the function (synchronously) like so:

$job = WriteAllPaths Downloads *.zip z.txt -AsJob
Wait-Job $job
Receive-Job $job

请注意，我测试如果路径是根，如果没有我prepending当前目录。我这样做是因为后台作业的首发DIR并不总是一样的，你从执行的启动工作在哪里。

Note that I'm testing if the path is root and if not I'm prepending the current dir. I do this because the background job's starting dir is not always the same as where you executed Start-Job from.

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