.net – PowerShell中的echo和Write-Host有什么区别？

我对PowerShell中回声和写入主机之间的区别感到困惑。我有两个文件，POC.ps1& validatePath.ps1。这些文件在我的本地机器上，我使用Invoke-Command在远程机器上运行它们。我正在使用PowerShell v3.0。

要执行这两个脚本，我使用命令：

.\POC.ps1 -filename C:\Users  -user Blaine

以下是两个文件：

POC.ps1：

param($filename,$user)

echo $filename
echo "This"
echo $user

$responSEObject = Invoke-Command testcomputer -FilePath .\validatePath.ps1  -ArgumentList($filename,$user) -AsJob

while($responSEObject.State -ne "Completed")
{

}

$result = Receive-Job -Id $responSEObject.Id -Keep
echo $result

这里是什么东西变得奇怪？

validatePath.ps1：

Param([string] $filename,[string] $user)

function ValidatePath( $filename,$user,$fileType = "container" )
{
    Write-Host "This is the file name: $filename"
    Write-Host "This is user: $user"  <--- Notice I'm using Write-Host here
    $fileExist = $null
    if( -not (test-path $filename -PathType $fileType) )
    {
        throw "$user,the path $filename does not exist!"

    }
    else
    {
         Write-Host "This is the second part"
         echo $filename found!
    }
    Write-Host "This is the third part"
    return $fileExist
}


try
{

    ValidatePath($filename,$user)
}
catch
{
    $e = $_.Exception
    echo $e
}

当我运行上面的脚本，这是输出：

C:\Users
This
Blaine
This is the file name: C:\Users Blaine
This is user:  <--- Notice where this line is?
This is the second part
This is the third part
C:\Users
Blaine
found!

但是如果我将validatePath.ps1更改为：

Param([string] $filename,$fileType = "container" )
{
    Write-Host "This is the file name: $filename"
    echo "This is user: $user" <---notice I'm using Echo here
    $fileExist = $null
    if( -not (test-path $filename -PathType $fileType) )
    {
        throw "$user,the path $filename does not exist!"

    }
    else
    {
         Write-Host "This is the second part"
         echo $filename found!
    }
     Write-Host "This is the third part"
    return $fileExist
}


try
{

    ValidatePath($filename,$user)
}
catch
{
    $e = $_.Exception
    echo $e
}

这是输出：

C:\Users
This
Blaine
This is the file name: C:\Users Blaine
This is the second part
This is the third part
This is user: <---- Notice where this line is Now?
C:\Users
Blaine
found!

你会注意到，这行“这是用户：”在不同的地方。为什么是这样？为什么回声工作与写入主机不同？

更新：

更奇怪的是，如果我像这样重新运行脚本：

POC.ps1：

param($filename,$user)

echo $filename
echo "This"
echo $user

$responSEObject = Invoke-Command CAPTESTPK01 -FilePath .\validatePath.ps1  -ArgumentList $filename,$user -AsJob

while($responSEObject.State -ne "Completed")
{

}

$result = Receive-Job -Id $responSEObject.Id -Keep
echo $result


$filename = "C:\saddfasdfj"

#Here I run the command again,using a different file name
$responSEObject = Invoke-Command CAPTESTPK01 -FilePath .\validatePath.ps1  -ArgumentList $filename,$user -AsJob

while($responSEObject.State -ne "Completed")
{
   if($responSEObject.State -eq "Failed")
   {
        echo "Failed"
        $result = Receive-Job -Id $responSEObject.Id -Keep
        echo $result
        break
   }
}

$result = Receive-Job -Id $responSEObject.Id -Keep
echo $resul

当在validatePath.ps1中使用echo时，它给我这个输出：

C:\Users
This
Blaine
This is the file name: C:\Users
This is the second part
This is the third part
This is user: Blaine <---- This line is here
C:\Users
found!
This is the file name: C:\saddfasdfj
This is user: Blaine <---- But Now it's here,where it should be? Wth?
Blaine,the path C:\saddfasdfj does not exist!