PowerShell 中的 echo 和 Write-Host 有什麼區別？

我對PowerShell之間echo的區別感到困惑。Write-Host我有兩個文件，POC.ps1& validatePath.ps1。這些文件在我的本地機器上，我正在使用Invoke-Command. 我正在使用 PowerShell v3.0。

要執行這兩個腳本，我使用以下命令：

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

這是兩個文件：

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

這就是事情變得奇怪的地方……

驗證路徑.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
}

當我執行上面的腳本時，這是輸出：

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，如果我將其更改validatePath.ps1為：

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

function ValidatePath( $filename, $user, $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
}

這是輸出：

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!

您會注意到“這是使用者：”這一行位於不同的位置。為什麼是這樣？為什麼echo工作方式與 不同Write-Host？

更新：

更奇怪的是，如果我像這樣重新執行腳本兩次：

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

echo在使用時它給了我這個輸出validatePath.ps1：

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!

echo是 的別名Write-Output，它寫入 Success 輸出流。這允許通過管道處理輸出或將輸出重定向到文件中。Write-Host直接寫入控制台，因此無法進一步重定向/處理輸出。

引用自：https://stackoverflow.com/questions/17623644