powershell 不等待命令完成？

Question

I have a command which gets md5 sum's of a bunch of files which takes a bit - it seems like powershell is NOT waiting for this command to finish before moving on to the rest of the script?? is that possible?

Script:

$localmd5 = Get-ChildItem "C:\Users\Tony\Pictures\My Pictures\Tony\Automatic Upload\Tony’s iPhone" -Recurse -File | 
            select-object name, fullname, 
                @{Name = "MD5"; Expression = {(Get-FileHash $_.FullName -Algorithm MD5).Hash}}

$localmd5=$localmd5 | Select-Object -Property MD5 -ExpandProperty MD5 -First 10
Write-Output "got local md5's"
$null -eq $localmd5


$remotemd5=rclone md5sum remote:"My Pictures\Tony\Automatic Upload\Tony’s iPhone" --dry-run
$remotemd5=$remotemd5.foreach({($_ -split '\s+')[0]})
Write-Output "got remote md5's"
Write-Output $remotemd5

Write-Output "checking for diffs..."
$diffmd5=Compare-Object -ReferenceObject $localmd5 -DifferenceObject $remotemd5 -IncludeEqual
Write-Output $diffmd5 

It never completes the first md5sum action on the first line before finding that the variable localmd5 is null... what gives?

UPDATE 1:

PS C:\Users\Tony> Test-Path "C:\Users\Tony\Pictures\My Pictures\Tony\Automatic Upload\Tony’s iPhone"

True

PS C:\Users\Tony> $ErrorActionPreference

Continue


PS C:\Users\Tony> $PSVersionTable | Select-Object -Property PSVersion


PSVersion
---------

ERROR MSG:

Compare-Object : Cannot bind argument to parameter 'ReferenceObject' because it is null.
At C:\Users\Tony\Documents\pcloud_sync.ps1:13 char:42
+ $diffmd5=Compare-Object -ReferenceObject $localmd5 -DifferenceObject  ...
+                                          ~~~~~~~~~
    + CategoryInfo          : InvalidData: (:) [Compare-Object], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.CompareObjectCommand

Update 2

PS Version output

Name                           Value
----                           -----
PSVersion                      5.1.19041.610
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.19041.610
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

Line 1 command works alone but when running in the script the variable NEVER gets set for some reason... here it is just the command running

    PS C:\Users\Tony> Get-ChildItem "C:\Users\Tony\Pictures\My Pictures\Tony\Automatic Upload\Tony’s iPhone" -Recurse -File | 
>>             select-object name, fullname,
>>                 @{Name = "MD5"; Expression = {(Get-FileHash $_.FullName -Algorithm MD5).Hash}}


Name                     FullName                                                                                        MD5
----                     --------                                                                                        ---
2019-11-02 09-03-25.jpeg C:\Users\Tony\Pictures\My Pictures\Tony\Automatic Upload\Tony’s iPhone\2019-11-02 09-03-25.jpeg 80DE8D1C0D55AE3FC21279A15D29C582
2020-02-18 14-29-28.heic C:\Users\Tony\Pictures\My Pictures\Tony\Automatic Upload\Tony’s iPhone\2020-02-18 14-29-28.heic 98745AFC6F415AEC96DD673F675F47BA

Answer 1

When I've had similar issues, opening the script in Notepad++ and using either Show All Characters or viewing the state in the Encoding menu has been helpful.

It is also possible to do a quick test like this

[int][char] 'x'

120

• Understanding file encoding in VS Code and PowerShell - PowerShell | Microsoft Docs

Answer 2

FINALLY figured out what this issue was - running the debugger in powershell and comparing the script vs the manual command this like caught my eye:

DEBUG:    1+  >>>> $localmd5 = Get-ChildItem "C:\Users\Tony\Pictures\My Pictures\Tony\Automatic Upload\Tony’s iPhone"
 -Recurse -File

Tony’s should be Tony's the freaking issue was BOM and not using UTF8 BOM in my script, - fixed that up. re-saved and it worked without issue.