PowerShell-通过Invoke-Command发送变量

Question

I have 3 Windows 2016 servers and some routine task I want to automate. I'm newbie in PowerShell, so I spent a lot of time looking for answer in StackOverflow and "googling".

My task is to backup some files via 7zip on remote server.

There are is a command which works great:

Invoke-Command -ComputerName 10.10.0.20 -ScriptBlock {start-Process  -wait-FilePath 'C:\Program Files\7-Zip\7z.exe' -ArgumentList 'a','-t7z','C:\BlueCollar_backup\bluecollar_121.zip','C:\Services\BlueCollar' -wait}

But I need to add date to bluecollar_121.zip archive name, it should look like bluecollar_13.08.2018.zip

I've tried a huge amount of variants but with no luck.

[string]$stime = get-date -f 'dd.MM.yyyy
Invoke-Command -ComputerName 10.10.0.20 -ScriptBlock {start-Process -FilePath 'C:\Program Files\7-Zip\7z.exe' -ArgumentsList 'a -t7z C:\BlueCollar_backup\bluecollar_'$stime'.zip C:\Services\BlueCollar' -wait}

Second try was:

[string]$stime = get-date -f 'dd.MM.yyyy
[string]$tmp1="C:\BlueCollar_backup\bluecollar_$stime.zip"
$command = {start-Process -FilePath 'C:\Program Files\7-Zip\7z.exe' -ArgumentsList 'a -t7z $stime C:\Services\BlueCollar' -wait}

And the last try:

[string]$stime = get-date -f 'dd.MM.yyyy
$arguments = @()
$arguments += "a"
$arguments += "-t7z"
$arguments +=  "$tmp1"
$arguments +=  "C:\Services\BlueCollar"
Invoke-Command -ComputerName 10.10.0.20 -ScriptBlock {start-Process -FilePath 'C:\Program Files\7-Zip\7z.exe' -ArgumentList($arguments) -wait}

They all aren't working. The problem is $stime variable. How can I put variable $stime into Invoke-Command ?

UPD1: I solved that problem!

Invoke-Command -ComputerName '10.10.0.20' -ArgumentList  $stime -ScriptBlock{
$stime = $args[0]
start-Process -FilePath 'C:\Program Files\7-Zip\7z.exe' "a -t7z C:\BlueCollar_backup\bluecollar_$stime.zip C:\Services\BlueCollar" -wait
}

Answer 1

The problem is that the computer you are executing the command from knows about the $stime variable, but the remote computer doesn't know it. So you have to pass it in.

There are a couple options, one is to use the $Using variable

[string]$stime = get-date -f 'dd.MM.yyyy
Invoke-Command -ComputerName 10.10.0.20 -ScriptBlock {
    start-Process -FilePath 'C:\Program Files\7-Zip\7z.exe' -ArgumentsList "a -t7z C:\BlueCollar_backup\bluecollar_$($Using:stime).zip C:\Services\BlueCollar" -wait
}

Another option that is perhaps a little cleaner looking is to make your ScriptBlock a string of text, and then pass it to the remote computer:

$ScriptBlock=[ScriptBlock]::Create("start-Process -FilePath 'C:\Program Files\7-Zip\7z.exe' -ArgumentsList 'a -t7z C:\BlueCollar_backup\bluecollar_$stime.zip C:\Services\BlueCollar'")
Invoke-Command -ComputerName 10.10.0.20 -ScriptBlock $ScriptBlock

An important distinction is between single quotes and double quotes. When you use single quotes, it resolves text exactly as is. When you use double quotes, it resolves variables.