Start function as a background job with start-job

Question

I am trying to start a function with start-job. For some reason, I cannot get it to work, the global variables wont pass. My question would be - how to pass global variables to the function and than to start-job without declaring them inside the function. Function example:

 $OutputDirectory=c:\test
 $zipfile="c:\1.zip"

    function 7zipextraction
{
    Set-Alias 7zip $7zip_path
    # Extracting files
    $extract = 7zip x -y $zipfile -o"$OutputDirectory"
    if ($LASTEXITCODE -ne 0)
    {
        
        write-host "7zip Error"
        
        return
    }
    else
    {
        write-host "Files extracted successfully"
    }
    Start-Sleep -s 2
    
}

Examples from start-job:

Start-Job -ScriptBlock ${Function:7zipextraction} | Wait-Job | Receive-Job

Answer 1

You can use the using: modifier to access variables that are outside your script block:

$OutputDirectory='c:\test'
$zipfile='c:\1.zip'
$7zippath = 'C:\path\to\7zip'

function 7zipextraction
{
    Set-Alias 7zip $using:7zippath
    # Extracting files
    $extract = 7zip x -y $using:zipfile -o"${using:OutputDirectory}"
    if ($LASTEXITCODE -ne 0)
    {
        
        write-host "7zip Error"
        
        return
    }
    else
    {
        write-host "Files extracted successfully"
    }
    Start-Sleep -s 2
    
}

Start-Job -ScriptBlock ${Function:7zipextraction} | Receive-Job -Wait -AutoRemoveJob

using works with script blocks executed on remote computers or in a different thread:

• Invoke-Command
• Start-Job
• Start-ThreadJob
• ForEach-Object -Parallel