Working with jobs in Powershell

Question

 $contacts1 = Import-Csv "C:\temp\gal\gal1.csv"
       Start-Job -Name Loop1 -ScriptBlock {
           param([string[]]$contacts1)
            foreach ($c1 in $contacts1){
               $name = $c1.displayname
               New-Item -Path "C:\Temp\GAL" -Name "$name"  -ItemType "file"
           }
       } -ArgumentList (,$contacts1)
       Wait-Job -Name Loop1 | Receive-Job
       Get-Job -Name Loop1 | Remove-Job

The above is creating one file with the name created from inside the CSV but then the next three loops just try and create that same name. But if I comment out all the stuff to do with jobs, as below, the loop itself creates the four files with correct names successfully.

$contacts1 = Import-Csv "C:\temp\gal\gal1.csv"
#Start-Job -Name Loop1 -ScriptBlock {
    #param([string[]]$contacts1)
     foreach ($c1 in $contacts1){
        $name = $c1.displayname
        New-Item -Path "C:\Temp\GAL" -Name "$name"  -ItemType "file"
    }
#} -ArgumentList (,$contacts1)
#Wait-Job -Name Loop1 | Receive-Job
#Get-Job -Name Loop1 | Remove-Job

Answer 1

In the first one you work with strings (you pass a string array to the job). Strings does not have a displayname property. The first block will probably raise an error with strict mode (Set-StrictMode -Version "latest"). You will have to pass an array of objects (that have a displayname property) for this to work.

In the second you work with the objects produced by Import-CSV. The return value of Import-Csv depends on the content of the file. The file probably contains a "#TYPE" line and a header line if you used Export-Csv. One of your headers is probably "displayname".

Example:

PS C:\> Get-ChildItem -Filter "windows" | Select-Object "FullName","Name" | Export-Csv -Path "c:\myfolder\test.csv"

PS C:\> Get-Content ".\myfolder\test.csv"
#TYPE Selected.System.IO.DirectoryInfo
"FullName","Name"
"C:\Windows","Windows"

PS C:\> Import-Csv -Path "C:\myfolder\test.csv"

FullName   Name   
--------   ----   
C:\Windows Windows

PS C:\> (Import-Csv -Path "C:\myfolder\test.csv").fullname
C:\Windows

Edit:

This might depend on the content of the csv (which isn't provided). But your example with jobs will probably work if you just change the parameter type. Like this:

 $contacts1 = Import-Csv "C:\temp\gal\gal1.csv"
       Start-Job -Name Loop1 -ScriptBlock {
           param([pscustomobject[]]$contacts1)
            foreach ($c1 in $contacts1){
               $name = $c1.displayname
               New-Item -Path "C:\Temp\GAL" -Name "$name"  -ItemType "file"
           }
       } -ArgumentList (,$contacts1)
       Wait-Job -Name Loop1 | Receive-Job
       Get-Job -Name Loop1 | Remove-Job