Jenkins parametrized build - read file in powershell - powershell

Question

I'm trying to create a Jenkins Parametrized build using the file parameter.
The user will select build with parameters, and will supply a text document with a list of items (one per line).
I would like to try and read this list in my powershell script to then go off and make some service calls (I've got that bit sussed).
I'm struggling with getting my powershell script to read the file that has been passed into Jenkins, here is what I have so far
$ids = Import-Csv input.txt
$array = #()
Write-Host $array.Length
foreach($id in $ids){
Write-Host $id.id
$array += $id
Write-Host "Array now has" $array.Length "items"
}
I know the script is running OK as I can run in Powershell ISE and pass in the absolute path of the csv/txt file.
For reference, the content of input.txt is like this:
id
2884430041011214,
9751297519392363,
lfsdkjgskdjflgsdjfg
Here are the two outputs I get for
Powershell ISE (as expected):
0
2884430041011214
Array now has 1 items
9751297519392363
Array now has 2 items
lfsdkjgskdjflgsdjfg
Array now has 3 items
Jenkins (not what I'm hoping for)
Started by user anonymous
Building in workspace C:\Users\jonec34\.jenkins\jobs\getParty\workspace
[workspace] $ powershell.exe -NonInteractive -ExecutionPolicy ByPass "& 'C:\Users\jonec34\AppData\Local\Temp\hudson4035619350462822370.ps1'"
Import-Csv : Could not find file 'C:\Users\jonec34\.jenkins\jobs\getParty\workspace\input.txt'.
At C:\Users\jonec34\AppData\Local\Temp\hudson4035619350462822370.ps1:1 char:8
+ $ids = Import-Csv input.txt
+ ~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : OpenError: (:) [Import-Csv], FileNotFoundException
+ FullyQualifiedErrorId : FileOpenFailure,Microsoft.PowerShell.Commands.ImportCsvCommand
0
Finished: SUCCESS
Can anyone tell me how I can do this please. I've also tried putting Param($file) at the start of the script, and using ${WORKSPACE} but either they're not working or I'm not understanding it properly. Any help greatly appreciated.
Thanks

Answer 1

Right, I've found where I was going wrong...
In my file parameter, I hadn't set a file location (EG I'd left it blank), but I entered in '\input.txt' and low and behold I get
Building in workspace C:\Users\jonec34\.jenkins\jobs\getParty\workspace
Copying file to \input.txt
[workspace] $ powershell.exe -NonInteractive -ExecutionPolicy ByPass "& 'C:\Users\jonec34\AppData\Local\Temp\hudson6216657038417634126.ps1'"
getting requests from file
0
2884430041011214
Array now has 1 items
9751297519392363
Array now has 2 items
lfsdkjgskdjflgsdjfg
Array now has 3 items
Finished: SUCCESS