Powershell iterate System.Object

Question

I am using OpenShift CLI in a PowerShell Script,

I have a variable $ProjectList with Data. Not sure of its datatype, but doing $ProjectsList.GetType() gives me below

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array

Looking for a way to Get Name field whose status is running

NAME                                             READY   STATUS             AGE
Service One                                     0/1     Completed            13d
Service Two                                     0/1     Running              13d
Service 3                                       0/1     Running              13d
Service 4                                       0/1     Completed            13d

$ProjectList.Length give me the value 5.

I am looking for a way to get the Name whole status is Running. Tried below code but it does not work.

$ProjectsList = c:\TEMP\oc.exe get pods
$FilteredList = $ProjectList.Where{ $_.STATUS -eq 'Running' }

write-host $FilteredList //This shows empty

Can you help me with some pseudo code.

"I have a variable $ProjectList with Data. Not sure of its datatype" - where did you obtain the data? How did it make its way into `$ProjectList`? :) — Mathias R. Jessen, Apr 14 '22 at 15:32
Santi's comment should fix your problem. Also, you can use `Where-Object`, or it's partner the `.Where({})` operator to filter for that info instead of a loop: `$ProjectList.Where{ $_.Status -eq 'Running' }`. Here's the same using the cmdlet instead: `$ProjectList | Where "Status" -eq "Running"`. — Abraham Zinala, Apr 14 '22 at 15:57
I am using OpenShift OC CLI to get some data from OpenShift clusters. The above Where clause does not work. Edited the code to show the OC command that I use to get data — Riley, Apr 14 '22 at 16:09
@RPK You have not addressed the incorrect usage of `==` in your code above. The correct operator for comparing equality is `-eq`. — codewario, Apr 14 '22 at 16:13
I have removed the If condition and also forloop, the where condition does not return any filtered data. — Riley, Apr 14 '22 at 16:17

zett42 · Accepted Answer · 2022-04-14T20:33:18.743

Your query does not work because the CLI outputs table format by default. So your $ProjectList just contains the formatted text output as an array of strings, which PowerShell does not understand.

According to the docs, the CLI is able to output JSON format, by passing argument -o json. This can easily be parsed into actual objects by using PowerShell's ConvertFrom-Json cmdlet:

$ProjectsList = c:\TEMP\oc.exe get pods -o json | Out-String | ConvertFrom-Json

$FilteredList = $ProjectList.Where{ $_.STATUS -eq 'Running' }

The Out-String call is there because ConvertFrom-Json works best (most predictably¹) when given a single input string. When redirecting the output of a native process, you would normally get each line one-by-one, as a separate string. Using Out-String makes sure that the next command in the pipeline receives the output as a single multiline string instead.

^{1) See this answer for pitfalls when passing multiple strings to ConvertFrom-Json.}

Powershell iterate System.Object

1 Answers1