Recently I was given a task for writing a powershell script which does some DELETION of blob objects, but the challenge was to keep this script minimal and mostly limited to a one liner.
I know, you won’t call a one liner as a script, but instead a command.
So, I took this challenge and started dewlling into “How we can iterate over a list of objects in a single line with Powershell“
Yes, I know its possible by just writing a the for loop syntax in a single line like this, but we are going to do it using pipe operator. So we cannot use a regular For Loop syntax in this case.
We can do it 2 ways.
Lets suppose, we are trying to list files in a directory
D:\Navin\test> Get-ChildItem .
Directory: D:\Navin\test
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a---- 8/27/2019 9:47 PM 0 test1 - Copy.txt
-a---- 8/27/2019 9:47 PM 0 test1.txt
-a---- 8/27/2019 9:47 PM 0 test2.txt
-a---- 8/27/2019 9:47 PM 0 test3.txt
Based on the output, we can use ForEach-Object along with a pipeline operator here to pass the result of first command to second command as input. At the same time, you can refer to $_. as the current element of list, while iterating in loop.
D:\Navin\test> Get-ChildItem | ForEach-Object {write-host $_.Name}
test1 - Copy.txt
test1.txt
test2.txt
test3.txt
Other way of doing this is by using a % symbol instead of ForEach-Object, this does exactly the same thing, but is a more shorter version.
D:\Navin\test> Get-ChildItem | % {write-host $_.Name}
test1 - Copy.txt
test1.txt
test2.txt
test3.txt
That is how we can iterate over a result (list) in a single line of powershell.
Go ahead and explore this by yourself, you will be amazed to know, how easy it is.
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