I have a pretty basic PowerShell array: $TestArray with 2 text columns: Price and TimeStamp (that's the way I get them, nothing to be done about this):
Price TimeStamp
----- ----------------
0.0567 1542056680.72746
0.0567 1542056650.34414
0.0555 1542056197.46668
0.0551 1542056167.28967
I would like, in a single PowerShell line to add a rounded Time2 value
$Time2 = [math]::Round($TestArray.TimeStamp)
The code I am thinking of is:
$TestArray | Add-Member -Name Time2 -MemberType NoteProperty -Value { [math]::Round($Table.TimeStamp) }
Of course, I can do a ForEach loop; it would take care of it easily, but I would like to achieve this in this single line of code.
Any idea ?
Cheers,
Philippe
Mathias R. Jessen's answer directly solves your problem, by creating a script property (type ScriptProperty) that dynamically calculates its value from the enclosing object's .TimeStamp property.
The advantage of this approach is that even later changes to .TimeStamp will correctly be reflected in .Time2, albeit at the cost of having to calculate the value on every access.
Manuel Batsching's answer offers a Select-Object-based alternative that creates static note properties (type NoteProperty), as you've originally attempted yourself.
The advantage of this approach is that you incur the cost of calculation only once, but later changes to .TimeStamp won't be reflected in .Time2.
To offer faster PSv5+ alternatives (a single method call each, spread across multiple lines for readability):
# ScriptProperty - dynamic
$TestArray.ForEach({
$_.psobject.properties.Add(
[psscriptproperty]::new('Time2', { [math]::Round($this.TimeStamp) })
)
})
# NoteProperty - static
$TestArray.ForEach({
$_.psobject.properties.Add(
[psnoteproperty]::new('Time2', [math]::Round($_.TimeStamp))
)
})
The above solutions use the PSv4+ .ForEach() collection method and the PSv5+ static ::new() type method for calling constructors.
Finally, re one-liner:
The following foreach-loop based note-property solution would have solved your problem too, and would have been faster; while it is spread across multiple lines for readability here, it also works as a one-liner:
foreach ($el in $TestArray) {
Add-Member -InputObject $el -Name Time2 -MemberType NoteProperty `
-Value ([math]::Round($el.TimeStamp))
}
Generally, while the pipeline often enables more elegant, single-command solution, that - unfortunately - comes at the expense of performance.
Alternatively you can achieve the same with Select-Object and a custom property:
$TestArray | Select-Object *,#{ n='Time2';e={ [math]::Round($_.TimeStamp) }}
Change the member type to ScriptProperty and refer to the individual array item as $this:
$TestArray |Add-Member Time2 -Value { [math]::Round($this.Timestamp) } -MemberType ScriptProperty
Worth noting that in this example, the pipeline itself acts as a foreach loop, unravelling the array and binding each individual item to Add-Member
Related
I'm trying to write a script that checks whether a group of registry keys are set individually and then either sets them or modifies them conditional on thier current state.
The keys that I want to check/set contain a mix of Strings and DWORDs
I want to loop through an array that contains the key I want to set paired with the value.
I've tried as a hashtable/splatting but the input to Get-ItemProperty fails because of the value parameter so I tried basic arrays instead with no luck.
They are all at the same registry path but I was attempting to do something similar to this:
$Path = "HKLM:\Software\path\to\keys"
$Properties = (
('key', value),
('key2', value2),
('key3', 'value3')
)
foreach ($item in $Properties){
$exist = Get-ItemProperty -Path $Path -name $item[0]
if ($exist) {
Set-ItemProperty -Path $Path -Name $item[0] -Value $item[1]
} else {
New-ItemProperty -Path $Path -Name $item[0] -Value $item[1]
}
}
But no matter what I've tried I cannot retrieve the individual elements of the inner arrays.
I realize I could probably do this long-form and just do it line by line rather than attempting to iterate through, but this is definitely a more elegant way, and would be a great template if I need to do something similar in the future.
Holy moly. Nothing breaks you out of a rut like posting the question to an online forum.
The .GetValue() method is what I needed, not the raw index number.
...So $Item.GetValue(0) for the key name and $Item.GetValue(1) for the value.
Feel silly answering my own question but hopefully it helps someone else!
I have a product CSV file that I have imported into $products
If something occurs more than once with the same name I want to populate the ParentSKU field, otherwise leave it blank.
Excuse the pseudocode but I'm imagining something like this:
foreach ($item in $products) {
if ($item.name.count -gt 1) {
$item.ParentSKU = $item.name }
else { } # do nothing
}
$item.name.count isn't correct but I hope my thinking is on the right track?
Many thanks for any advice
Powershell Object lists aren't smart enough to know that there's multiple of any one item, so you're going to have to iterate through (manually or otherwise) to find whether there's multiples here.
Since you're going to be making modifications to any duplicates, it may make sense to loop through and find duplicates manually, but it doesn't really follow the "powershell" philosophy / approach.
If you want to use powershell's built-in & powerful piping features, you might try a solution like this, which would grab all the PSObjects with duplicates using Where-Object, then sets the values for all those PSObjects.
$products |
Group-Object -Property Name |
Where-Object -FilterScript {
$_.Count -gt 1
} |
Select-Object -ExpandProperty Group |
Foreach-Object { $_.ParentSKU = $_.Name }
Since everything is passed by reference, your $products object will have the modified values!
I have an object named $restoreItems that I would like to filter for duplicates property values and select the most recent one.
Please have a look at its members first to understand what I'm working with:
In order to be able to check for duplicates I need a combination of the 'DirName' + 'LeafName' properties as this combination builds a complete file path.
This is my first issue. I am not able to combine the two properties and add it to that object. I tried to add a new member like so:
$restoreItems | Add-Member -NotePropertyName fullPath -NotePropertyValue
($restoreItems.Dirname + '/' + $restoreItems.LeafName)
This command runs fine but upon calling
$restoreItems.fullPath
I get an error stating 'Array dimensions exceeded supported range.'
Is there another way to add $restoreItems.Dirname + '/' + $restoreItems.LeafName to the object? If so I could probably find a way to exclude duplicates according to their DeletedDate property.
Thanks for your help.
Edit: Here's .GetType() for the object:
Your statement
($restoreItems.Dirname + '/' + $restoreItems.LeafName)
builds an array of all dirnames, the string "\", and all leafnames.
What you actually want is something like this:
$restoreItems | ForEach-Object {
$fullname = Join-Path $_.DirName $_.LeafName
$_ | Add-Member -Type NoteProperty -Name FullName -Value $fullname
}
Description: I'm building a PowerShell-script that searches for files, then gives them unique names, copies them and then verifies them via hash-calculation - I chose to split the script in functions for each step, so it's easier to maintain the whole thing.
To get all values from one function to the other, I chose to use [hashtable]$FooBar - inside $FooBar, there are multiple arrays, such as FullName or OutputPath (which may change per file as they will be copied to subfolders named yyyy-mm-dd). All arrays are correlating with each other (meaning that index 1 contains all values of the first file, index 2 the values for the second file,...) and this works fine as of now.
A short simplified visualisation:
$FooBar = #{}
$FooBar.FullName = #()
$FooBar.Size = #()
$FooBar.Ext = #()
Get-ChildItem | ForEach-Object {
$FooBar.FullName += $_.FullName
$FooBar.Size += $_.Length
$FooBar.Ext += $_.Extension
}
However, I now need to sort them all by one value-set of one of the arrays, e.g. the size. Or, visualised again:
# From:
$FooBar
Name Value
---- -----
fullname {D:\AAA.XYZ, D:\BBB.ZYX, D:\CCC.YZX}
size {222, 111, 555}
extension {.XYZ, .ZYX, .YZX}
# To:
$FooBar = $FooBar | Sort-Object -Property Size -Descending
$FooBar
Name Value
---- -----
fullname {D:\CCC.YZX, D:\AAA.XYZ, D:\BBB.ZYX}
size {555, 222, 111}
extension {.YZX, .XYZ, .ZYX}
I tried $FooBar.GetEnumerator() | Sort-Object -Property Size, but this does not change anything. Google turned up suggestions on how to sort an array of hashtables, but in my case, it's the other way round, and I can't get my head around this because I don't even understand why this is a problem in the first place.
So my question is: is there any way to sort all arrays inside the hashtable by the value-set of one of the arrays? I can't get my head around this.
Disclaimer: I'm a PowerShell-autodidact with no reasonable background in scripting/programming, so it might well be that my "include everything in one hashtable"-solution isn't going to work at all or might be extremely inefficient - if so, please tell me.
The easiest way to go about what I believe you are trying to do is Select-Object
$fooBar = Get-ChildItem | Select-Object FullName, Size, Extension
This will create an array of new objects that only have the desired properties. The reason this works and your method doesn't is because Sort-Object works on properties and the property you are specifying is behind a few layers.
If you need more flexibility than just exact properties, you can create your own like this
$fooBar = Get-ChildItem | Select-Object #{Name = 'SizeMB'; Expression = {$_.Size / 1MB}}
Or manually create new properties with the [PSCustomObject] type accelerator:
$fooBar = Get-ChildItem | ForEach-Object {
[PSCustomObject]#{
FullName = $_.FullName
Extension = $_.Extension
Size = $_.Size
}
}
Update
If you need to add additional properties to the object after it's initially created you have a few options.
Add-Member
The most common method by far is by using the Add-Member cmdlet.
$object | Add-Member -MemberType NoteProperty -Name NewProperty -Value 'MyValue'
$object
Something important to keep in mind is that by default this cmdlet does not return anything. So if you place the above statement at the end of a function and do not separately return the object, your function won't return anything. Make sure you either use the -PassThru parameter (this is also useful for chaining Add-Member commands) or call the variable afterwards (like the example above)
Select-Object
You can select all previous properties when using calculated properties to add members. Keep in mind, because of how Select-Object works, all methods from the source object will not be carried over.
$fooBar | Select-Object *, #{Name = 'NewProperty'; Expression = {'MyValue'}}
psobject.Properties
This one is my personal favorite, but it's restricted to later versions of PowerShell and I haven't actually seen it used by anyone else yet.
$fooBar.psobject.Properties.Add([psnoteproperty]::new('NewProperty', 'MyValue'))
$fooBar
Each member type has it's own constructor. You can also add methods to $fooBar.psobject.Methods or either type to $fooBar.psobject.Members. I like this method because it feels more explicit, and something about adding members with members feels right.
Summary
The method you choose is mostly preference. I would recommend Add-Member if possible because it's the most used, therefore has better readability and more people who can answer questions about it.
I would also like to mention that it's usually best to avoid adding additional members if at all possible. A function's return value should ideally have a reliable form. If someone is using your function and they have to guess when a property or method will exist on your object it becomes very difficult to debug. Obviously this isn't a hard and fast rule, but if you need to add a member you should at least consider if it would be better to refactor instead.
For all practical purposes I'd strongly suggest you just store the objects you need in a single array, sort that once and then reference the individual properties of each object when needed:
$FooBar = Get-ChildItem |Sort-Object -Property Length
# Need the Extension property of the object at index 4?
$FooBar[4].Extension
To answer your actual question:
Array.Sort() has an overload that takes keys and values arrays separately. You could make a copy of the array you want to sort on for each other property you want to sort:
# Create hashtable of correlated arrays
$FooBar = #{}
$FooBar.FullName = #()
$FooBar.Size = #()
$FooBar.Ext = #()
# Types cast explicitly to avoid Array.Sort() calling .CompareTo() on the boxing object
Get-ChildItem | ForEach-Object {
$FooBar.FullName += [string]$_.FullName
$FooBar.Size += [int]$_.Length
$FooBar.Ext += [string]$_.Extension
}
# Define name of reference array property
$SortKey = 'Size'
# Sort all arrays except for the reference array
$FooBar.Keys |Where-Object {$_ -ne $SortKey} |ForEach-Object {
# Copy reference values to new array
$Keys = $FooBar[$SortKey].Clone()
# Sort values in target array based on reference values
[array]::Sort($Keys,$FooBar[$_])
}
# Finally sort the reference array
[array]::Sort($FooBar[$SortOn])
The above only works as long as the reference array is made up of value types
PowerShell makes working with objects ridiculously easy.
Try:
$FooBar = Get-Childitem
$FooBar | Get-Member
This will tell you that $Foobar actually contains objects of FileInfo and DirectoryInfo type, and show you the Properties available.
$FooBarSortedBySizeDesc = $FooBar | Sort-Object Length -Descending
$FooBarFullNamesOnly = $FooBar.FullName
I have a single dimensional array that I get from either a get-content command or from multi-line text box input. I want to assign a property to the entries in this array, then add more properties to use later in my script.
Something like:
$items = new-object psobject
$items | add-member -membertype NoteProperty –name Name –value NotSet
$items | add-member -membertype NoteProperty –name Percent –value NotSet
$names = #($textboxInputText.Lines)
$names | % { $items | Add-Member noteproperty $_.Name $temp.($_.Name) }
foreach ($item in $items)
{
$percent = {script block}
$item.percent = $percent
}
I know this is broken code, but I wanted to give an example of where I was headed. I've searched far and wide but haven't been able to find exactly what I was looking for.
EDIT:
Code Goal: Get input from a text box or text file (single line entries). Have those entries be assigned to the "name" property, then add a second property to the array (Percent) that will need to be filled in with another block of code.
EDIT 2:
Collection is being used in the following code:
foreach ($item in $collection) {
$psConsoleFile = "PATH TO FILE.pc1"
$variable1 = "something"
$variable2 = "something else"
$command = ".`"Command1 $item.name | Command2 -Switch $variable1 -Switch2 $variable2`""
$OutputScriptBlock = "powershell.exe -PSConsoleFile $psConsoleFile -command $command"
}
The output of this is as follows:
powershell.exe -PSConsoleFile "PATH TO FILE.psc1" -command ."Command1 #{Name=name1; Percentage=}.name | Command2 -Switch1 something"
Why is the code outputting the full row instead of the name?
Also, I'm using PS 4.0 for all implementations of this script.
Ok, I see the problem here. So you have an array of Strings that you got either from a multi-line text box form object, or from a text document with the Get-Content command, but what you really want is an array of PSObjects.
A string object can not have additional properties added to it like you want (well, not conventionally, let's just not go there because you won't be happy with where things end up, trust me on this one). Instead let's take that array of strings, and for each string create a PSObject for it like you want. You will want a ForEach-Object loop for this to be simple. Either way you will want to pipe your input (either the textbox or the get-content command) to a ForEach loop, and you can assign the whole thing to a variable that will collect all of the objects to be worked with later (to update the Percent property). Something like this should accomplish what you want:
[Array]$Collection = $textboxInputText.Lines | ForEach{
New-Object PSObject -Property #{
'Name' = $_
'Percentage' = $null
}
}
I specified $Collection as the type [Array] so that if you wanted to index into it later there wouldn't be any issues should your input only be a single item. Then if you want to update the percentages you can do that by running $Collection through a ForEach loop (either inline or not)
$Collection | ForEach{ $_.Percentage = {Script Block} }
or
ForEach($Item in $Collection){
$Item.Percentage = {Script Block}
}
Now, things to note here... You are not going to be able to just assign $Collection back to your textbox. You could probably assign $Collection.Name, but that may require a newer version of PS since I don't know how backwards compatible that is. If you use a Get-Content command instead of referencing the textbox, simply change $textboxInputText.Lines | ForEach{ to Get-Content "C:\Path\To\File.txt" | ForEach{ and you should be all set.
Edit: Ok, the problem you have now isn't with the object but with how you're trying to expand a property of it within a double quotes. To access the name you would have to create a sub expression within the double quotes by wrapping $Item.Name within $(). So that line for you would look like:
$command = ".`"Command1 $($item.name) | Command2 -Switch $variable1 -Switch2 $variable2`""