I have a hashtable created from an array like this:
$employeesHashtable = $employees | Group-Object -Property Initials -AsHashTable
How do I find keys having multiple values?
The alternative to using .GetEnumerator() can be using the hash table Keys, the key collection implements ICollection and can be enumerated without issues:
$keysWithMultipleValues = $employeesHashtable.Keys.where{ $employeesHashtable[$_].Count -gt 1 }
I ended up with this:
$keysWithMultipleValues = $employeesHashtable.GetEnumerator() | `
ForEach-Object { [PSCustomObject]#{ Key = $_.Key; Count = $_.Value.Count } } | `
Where-Object { $_.Count -gt 1 }
Related
I keep running into the same problem again, and i have my default way of handling it, but it keeps bugging me.
Isn't there any better way?
So basicly i have a pipline running, do stuff within the pipline, and want to return a Key/Value Pair from within the pipline.
I want the whole pipline to return a object of type psobject (or pscustomobject).
Here is the way i do it everytime.
I create a hashtable at the beginning of the pipline and add key/Value Pairs from within the pipline to this hashtable using the .Add() method.
Afterwards i create a psobject by passing the hashtbale to New-Object`s -Property Parameter. This gives me the desired result.
Get-Process | Sort -Unique Name | ForEach-Object -Begin { $ht = #{} } -Process {
# DO STUFF
$key = $_.Name
$val = $_.Id
# Add Entry to Hashtable
$ht.Add($key,$val)
}
# Create PSObject from Hashtable
$myAwesomeNewObject = New-Object psobject -Property $ht
# Done - returns System.Management.Automation.PSCustomObject
$myAwesomeNewObject.GetType().FullName
But this seems a bit cluncky, isn't there a more elegant way of doing it?
Something like this:
[PSObject]$myAwesomeNewObject = Get-Process | Sort -Unique Name | ForEach-Object -Process {
# DO STUFF
$key = $_.Name
$val = $_.Id
# return Key/Val Pair
#{$key=$val}
}
# Failed - returns System.Object[]
$myAwesomeNewObject.GetType().FullName
This unfortunally dosn't work, since the pipe returns an array of hashtables, but i hope you know now what iam trying to achieve.
Thanks
Not sure if this is more elegant but just another way of doing it, this uses an anonymous function so $ht will no longer be available after execution, and casts to [pscustomobject] instead of using New-Object:
[pscustomobject] (Get-Process | Sort -Unique Name | & {
begin { $ht = #{ } }
process {
# DO STUFF
$key = $_.Name
$val = $_.Id
# Add Entry to Hashtable
$ht.Add($key, $val)
}
end { $ht }
})
You can also use the -End parameter to convert the final hash table to a pscustomobject as part of the pipeline, without needing to set the whole thing to a variable
$ht[$key]=$val is also a nice shorthand for $ht.Add($key,$val):
Get-Process |
Sort -Unique Name |
Foreach -Begin { $ht = #{} } -Process {
$ht[$_.Name] = $_.Id
} -End {[pscustomobject]$ht} |
## continue pipeline with pscustomobject
Thanks to #Santiago Squarzon and #Cpt.Whale answers, i were able to combine them to create a solution that pleases me:
$myAwesomeNewObject = `
Get-Process | Sort -Unique Name | & {
begin { $ht = #{} }
process {
# DO STUFF
$key = $_.Name
$val = $_.Id
# Add Entry to Hashtable
$ht[$key]=$val
}
end {[pscustomobject]$ht}
}
# Success - System.Management.Automation.PSCustomObject
$myAwesomeNewObject.Gettype().FullName
# And helper Hashtable is NULL thanks to the
# anonym function
$null -eq $ht
Thanks alot Guys
Alternatively you may create a hashtable using Group-Object -AsHashTable:
# Store the PIDs of all processes into a PSCustomObject, keyed by the process name
$processes = [PSCustomObject] (Get-Process -PV proc |
Select-Object -Expand Id |
Group-Object { $proc.Name } -AsHashtable)
# List all PIDs of given process
$processes.chrome
Notes:
Common parameter -PV (alias of -PipelineVariable) makes sure that we can still access the full process object from within the calculated property of the Group-Object command, despite that we have a Select-Object command in between.
The values of the properties are arrays, which store the process IDs of all instances of each process. E. g. $processes.chrome outputs a list of PIDs of all instances of the chrome process.
Is it possible to display the results of a PowerShell Compare-Object in two columns showing the differences of reference vs difference objects?
For example using my current cmdline:
Compare-Object $Base $Test
Gives:
InputObject SideIndicator
987654 =>
555555 <=
123456 <=
In reality the list is rather long. For easier data reading is it possible to format the data like so:
Base Test
555555 987654
123456
So each column shows which elements exist in that object vs the other.
For bonus points it would be fantastic to have a count in the column header like so:
Base(2) Test(1)
555555 987654
123456
Possible? Sure. Feasible? Not so much. PowerShell wasn't really built for creating this kind of tabular output. What you can do is collect the differences in a hashtable as nested arrays by input file:
$ht = #{}
Compare-Object $Base $Test | ForEach-Object {
$value = $_.InputObject
switch ($_.SideIndicator) {
'=>' { $ht['Test'] += #($value) }
'<=' { $ht['Base'] += #($value) }
}
}
then transpose the hashtable:
$cnt = $ht.Values |
ForEach-Object { $_.Count } |
Sort-Object |
Select-Object -Last 1
$keys = $ht.Keys | Sort-Object
0..($cnt-1) | ForEach-Object {
$props = [ordered]#{}
foreach ($key in $keys) {
$props[$key] = $ht[$key][$_]
}
New-Object -Type PSObject -Property $props
} | Format-Table -AutoSize
To include the item count in the header name change $props[$key] to $props["$key($($ht[$key].Count))"].
I have a hash table as below:
$Hash = #{
Team1=$Team1.count
Team2=$Team2.count
Team3=$Team3.count
}
$GroupByTeam = New-Object psobject -Property $Hash |
Select 'Team1','Team2','Team3' | ConvertTo-Html -Fragment
This is fine and each "team" returns their own value. However, teams may have a null value and I wish to substitute this for "0".
In an attempt to work this out, I have tried to select the null value first but can't seem to do this:
$Hash.values | select -property Values
Values
------
{1, 2}
But
$Hash.values | select -property Values | where {$_.Values is $null}
doesn't pull back anything. Also tried:
$Hash.values | select -expandproperty Values | where {$_.Values is $null}
Any ideas?
thanks
Your best option is to cast the values to int when creating the hashtable:
$Hash = #{
Team1 = [int]$Team1.Count
Team2 = [int]$Team2.Count
Team3 = [int]$Team3.Count
}
If that's not possible for some reason you could go with an enumerator:
($Hash.GetEnumerator()) | ForEach-Object {
if ($_.Value -eq $null) { $Hash[$_.Name] = 0 }
}
or (as Mathias suggested) use the Keys property to the same end:
($Hash.Keys) | ForEach-Object {
if ($Hash[$_] -eq $null) { $Hash[$_] = 0 }
}
Note that either way you need to use a subexpression (or assign the enumerated objects/keys to a variable) otherwise you'll get an error because you're modifying a data structure while it's being enumerated.
What you'll want to do is collect the keys that refer to null values, and then populate those with 0s:
# Create and populate hashtable
$HashTable = #{
Team1 = 123
Team2 = $null
Team3 = 456
}
# Find keys of `$null` values
$nullKeys = $HashTable.Keys |Where-Object { $HashTable[$_] -eq $null }
# Populate appropriate indices with 0
$nullKeys |ForEach-Object { $HashTable[$_] = 0 }
I am storing data in a hashtable with multiple values like this:
$hash = #{}
$folders = dir (...) | where (...)
foreach ($folder in $folders) {
$num1 = (...)
$num2 = (...)
$hash.Add($folder.Name,#($num1,$num2))
}
So this is a hash with an array in its value part. The array always got two items. When finished the foreach part I want to show the data with Out-GridView like this:
$hash | select -Property #{Expression={$_.Name};Label="FolderName"},
#{Expression={$_.Name[0]};Label="num1"},
#{Expression={$_.Name[1]};Label="num2"} | Out-GridView
But as you can imagine, this is not working. How can I split the stored array in the value part of my hash into two new columns to show them in overall three columns in the GridView?
Should be something like Name, Value1, Value2 ...
And then multiple items which are stored in the hashtable as multiple rows.
Hashtables are not lists of objects with a Name and a Value property. That's just how PowerShell displays the data structure for your convenience. For processing a hashtable the way you tried you need an enumerator to produce such objects:
$hash.GetEnumerator() |
Select-Object #{n='FolderName';e={$_.Name}},
#{n='num1';e={$_.Value[0]}},
#{n='num2';e={$_.Value[1]}} |
Out-GridView
Or you can enumerate the keys of the hashtable, use them as the current objects in the pipeline, and look up the values by the respective key and index:
$hash.Keys |
Select-Object #{n='FolderName';e={$_}},
#{n='num1';e={$hash[$_][0]}},
#{n='num2';e={$hash[$_][1]}} |
Out-GridView
If you don't know the number of array elements beforehand you need an inner loop for processing the nested arrays, e.g. like this:
$hash.Keys | ForEach-Object {
$o = New-Object -Type PSObject -Property #{ 'FolderName' = $_ }
$a = $hash[$_]
for ($i = 1; $i -le $a.Count; $i++) {
$o | Add-Member -Type NoteProperty -Name "num$i" -Value $a[$i-1]
}
$o
} | Out-GridView
If you have a variable number of array elements, beware that PowerShell determines by the first object which properties will be displayed.
Get-EC2Instance |%{ $.RunningInstance } | select-object InstanceId,#{Name='Key'; Expression={$.Tag.Key} },#{Name='Value'; Expression={$_.Tag.Value} }
This command displays below output. Each InstanceID has multiple key and multiple values.
how do I rewrite the command to split each key string and value string so the output displays only one item, for example:
You can just pipe what you have into a ForEach loop, and then inside that do a For loop for each key/value pair like:
Get-EC2Instance |Select -ExpandProperty RunningInstance |
select-object InstanceId,#{Name='Key'; Expression={$.Tag.Key} },#{Name='Value'; Expression={$_.Tag.Value} } |
ForEach{
$CurInst = $_
For($i=0;$i -lt $CurInst.Key.Count;$i++){
New-Object PSObject -Prop#{
'InstanceId' = $CurInst.InstanceId
'Key' = $CurInst.Key[$i]
'Value' = $CurInst.Value[$i]
} #End object properties
} #End For Loop
} #End ForEach Loop
That should output like what you want.