Powershell Most efficient way to combine customobject - powershell

I'm parsing a webpage, but having difficulty combining into one variable.
I'm looking for the most efficient way to do so as well.
This is code I have so far. Any help is appreciated.
$WebResponse = Invoke-WebRequest -Uri "https://finviz.com/news.ashx"
$title = ($WebResponse.AllElements | Where {$_.class -match 'nn-tab-link'}).innertext
$time = ($WebResponse.AllElements | Where {$_.class -match 'nn-date'}).innertext
$link = ($WebResponse.AllElements | Where {$_.class -match 'nn-tab-link'}).href
$r = {
[PSCustomObject]#{
{Time(E/T)} = $time
Headline = $title
Link = $link
}
}
$R
Thanks

Use an index-based loop (which assumes that all three arrays have corresponding elements and the same element count):
$objects = foreach ($i in 0..($title.Count-1)) {
[pscustomobject] #{
'Time(E/T)' = $time[$i]
Headline = $title[$i]
Link = $link[$i]
}
}
Note how property name Time(E/T) is enclosed in '...' - a verbatim string - rather than in {...} - a script block; the latter only works accidentally, because script blocks stringify[1] to their verbatim content (without the { and }).
[1] When using the [pscustomobject] #{ ... } syntactic sugar, the keys of the hashtable (#{ ... }) are implicitly stringified, given that objects' property names are invariably strings.

Related

PS Object unescape character

I have small error when running my code. I assign a string to custom object but it's parsing the string by itself and throwing an error.
Code:
foreach ($item in $hrdblistofobjects) {
[string]$content = Get-Content -Path $item
[string]$content = $content.Replace("[", "").Replace("]", "")
#here is line 43 which is shown as error as well
foreach ($object in $listofitemsdb) {
$result = $content -match $object
$OurObject = [PSCustomObject]#{
ObjectName = $null
TestObjectName = $null
Result = $null
}
$OurObject.ObjectName = $item
$OurObject.TestObjectName = $object #here is line 52 which is other part of error
$OurObject.Result = $result
$Resultsdb += $OurObject
}
}
This code loads an item and checks if an object exists within an item. Basically if string part exists within a string part and then saves result to a variable. I am using this code for other objects and items but they don't have that \p part which I am assuming is the issue. I can't put $object into single quotes for obvious reasons (this was suggested on internet but in my case it's not possible). So is there any other option how to unescape \p? I tried $object.Replace("\PMS","\\PMS") but that did not work either (this was suggested somewhere too).
EDIT:
$Resultsdb = #(foreach ($item in $hrdblistofobjects) {
[string]$content = Get-Content -Path $item
[string]$content = $content.Replace("[", "").Replace("]", "")
foreach ($object in $listofitemsdb) {
[PSCustomObject]#{
ObjectName = $item
TestObjectName = $object
Result = $content -match $object
}
}
}
)
$Resultsdb is not defined as an array, hence you get that error when you try to add one object to another object when that doesn't implement the addition operator.
You shouldn't be appending to an array in a loop anyway. That will perform poorly, because with each iteration it creates a new array with the size increased by one, copies all elements from the existing array, puts the new item in the new free slot, and then replaces the original array with the new one.
A better approach is to just output your objects in the loop and collect the loop output in a variable:
$Resultsdb = foreach ($item in $hrdblistofobjects) {
...
foreach ($object in $listofitemsdb) {
[PSCustomObject]#{
ObjectName = $item
TestObjectName = $object
Result = $content -match $object
}
}
}
Run the loop in an array subexpression if you need to ensure that the result is an array, otherwise it will be empty or a single object when the loop returns less than two results.
$Resultsdb = #(foreach ($item in $hrdblistofobjects) {
...
})
Note that you need to suppress other output on the default output stream in the loop, so that it doesn't pollute your result.
I changed the match part to this and it's working fine $result = $content -match $object.Replace("\PMS","\\PMS").
Sorry for errors in posting. I will amend that.

What is '#{}' meaning in PowerShell

I have line of scripts for review here, I noticed variable declaration with a value:
function readConfig {
Param([string]$fileName)
$config = #{}
Get-Content $fileName | Where-Object {
$_ -like '*=*'
} | ForEach-Object {
$key, $value = $_ -split '\s*=\s*', 2
$config[$key] = $value
}
return $config
}
I wonder what #{} means in $config = #{}?
#{} in PowerShell defines a hashtable, a data structure for mapping unique keys to values (in other languages this data structure is called "dictionary" or "associative array").
#{} on its own defines an empty hashtable, that can then be filled with values, e.g. like this:
$h = #{}
$h['a'] = 'foo'
$h['b'] = 'bar'
Hashtables can also be defined with their content already present:
$h = #{
'a' = 'foo'
'b' = 'bar'
}
Note, however, that when you see similar notation in PowerShell output, e.g. like this:
abc: 23
def: #{"a"="foo";"b"="bar"}
that is usually not a hashtable, but the string representation of a custom object.
The meaning of the #{}
can be seen in diffrent ways.
If the #{} is empty, an empty hash table is defined.
But if there is something between the curly brackets it can be used in a contex of an splatting operation.
Hash Table
Splatting
I think there is no need in explaining what an hash table is.
Splatting is a method of passing a collection of parameter values to a command as unit.
$prints = #{
Name = "John Doe"
Age = 18
Haircolor = "Red"
}
Write-Host #prints
Hope it helps! BR
Edit:
Regarding the updated code from the questioner the answer is
It defines an empty hash table.
Be aware that Get-Content has its own parameters!
THE MOST IMPORTANT 1:
[-Raw]

Concatenating a variable and a string literal without a space to an array using PowerShell

I'm trying add to a variable and a string in an array dynamically but i'm not getting expected output.
(1) I'm getting env name
(2) Concatinating the string and variable in an array
Code is as follows.
$env = $env:COMPUTERNAME.Substring(0,2)
$servers = { $env+"server1.test.com",$env+"server2.test.com" }
$serverCount = $servers -split(",") | measure | % { $_.Count }
For ($i=0; $i -lt $serverCount; $i++)
{
$ServerName = $servers -split(',') -replace '\[\d+\]'
$server = $ServerName[$i]
Write-Host $server
}
output i'm getting as
$env+"server1.test.com"
$env+"server2.test.com"
Values are not getting concatenated properly and variable value is not getting displayed. Any help.
$servers = { $env+"server1.test.com",$env+"server2.test.com" }
This is a scriptblock, not an array. {} is like a function, you have to run it for it to do anything (such as evaluating $env).
When you force it into a string using -split(",") what you get is text representation of the source code in the scriptblock, including the variable names.
As #Olaf comments, the right way to create an array of names is
$servers = ($env + "server1.test.com"), ($env + "server2.test.com")
This might be how I'd write it:
$env = $env:COMPUTERNAME.Substring(0,2)
"server1.test.com", "server2.test.com" | foreach-object {
"$env$_" -replace '\d+'
}

How can I pass dynamic parameters to powershell script and iterate over the list?

I want to create a powershell script that accepts dynamic parameters and I also want to iterate through them.
eg:
I call the powershell script in the following manner.
ParametersTest.ps1 -param1 value1 -param2 value2 -param3 value3
And I should be able to access my params inside the script as follows:
for($key in DynamicParams) {
$paramValue = DynamicParams[$key];
}
Is there anyway to do this in powershell? Thanks in advance.
There is nothing built-in like that (essentially you're asking for PowerShell parameter parsing in the absence of any definition of those parameters). You can emulate it, though. With $args you can get at all arguments of the function as an array. You can then iterate that and decompose it into names and values:
$DynamicParams = #{}
switch -Regex ($args) {
'^-' {
# Parameter name
if ($name) {
$DynamicParams[$name] = $value
$name = $value = $null
}
$name = $_ -replace '^-'
}
'^[^-]' {
# Value
$value = $_
}
}
if ($name) {
$DynamicParams[$name] = $value
$name = $value = $null
}
To iterate over dynamic parameters you can either do something like you wrote
foreach ($key in $DynamicParams.Keys) {
$value = $DynamicParams[$key]
}
(note the foreach, not for, the latter of which cannot work like you wrote it) or just iterate normally over the hash table:
$DynamicParams.GetEnumerator() | ForEach-Object {
$name = $_.Key
$value = $_.Value
}

Compare objects based on subset of properties

Say I have 2 powershell hashtables one big and one small and, for a specific purpose I want to say they are equal if for the keys in the small one, the keys on the big hastable are the same.
Also I don't know the names of the keys in advance. I can use the following function that uses Invoke-Expression but I am looking for nicer solutions, that don't rely on this.
Function Compare-Subset {
Param(
[hashtable] $big,
[hashtable] $small
)
$keys = $small.keys
Foreach($k in $keys) {
$expression = '$val = $big.' + "$k" + ' -eq ' + '$small.' + "$k"
Invoke-Expression $expression
If(-not $val) {return $False}
}
return $True
}
$big = #{name='Jon'; car='Honda'; age='30'}
$small = #{name = 'Jon'; car='Honda'}
Compare-Subset $big $small
A simple $true/$false can easily be gotten. This will return $true if there are no differences:
[string]::IsNullOrWhiteSpace($($small|Select -Expand Keys|Where{$Small[$_] -ne $big[$_]}))
It checks for all keys in $small to see if the value of that key in $small is the same of the value for that key in $big. It will only output any values that are different. It's wrapped in a IsNullOrWhitespace() method from the [String] type, so if any differences are found it returns false. If you want to list differences just remove that method.
This could be the start of something. Not sure what output you are looking for but this will output the differences between the two groups. Using the same sample data that you provided:
$results = Compare-Object ($big.GetEnumerator() | % { $_.Name }) ($small.GetEnumerator() | % { $_.Name })
$results | ForEach-Object{
$key = $_.InputObject
Switch($_.SideIndicator){
"<="{"Only reference object has the key: '$key'"}
"=>"{"Only difference object has the key: '$key'"}
}
}
In primetime you would want something different but just to show you the above would yield the following output:
Only reference object has the key: 'age'