Category: PowerShell

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Big List of Cheat sheets and References

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Table of Contents: Emoji Charts Table

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gist/vexx32/PowershellLoopBehavior.md

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Categories
PowerShell Quick Tips

Creating a Discord Webhook in a few lines of PowerShell

Discord Web Hooks are easier than you’d think. It uses a regular `HTTP` web request .

Step1: Creating your webhook url

Go to: Server Settings -> Integrations -> View Webhooks
Then click create webhook.

Choose a name, the channel, then copy webhook url

Step2: Invoke-RestMethod

$webhookUri = 'https://discord.com/api/YourWebhookUrlHere'

$Body = @{
  'username' = 'Nomad'
  'content' = 'https://memory-alpha.fandom.com/wiki/Nomad'
}
Invoke-RestMethod -Uri $webhookUri -Method 'post' -Body $Body

Success!

Docs

There are optional webhook arguments to customize the output: https://discord.com/developers/docs/resources/webhook#execute-webhook

Comparison with curl

I tried making curl easier to read by splitting content, and pipe so that you don’t have to manually escape Json

$Json = @{ 'username' = 'Nomad'; 'content' = 'https://memory-alpha.fandom.com/wiki/Nomad' } | ConvertTo-Json -Compress

$Json | curl -X POST -H 'Content-Type: application/json' -d '@-' $webhookUri

Categories
Command Line PowerShell Quick Tips References And Cheat Sheets

Easy way to cache results on the Command Line | Power Shell Tip

Sometimes you’ll need to run a command with the same input with different logic.
This can be a hassle using a slow command like Get-ADUser or Get-ChildItem on a lot of files like ~ (Home) with -Depth / -Recurse

ls ~ -Depth 4 | Format-Table Name

PowerShell 7.0+

Powershell 7 added the Ternary Operator, and several operators for handling $null values.

All of these examples will only run Get-ChildItem the first time. Any future calls are cached.

Null-Coalesce ??= Assignment Operator

This is my favorite on the Command line. The RHS (Right Hand Side) skips evaluation if the left side is not $null

$AllFiles ??= ls ~ -Depth 4

Using the Null-Coalesce ?? Operator

$AllFiles = $AllFiles ?? ( ls ~ -Depth 4  )

Ternary Operator ? whenTrue : WhenFalse

$allFiles = $allFiles ? $allFiles : ( ls ~ -Depth 4 )

Windows PowerShell and Powershell < 7

Windows Powershell can achieve the same effect with an if statement

if(! $AllFiles) { $AllFiles = ls ~ -Depth 4 }
Categories
PowerShell Quick Tips What's New

PowerShell : Prefixing lines with the Pipe operator |

There’s a lot of ways to use line continuations in Windows Powershell without backticks . Powershell added a new one, the | pipe operator. It’s cleaner to read, and makes it easier to insert, delete, or toggle comments on the console.

Now you can write:

# Powershell
ls | sort Length
| Select -First 10
| ft Name, Length

Instead of piping on line endings

# Windows Powershell
ls | sort Length |
Select -First 10 |
ft Name, Length

# or
ls | sort Length | Select -First 10 | ft Name, Length
Categories
Formatting PowerShell Snippets

Reusable Calculated Properties in PowerShell

The function Label is from the module: github.com/Ninmonkey.Console

$basePath = 'C:\Program Files'
$calcProp = @{}
$calcProp.FileSize = @{
    n         = 'Size'
    e         = { $_.Length | Format-FileSize }
    Alignment = 'right'
}
# relative path defaults to relative your current location, so I override it
$calcProp.RelativePath = @{
    n = 'RelativePath'
    e = {
        Push-Location $baseBath
        $_.FullName | Resolve-Path -Relative
        Pop-Location
    }
}
$calcProp.ColorizedName = @{
    n = 'ColorName'
    e = {
        $Color = ($_ | Test-IsDirectory) ? 'blue' : 'green'
        Label $_.Name -fg $Color -Separator ''
    }
}

$DefaultPropList = 'Name', $calcProp.ColorizedName, $calcProp.RelativePath

Label 'basePath' $basePath

$files = Get-ChildItem $basePath -Depth 2
$files | Format-Table Name, Length, $calcProp.FileSize, $calcProp.RelativePath

$files | Format-Table  $calcProp.FileSize, $calcProp.ColorizedName

# Using pre-declared property lists, which may include scriptblocks like $calcProp.FileSize
$files | Format-Table -Property $DefaultPropList

Categories
PowerShell References And Cheat Sheets

Learning PowerShell

Getting started with PowerShell

Main

Grammar

Important Topics, Language quirks

For( ;; ) vs ForEach vs ForEach-Object

It’s first argument is a ScriptBlock so it appears like a control loop.

Notice return verses break in ForEach-Object . Remember that the { ... stuff ... } in this case is an anonymous function , not a language control statement
It is a parameter to the ForEach-Object . When not specified, it’s the -Process Parameter

Flow Control with language Keywords

Attributes for validation

Best Practices

Naming

Categories
PowerShell Quick Tips Regex

Using Case-Sensitive Regular expressions in PowerShell – Tips

Find-Member using a case-insensitive Regex

Say you want to find functions that uses parameters named like:
-AsString, -AsHashTable, or -AsByteStream

Using Find-Member makes it easy.

> Find-Member -Name 'As*'

That’s close, but I want it to start with a capital letter, to skip matches like:
Assembly or Asin

Converting Like to a Regex

The -like pattern As* is the same as the regex ^As
To start with a capital letter you could use: ^As[A-Z]

Disabling Case-Sensitive matches

Because PowerShell defaults to case-insensitive matches
You need to remove the i insensitive flag using the syntax (?-i)

Solution

> Find-Member -Name '(?-i)^As[A-Z]' -RegularExpression

The final pattern is (?-i)^As[A-Z]
Making it case-sensitive narrowed down the matches from 113 to 43 !

See More