Powershell 101

powershell-101.ps1

#requires -version 4

get-childitem variable:
get-module -ListAvailable
get-module psake

<#

Powershell 101

Just a dumping ground for some techniques.

TODO: I need to get some best practices / coding standards & boiler plate sorted.

#>

## Version

$psversiontable



# or (Less good)

if ($false)
{

$hostVersionInfo = (get-host).Version.Major
if ( $hostVersionInfo -eq "2" )
{
  # For PowerShell v2
  write "We appear to be using PS version $hostVersionInfo... That's okay, but this script processes faster with PS v3!"
  write ""
  $containers = Get-ChildItem -path $MoLoPath\$CurrentParent -recurse | ? {$_.psIscontainer -eq $true}
}
elseif ( $hostVersionInfo -eq "3" )
{
  # For PowerShell v3
  write "We appear to be using PS version $hostVersionInfo... Good!"
  write ""
  $containers = Get-ChildItem -Directory -path $MoLoPath -recurse
}
else
{
  write-host "Unknown/unapproved version of PowerShell. Exiting!"
  exit
}
}


## Alias's

Get-Alias

<#
% and ? are the only flow control ones defined.


% ForEach-Object
? Where


  `...der | ? { $_ } | % { $syncExclusi….
`


NOTE: ForEach (item In collection) {ScriptBlock} is DIFFERENT to foreach-object
TODO: I must understand this.

#>

Get-Process | ForEach-Object {Write-Host $_.name -foregroundcolor cyan}

Get-Process | % {Write-Host $_.name -foregroundcolor cyan}

## Grid View

For example:

```
Get-Command -PSSnapin Microsoft.PowerShell.Utility |sort-object PSSnapIn, noun | get-help -full | Out-GridView
```
## Arrays

$animal = @()

$animal

$animal = "Cat", "Dog"

$animal

$animal.count

$animal += "Hampster"

$animal
$animal[0]
$animal[$animal.count-1]

$animal -ne "Cat"
$animal -like '*a*'

[array]::Reverse($animal)


$animal | % { Write-Output ">>" $_}

$animal.GetType()

"$animal" # So all on one line


## Hash tables

$table = @{}
$table.count


$table.GetType()


# functions
#
# Always use the attribute [cmdletbindings()], even if there are no paramaters
#
# If you ned vriable no of parameters then use `$args` (Not sure if you can use cmdletbindings() in that
# case
#


function my-function

{

 [cmdletbinding()]

 Param()

 Write-Verbose "Hi Rik"

}


my-function 1291212



function ex_01
{
#(param)

  Write-Output "Fn 01"
}

ex_01

function ConvertTo-html
{
    <#

    get-alias | convertto-html > .\aliases.htm
    Invoke-Item .\aliases.htm
    get-eventlog -logname "Windows PowerShell" | convertto-html > pslog.htm
    Invoke-Item .\pslog.htm
    get-process | convertto-html -property Name, Path, Company -title "Process Information" > proc.htm; ii proc.htm

    get-service A* | ConvertTo-Html -title "Windows Services: Server01" `
      -body (get-date)     `
      -pre "<P>Generated by Corporate IT</P>" `
      -post "For details, contact Corporate IT." > services.htm;        ii services.htm


    Write-output $variable
#>


}


##################
<#
Create a pipe-able function
#>

function sqrt {
    param(
        [Parameter(ValueFromPipeline)]
        $p
    )

    Process{[Math]::Sqrt($p)}
}

<# Then #>

sqrt 25

25 | sqrt

6..10 | sqrt


#############

function my-function-with-no-parameters

{

 [cmdletbinding()]

 Param()

 Write-Output "Hello from my-function-with-no-parameters"

}

my-function-with-no-parameters

my-function-with-no-parameters 1291212


if (([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator"))
{Write-Output 'Running as Administrator!'}
else
{Write-Output 'Running Limited!'}