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Diffstat (limited to 'powershell.html.markdown')
| -rw-r--r-- | powershell.html.markdown | 144 |
1 files changed, 129 insertions, 15 deletions
diff --git a/powershell.html.markdown b/powershell.html.markdown index be802916..6f38c45c 100644 --- a/powershell.html.markdown +++ b/powershell.html.markdown @@ -6,10 +6,14 @@ contributors: filename: LearnPowershell.ps1 --- -PowerShell is the Windows scripting language and configuration management framework from Microsoft built on the .NET Framework. Windows 7 and up ship with PowerShell. -Nearly all examples below can be a part of a shell script or executed directly in the shell. +PowerShell is the Windows scripting language and configuration management +framework from Microsoft built on the .NET Framework. Windows 7 and up ship +with PowerShell. +Nearly all examples below can be a part of a shell script or executed directly +in the shell. -A key difference with Bash is that it is mostly objects that you manipulate rather than plain text. +A key difference with Bash is that it is mostly objects that you manipulate +rather than plain text. [Read more here.](https://technet.microsoft.com/en-us/library/bb978526.aspx) @@ -38,6 +42,10 @@ Get-Alias -Definition Get-Process Get-Help ps | less # alias: help ps | Get-Member # alias: gm + +Show-Command Get-EventLog # Display GUI to fill in the parameters + +Update-Help # Run as admin ``` The tutorial starts here: @@ -49,20 +57,21 @@ echo Hello world! # echo is an alias for Write-Output (=cmdlet) # Most cmdlets and functions follow the Verb-Noun naming convention -# Each command starts on a new line, or after semicolon: +# Each command starts on a new line, or after a semicolon: echo 'This is the first line'; echo 'This is the second line' # Declaring a variable looks like this: $aString="Some string" # Or like this: -$aNumber = 5 +$aNumber = 5 -as [double] $aList = 1,2,3,4,5 +$aString = $aList -join '--' # yes, -split exists also $aHashtable = @{name1='val1'; name2='val2'} # Using variables: echo $aString echo "Interpolation: $aString" -echo "`$aString has length of $($aString.length)" +echo "`$aString has length of $($aString.Length)" echo '$aString' echo @" This is a Here-String @@ -84,15 +93,14 @@ echo "Full path of current script directory: $PSScriptRoot" echo 'Full path of current script: ' + $MyInvocation.MyCommand.Path echo "FUll path of current directory: $Pwd" echo "Bound arguments in a function, script or code block: $PSBoundParameters" -echo "Unbound arguments: $($Args -join ', ')." ######################## MOVE THIS TO FUNCTIONS +echo "Unbound arguments: $($Args -join ', ')." # More builtins: `help about_Automatic_Variables` -# Reading a value from input: -$Name = Read-Host "What's your name?" -echo "Hello, $Name!" -[int]$Age = Read-Host "What's your age?" +# Inline another file (dot operator) +. .\otherScriptName.ps1 -# Control Flow + +### Control Flow # We have the usual if structure: if ($Age -is [string]) { echo 'But.. $Age cannot be a string!' @@ -127,7 +135,14 @@ foreach ($var in 'val1','val2','val3') { echo $var } # do {} while () # do {} until () +# Exception handling +try {} catch {} finally {} +try {} catch [System.NullReferenceException] { + echo $_.Exception | Format-List -Force +} + +### Providers # List files and directories in the current directory ls # or `dir` cd ~ # goto home @@ -140,6 +155,8 @@ cd HKCU: # go to the HKEY_CURRENT_USER registry hive # Get all providers in your session Get-PSProvider + +### Pipeline # Cmdlets have parameters that control their execution: Get-ChildItem -Filter *.txt -Name # Get just the name of all txt files # Only need to type as much of a parameter name until it is no longer ambiguous @@ -171,10 +188,96 @@ Get-EventLog Application -After (Get-Date).AddHours(-2) | Format-List # Get-Process as a table with three columns # The third column is the value of the VM property in MB and 2 decimal places -# Computed columns can be written more succinctly as: `@{n='lbl';e={$_}` -ps | Format-Table ID,Name,@{name='VM(MB)';expression={'{0:n2}' -f ($_.VM / 1MB)}} -autoSize +# Computed columns can be written more verbose as: +# `@{name='lbl';expression={$_}` +ps | Format-Table ID,Name,@{n='VM(MB)';e={'{0:n2}' -f ($_.VM / 1MB)}} -autoSize + + +### Functions +# The [string] attribute is optional. +function foo([string]$name) { + echo "Hey $name, have a function" +} + +# Calling your function +foo "Say my name" + +# Functions with named parameters, parameter attributes, parsable documention +<# +.SYNOPSIS +Setup a new website +.DESCRIPTION +Creates everything your new website needs for much win +.PARAMETER siteName +The name for the new website +.EXAMPLE +New-Website -Name FancySite -Po 5000 +New-Website SiteWithDefaultPort +New-Website siteName 2000 # ERROR! Port argument could not be validated +('name1','name2') | New-Website -Verbose +#> +function New-Website() { + [CmdletBinding()] + param ( + [Parameter(ValueFromPipeline=$true, Mandatory=$true)] + [Alias('name')] + [string]$siteName, + [ValidateSet(3000,5000,8000)] + [int]$port = 3000 + ) + BEGIN { Write-Verbose 'Creating new website(s)' } + PROCESS { echo "name: $siteName, port: $port" } + END { Write-Verbose 'Website(s) created' } +} + +### It's all .NET +# A PS string is in fact a .NET System.String +# All .NET methods and properties are thus available +'string'.ToUpper().Replace('G', 'ggg') +# Or more powershellish +'string'.ToUpper() -replace 'G', 'ggg' +# Unsure how that .NET method is called again? +'string' | gm + +# Syntax for calling static .NET methods +[System.Reflection.Assembly]::LoadWithPartialName('Microsoft.VisualBasic') + +# Note that .NET functions MUST be called with parentheses +# while PS functions CANNOT be called with parentheses +$writer = New-Object System.IO.StreamWriter($path, $true) +$writer.Write([Environment]::NewLine) +$write.Dispose() + +### IO +# Reading a value from input: +$Name = Read-Host "What's your name?" +echo "Hello, $Name!" +[int]$Age = Read-Host "What's your age?" + +# Test-Path, Split-Path, Join-Path, Resolve-Path +# Get-Content filename # returns a string[] +# Set-Content, Add-Content, Clear-Content +Get-Command ConvertTo-*,ConvertFrom-* + + +### Useful stuff +# Refresh your PATH +$env:PATH = [System.Environment]::GetEnvironmentVariable("Path", "Machine") + + ";" + [System.Environment]::GetEnvironmentVariable("Path", "User") +# Find Python in path +$env:PATH.Split(";") | Where-Object { $_ -like "*python*"} + +# Change working directory without having to remember previous path +Push-Location c:\temp # change working directory to c:\temp +Pop-Location # change back to previous working directory + +# Unblock a directory after download +Get-ChildItem -Recurse | Unblock-File + +# Open Windows Explorer in working directory +ii . ``` @@ -187,4 +290,15 @@ if (-not (Test-Path $Profile)) { notepad $Profile } # More info: `help about_profiles` -```
\ No newline at end of file +``` + +Interesting Projects +* [Channel9](https://channel9.msdn.com/Search?term=powershell%20pipeline#ch9Search&lang-en=en) PowerShell videos +* [PSake](https://github.com/psake/psake) Build automation tool +* [Pester](https://github.com/pester/Pester) BDD Testing Framework + +Not covered +* WMI: Windows Management Intrumentation (Get-CimInstance) +* Multitasking: Start-Job -scriptBlock {...}, +* Code Signing +* Remoting (Enter-PSSession/Exit-PSSession; Invoke-Command)
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