summaryrefslogtreecommitdiffhomepage
path: root/powershell.html.markdown
diff options
context:
space:
mode:
Diffstat (limited to 'powershell.html.markdown')
-rw-r--r--powershell.html.markdown320
1 files changed, 320 insertions, 0 deletions
diff --git a/powershell.html.markdown b/powershell.html.markdown
new file mode 100644
index 00000000..4bc1ab39
--- /dev/null
+++ b/powershell.html.markdown
@@ -0,0 +1,320 @@
+---
+category: tool
+tool: powershell
+contributors:
+ - ["Wouter Van Schandevijl", "https://github.com/laoujin"]
+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.
+
+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)
+
+If you are uncertain about your environment:
+```
+Get-ExecutionPolicy -List
+Set-ExecutionPolicy AllSigned
+# Execution policies include:
+# - Restricted: Scripts won't run.
+# - RemoteSigned: Downloaded scripts run only if signed by a trusted publisher.
+# - AllSigned: Scripts need to be signed by a trusted publisher.
+# - Unrestricted: Run all scripts.
+help about_Execution_Policies # for more info
+
+# Current PowerShell version:
+$PSVersionTable
+```
+
+Getting help:
+```
+# Find commands
+Get-Command about_* # alias: gcm
+Get-Command -Verb Add
+Get-Alias ps
+Get-Alias -Definition Get-Process
+
+Get-Help ps | less # alias: help
+ps | Get-Member # alias: gm
+
+Show-Command Get-EventLog # Display GUI to fill in the parameters
+
+Update-Help # Run as admin
+```
+
+The tutorial starts here:
+```
+# As you already figured, comments start with #
+
+# Simple hello world example:
+echo Hello world!
+# echo is an alias for Write-Output (=cmdlet)
+# Most cmdlets and functions follow the Verb-Noun naming convention
+
+# Each command starts on a new line, or after a semicolon:
+echo 'This is the first line'; echo 'This is the second line'
+
+# Declaring a variable looks like this:
+$aString="Some string"
+# Or like this:
+$aNumber = 5 -as [double]
+$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 '$aString'
+echo @"
+This is a Here-String
+$aString
+"@
+# Note that ' (single quote) won't expand the variables!
+# Here-Strings also work with single quote
+
+# Builtin variables:
+# There are some useful builtin variables, like
+echo "Booleans: $TRUE and $FALSE"
+echo "Empty value: $NULL"
+echo "Last program's return value: $?"
+echo "Exit code of last run Windows-based program: $LastExitCode"
+echo "The last token in the last line received by the session: $$"
+echo "The first token: $^"
+echo "Script's PID: $PID"
+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 ', ')."
+# More builtins: `help about_Automatic_Variables`
+
+# Inline another file (dot operator)
+. .\otherScriptName.ps1
+
+
+### Control Flow
+# We have the usual if structure:
+if ($Age -is [string]) {
+ echo 'But.. $Age cannot be a string!'
+} elseif ($Age -lt 12 -and $Age -gt 0) {
+ echo 'Child (Less than 12. Greater than 0)'
+} else {
+ echo 'Adult'
+}
+
+# Switch statements are more powerfull compared to most languages
+$val = "20"
+switch($val) {
+ { $_ -eq 42 } { "The answer equals 42"; break }
+ '20' { "Exactly 20"; break }
+ { $_ -like 's*' } { "Case insensitive"; break }
+ { $_ -clike 's*'} { "clike, ceq, cne for case sensitive"; break }
+ { $_ -notmatch '^.*$'} { "Regex matching. cnotmatch, cnotlike, ..."; break }
+ { 'x' -contains 'x'} { "FALSE! -contains is for lists!"; break }
+ default { "Others" }
+}
+
+# The classic for
+for($i = 1; $i -le 10; $i++) {
+ "Loop number $i"
+}
+# Or shorter
+1..10 | % { "Loop number $_" }
+
+# PowerShell also offers
+foreach ($var in 'val1','val2','val3') { echo $var }
+# while () {}
+# do {} while ()
+# do {} until ()
+
+# Exception handling
+try {} catch {} finally {}
+try {} catch [System.NullReferenceException] {
+ echo $_.Exception | Format-List -Force
+}
+
+
+### Providers
+# List files and directories in the current directory
+ls # or `dir`
+cd ~ # goto home
+
+Get-Alias ls # -> Get-ChildItem
+# Uh!? These cmdlets have generic names because unlike other scripting
+# languages, PowerShell does not only operate in the current directory.
+cd HKCU: # go to the HKEY_CURRENT_USER registry hive
+
+# Get all providers in your session
+Get-PSProvider
+
+
+### Pipeline
+# Cmdlets have parameters that control their execution:
+Get-ChildItem -Filter *.txt -Name # Get just the name of all txt files
+# Only need to type as much of a parameter name until it is no longer ambiguous
+ls -fi *.txt -n # -f is not possible because -Force also exists
+# Use `Get-Help Get-ChildItem -Full` for a complete overview
+
+# Results of the previous cmdlet can be passed to the next as input.
+# `$_` is the current object in the pipeline object.
+ls | Where-Object { $_.Name -match 'c' } | Export-CSV export.txt
+ls | ? { $_.Name -match 'c' } | ConvertTo-HTML | Out-File export.html
+
+# If you get confused in the pipeline use `Get-Member` for an overview
+# of the available methods and properties of the pipelined objects:
+ls | Get-Member
+Get-Date | gm
+
+# ` is the line continuation character. Or end the line with a |
+Get-Process | Sort-Object ID -Descending | Select-Object -First 10 Name,ID,VM `
+ | Stop-Process -WhatIf
+
+Get-EventLog Application -After (Get-Date).AddHours(-2) | Format-List
+
+# Use % as a shorthand for ForEach-Object
+(a,b,c) | ForEach-Object `
+ -Begin { "Starting"; $counter = 0 } `
+ -Process { "Processing $_"; $counter++ } `
+ -End { "Finishing: $counter" }
+
+# Get-Process as a table with three columns
+# The third column is the value of the VM property in MB and 2 decimal places
+# Computed columns can be written more verbose as:
+# `@{name='lbl';expression={$_}`
+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 { $_ -like "*python*"}
+
+# Change working directory without having to remember previous path
+Push-Location c:\temp # change working directory to c:\temp
+Pop-Location # change back to previous working directory
+
+# Unblock a directory after download
+Get-ChildItem -Recurse | Unblock-File
+
+# Open Windows Explorer in working directory
+ii .
+
+# Any key to exit
+$host.UI.RawUI.ReadKey()
+return
+
+# Create a shortcut
+$WshShell = New-Object -comObject WScript.Shell
+$Shortcut = $WshShell.CreateShortcut($link)
+$Shortcut.TargetPath = $file
+$Shortcut.WorkingDirectory = Split-Path $file
+$Shortcut.Save()
+```
+
+
+Configuring your shell
+```
+# $Profile is the full path for your `Microsoft.PowerShell_profile.ps1`
+# All code there will be executed when the PS session starts
+if (-not (Test-Path $Profile)) {
+ New-Item -Type file -Path $Profile -Force
+ notepad $Profile
+}
+# More info: `help about_profiles`
+# For a more usefull shell, be sure to check the project PSReadLine below
+```
+
+Interesting Projects
+* [Channel9](https://channel9.msdn.com/Search?term=powershell%20pipeline#ch9Search&lang-en=en) PowerShell tutorials
+* [PSGet](https://github.com/psget/psget) NuGet for PowerShell
+* [PSReadLine](https://github.com/lzybkr/PSReadLine/) A bash inspired readline implementation for PowerShell (So good that it now ships with Windows10 by default!)
+* [Posh-Git](https://github.com/dahlbyk/posh-git/) Fancy Git Prompt (Recommended!)
+* [PSake](https://github.com/psake/psake) Build automation tool
+* [Pester](https://github.com/pester/Pester) BDD Testing Framework
+* [Jump-Location](https://github.com/tkellogg/Jump-Location) Powershell `cd` that reads your mind
+* [PowerShell Community Extensions](http://pscx.codeplex.com/) (Dead)
+
+Not covered
+* WMI: Windows Management Intrumentation (Get-CimInstance)
+* Multitasking: Start-Job -scriptBlock {...},
+* Code Signing
+* Remoting (Enter-PSSession/Exit-PSSession; Invoke-Command)