Create Object
# example 1
$var = New-Object System.DateTime
# example 2
$newObject = [PSCustomObject]@{
ComputerName = 'Server1'
Role = 'Interface'
Environment = 'Production'
}
Split variable
$intput = "foo.baz,bar"
$part = $input.Split(".")
$fooVar = $part[0]
$bazVar = $part[1]
$barVar = $part[2]
# simply do this
$foo, $baz, $bar = $input.Split(".")
# whatif number of variables is less than splits.
$foo, $sec = $input.Split(".")
# $foo == foo, $sec = ["baz", "bar"]
Scope(global and local)
$foo = "global"
function myFunc {
$foo = "local"
Write-Host $global:foo # global
Write-Host $local:foo # local
Write-Host $foo # local
}
# call function
myFunc
Write-Host $local:foo # global
Write-Host $foo # global
Remove Variable
$var = "something in here"
# remove it
Remove-Variable -Name var
# or
rv var
Operators
Comparision Operators
-eq ==
-ne !=
-gt >
-ge >=
-lt <
-le <=
# example
# 5 -eq 5
#-----------------------------
# String comparison operators
"myString" -like "*String"
"myString" -nolike "Other*"
"myString" -match '^String$'
"myString" -nomatch '^Other$'
#-----------------------------
# Collection comparison operators
"abc", "def" -contains "def" # return true
"abc", "def" -notcontains "123" # return true
"def" -in "abc", "def" # return true
"123" -notin "abc", "def" # return true
Arithmetic Operators
+
-
-1 # set negative value
*
/
%
# Bitwise
100 -shl 2 # Bitwise Shift-left
100 -shr 1 # Bitwise Shift-right
#------------------------------
# Assignment Operators
$var = 1
$var += 1
...
$var++
$var--
Mixing operand types
# For Addition
"4" + 2 # 42
4 + "2" # 6
1,2,3 + "Hello" # 1,2,3,"Hello"
"Hello" + 1,2,3 # "Hello1 2 3"
# For Multiplication
"3" * 2 # "33"
2 * "3" # 6
1,2,3 * 2 # 1,2,3,1,2,3
2 * 1,2,3 # error
Read Input
$a = Read-Host "Enter a number:"
# assigned value into $a
Logical Operator
-and
-or
-xor # exclusive or
-not
! # not
Replace Operator
"The rain in Seattle." -replace 'rain' 'hail' # return "The hail in Seattle."
split and join
"A B C" -split " " # Return an array string
"E", "F", "G" -join ":" # Return a single string, E,F,G
Where
Where-Object
where
?
Select
$dir = dir "C:\myDir"
$dir | select Name, FullName, Attributes
Foreach
shorthand syntax == %
$Numbers = ForEach ($Number in 1..20) {
$Number
}
(1..10).ForEach{$_ * $_}
# output
1
4
9
16
25
...
Break Labels
$i = 0
:mainLoop While($i -lt 15) {
$j = 0
While($j -lt 15) {
if($i -gt 10) {
break mainLoop
}
$j++
}
$i++
}
while application
Start-Process notepad.exe
while(Get-Process notepad -ErrorAction SilentlyContinue) {
Start-Sleep -Milliseconds 500
}
switch
switch($val){
'First condition' {First action}
'Second condition' {Second action}
Default {}
}
Case Sensitive
switch -CaseSensitive ('Condition'){
'condition' {First action}
'Condition' {Second action}
Default {}
}
# output: Second action
Wildcard
switch -Wildcard ('Condition') {
'Condition' {first}
'Condit*' {second}
'C[aeo]ndit[f-l]on' {third}
'C?ndition' {fourth}
'Test*' {fifth}
Default {}
}
File
# input.txt
# condition
# test
switch -file input.txt
{
'condition' {First}
'test' {Second}
'fail' {Third}
Default {}
}
# output
# First
# Second
Special characters
`0 # NUll
`a # Alert/Beep
`b # Backspace
`f # Form feed (used for printer output)
`n # New line
`r # Carriage return
`t # Horizontal tab
`v # Vertical tab (used for printer output)
`# # Comment-operator
`$ # Variable operator
`` # Escape character
`' # Single quote
`" # Double quote
Create new object
$newArr = @()
$newArr += New-Object -TypeName PSObject -Property @{
Name = $env:username
ID = 12
Address = $null
}
Function with Parameters
function write-greeting {
param(
[Parameter(Mandatory, Position=0)]
[String]$name
[Parameter(Mandatory, Position=1)]
[Int]$age
)
"Hello $name, you are $age years old"
}
or simple function
function write-greeting($name, $age) {
"Hello $name, you are $age years old"
}
# The order of the parameters on the invocation
# is matched to the order of the declaration in the function header(by default),
# or can be specified using the Position Parameter Attribute.
$greeting = Write-Greeting "Jim" 82
# Alternatively
$greeting = Write-Greeting -name "Bob" -age 82
cmdletbinding - function will behave like a cmdlet
function Verb-Noun
{
[Cmdletbinding(DefaultParameterSetName='Parameter Set 1',
SupportsShouldProcess=$true,
PositionalBinding=$false,
HelpUri = 'http://www.microsoft.com/',
ConfirmImpact='Medium'
)]
...
}
Mandatory Parameters
function Get-Greeting {
param
(
[Parameter(Mandatory=$true)]$name
)
"Hello World $name"
}
# the command line will prompt for the value
$greeting = Get-Greeting
ValidateSet
Need to restrict the possible values that a parameter can accept.
param(
[ValidateSet('red', 'green', 'blue', IgnoreCase)]
[string]$Color
)
ValidateRange
param(
[ValidateRange(0,120)]
[Int]$Age
)
ValidatePattern
param(
[ValidatePattern("\w{4-6}\d{2}")]
[string]$UserName
)
Validatelength
param(
[ValidateLength(0,15)]
[String]$PhoneNumber
)
ValidateCount
This method of parameter validation tests the amount of arguments passed in, for example, an array of strings.
param(
[ValidateCount(1,5)]
[String[]]$ComputerName
)
ValidateScript
Finally, the ValidateScript method is extraordinarily flexible, taking a scriptblock and evaluating it using $_ to represent the passed argument.
It then passes the argument if the result is $true (including any output as valid).
This can be used to test that a file exists:
param(
[ValidateScript({Test-Path $_})]
[IO.FileInfo]$Path
)
param(
[ValidateScript({Get-ADUser $_})]
[String]$UserName
)
listing available constructors for a class
You can list available constructors by calling the static new-method without parethese.
[DateTime]::new
OverloadDefinitions
-------------------
datetime new(long ticks)
datetime new(long ticks, System.DateTimeKind kind)
datetime new(int year, int month, int day)
datetime new(int year, int month, int day, System.Globalization.Calendar
calendar)
datetime new(int year, int month, int day, int hour, int minute, int second)
datetime new(int year, int month, int day, int hour, int minute, int second,
System.DateTimeKind kind)
datetime new(int year, int month, int day, int hour, int minute, int second,
System.Globalization.Calendar calendar)
datetime new(int year, int month, int day, int hour, int minute, int second,
int millisecond)
datetime new(int year, int month, int day, int hour, int minute, int second,
int millisecond, System.DateTimeKind kind)
datetime new(int year, int month, int day, int hour, int minute, int second,
int millisecond, System.Globalization.Calendar calendar)
datetime new(int year, int month, int day, int hour, int minute, int second,
int millisecond, System.Globalization.Calendar calendar, System.DateTimeKind
kind)
Methods and properties
class Person {
[string] $FirstName
[string] $LastName
[string] Greeting() {
return "Greetings, {0} {1}" -f $this.FirstName, $this.LastName
}
}
$x = [Person]::new()
$x.FirstName = "Jane"
$x.LastName = "Doe"
$greeting = $x.Greeting() # output: "Greetings, Jane Doe!"
Overloading
class Person {
[string] $name
[int] $age
Person([string] $name) {
$this.name = $name
}
Person([string]$name, [int]$age) {
$this.name = $name
$this.age n $age
}
}
Inheritance from Parent class to Child class
class ParentClass
{
[string] $meg = "It's under the parent class"
[string] getMessage()
{
return ("Message: {0}" -f $this.meg)
}
}
# bar extends Foo and inherits its members
class ChildClass : ParentClass
{
}
$Inherit = [ChildClass]::new()
so, $Inherit.meg will give you the "It's under the Parent Class"
Create a Module Manifest
@{
RootModule = 'myModule.psm1'
ModuleVersion = '1.0'
CompatiblePSEditions = @('Core')
GUID = '6382 ... 32x'
Author = 'Bob'
CompanyName = 'myCompany'
Copyright = '(c) 2018 all rights'
Description = 'It's description.'
FunctionsToExport = @()
CmdletsToExport = @()
VariablesToExport = @()
AliasesToExport = @()
DscResourcesToExport = @()
}
Simple Module Example
function Add {
[CmdletBind()]
param (
[int] $x
[int] $y
)
return $x + $y
}
Export-ModuleMember -Function Add
PowerShell profiles
A PowerShell profile is used to load user defined variables and functions automatically.
PowerShell profiles are not automatically created for users.
$PROFILE | Format-List -Force
$PROFILE.AllUsersAllHosts
Calculated Properties
Display file properties.
Get-ChildItem -Path C:\myDir | Select-Object Name, CreateTim, Length
# calcualted properties
Get-ChildItem -Path C:\myDir | Select-Object Name, @{name="Size_In_KB"; Expression={$_.Length / 1Kb}}
Using the .Net Math Class
Knowing which methods are available you can use:
[System.Math] | Get-Member -Static -MemberType Methods
Examples
[System.Math]::Floor(9.33) # 9
[System.Math]::Ceiling(9.333) # 10
[System.Math]::Pow(4,3) # 64
[System.Math]::Sqrt(49) # 7
Variables
$PSItem
Same as $_.
Get-Process | ForEach-Object -Process {
$PSItem.Name
}
$?
Contains the execution status of the last operation.
It contains TRUE if the last operation succeeded and FALSE if it failed.
Contains status of the last operation. When there is no error, it is set to Treu.
Write-Host "yes yes"
$? # True
Get-Process -Name nooo
Write-Host -Object "Was the last operation successful? $?"
$error
Contains an array of error objects that represent the most recent errors.
Get-Process -Name noooo
Write-Host -Object ('The last error that occurred was: {0}', -f $error[0].Exception.Message)
Remove error
$error.remove($error[0])
$OFS
Converting an array to a string. By default $OFS = " "
$arr = 1, 2, 3
$OFS = ",."
$arr # 1,.2,.3
Contains process ID of the current hosting process.
$pid
Splatting parameters
$MyParameters = @{
Name = "iexplore"
FileVersionInfo = $true
}
# splatting
Get-Process @MyParameters
# without splatting
Get-Process -Name "iexplore" -FileVersionInfo
Write Preferences
Write-Verbose "Detailed message"
Write-Information "Information Message"
Write-Debug "Debug Message"
Write-Progress "Progress Message"
Write-Warning "Warning Message"
Basic job creation
# Start a Script Block as background job:
$job = Start-Job -ScriptBlock {Get-Process}
# Start a script as background job
$job = Start-Job -FilePath "C:\yourScript.ps1"
Error Handle
Try
{
... Something Error ...
Stop-Process -Id 123456 -ErrorAction Stop
}
Catch
{
... Do Something ...
"Non-Terminating Error: Invalid Process ID"
}
Credential
輸出加密檔案xml
$credential = get-credential
$credential | Export-CliXml -Path 'C:\yourPath\cred.xml'
import加密檔案
$credential = Import-CliXml -Path 'C:\yourPath\cred.xml'
get-command
# It will display all s*.
get-command -Noun s*
Write-Host 和 Write-Output 差異
Write-Host # 只提供stdout功能(只有輸出)
Write-Output # 提供stdout和redirection
# example
$msg = Write-Output "Hello World!"
$msg
# output
# "Hello World!"
# alias "Echo" and "Write"
Set - Alias
Create a directory
Setting type with "-itemtype" and pass the parameter "directory".
New-Item -itemtype directory ExampleFolderName
sort
Example:
Get-ChildItem ./ | Sort-Object
# or
Get-ChildItem ./ | Sort
Tee
This command can save results in file or variable by pipelining.
Get-Process | Tee-Object -FilePath "C:\result.txt"
Get-Process notepad | Tee-Object -Variable prog
