Tipps und Tricks für Entwickler und IT-Interessierte
docker run -d --name=grafana -p 3000:3000 grafana/grafana-enterprise:10.0.0-ubuntu
The, start Browser with http://localhost:3000 and login with admin/admin
After Login, you have the possibility to change the password. We skip here for now.
export PYSPARK_DRIVER_PYTHON=jupyter export PYSPARK_DRIVER_PYTHON_OPTS='notebook'
Then, run
pyspark
Nicepage is an awesome Web Page Builder with 400+ Features and 10000+ Templates.
One of the features is to connect to Google Analytics, another is a Cookie Consent Plugin.
Unfortunately, i didn’t succeed in getting both together work. The goal was, only to load the GA code if the consent plugin allowed this.
So i created a workaround:
<script>
window.dataLayer = window.dataLayer || [];
function gtag(){
console.log('gtag: arguments=', arguments);
dataLayer.push(arguments);
}
function setupGoogleTagManager(w,d,s,l,i){
console.log('google tag manager: setup with', i);
w[l]=w[l]||[];
w[l].push({'gtm.start': new Date().getTime(), event:'gtm.js'});
var f=d.getElementsByTagName(s)[0],
j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';
j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;
f.parentNode.insertBefore(j,f);
}
function setCookie(cname, cvalue, exdays) {
const d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
let expires = "expires="+ d.toUTCString();
document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}
function getCookie(cname) {
let name = cname + "=";
let decodedCookie = decodeURIComponent(document.cookie);
let ca = decodedCookie.split(';');
for(let i = 0; i <ca.length; i++) {
let c = ca[i];
while (c.charAt(0) == ' ') {
c = c.substring(1);
}
if (c.indexOf(name) == 0) {
return c.substring(name.length, c.length);
}
}
return "";
}
function buildConsentCookie(consent) {
console.log('buildConsentCookie: consent=', consent);
const consentCookie = {
'functionality_storage': consent.necessary ? 'granted' : 'denied',
'security_storage': consent.necessary ? 'granted' : 'denied',
'ad_storage': consent.marketing ? 'granted' : 'denied',
'analytics_storage': consent.analytics ? 'granted' : 'denied',
'personalization': consent.preferences ? 'granted' : 'denied',
};
console.log('buildConsentCookie: consentCookie=', consentCookie);
return consentCookie
}
function setConsent(consent) {
console.log('setConsent: ', consent);
const consentCookie = buildConsentCookie(consent);
gtag('consent', 'default', consentCookie);
console.log('store consentMode: ',consentCookie);
localStorage.setItem('consentMode', JSON.stringify(consentCookie));
}
if(localStorage.getItem('consentMode') === null){
const consent = {
necessary: false,
marketing: false,
analytics: false,
preferences: false,
};
consentCookie = buildConsentCookie(consent);
gtag('consent', 'default', consentCookie);
} else {
consentCookie = JSON.parse(localStorage.getItem('consentMode'));
gtag('consent', 'default', consentCookie);
}
</script>
const consent = {
necessary: true,
marketing: true,
analytics: true,
preferences: true,
};
setCookie('u-gdpr-cookie', true, 180);
setConsent(consent);
setupGoogleTagManager(window,document,'script','dataLayer','GTM-#######');
Get-Command # List of all the commands available to PowerShell
# (native binaries in $env:PATH + cmdlets / functions from PowerShell modules)
Get-Command -Module Microsoft* # Lst of all the PowerShell commands exported from modules named Microsoft*
Get-Command -Name *item # List of all commands ending in "item"
Get-Help # Get all help topics
Get-Help -Name about_Variables # Get help for a specific about_* topic (aka. man page)
Get-Help -Name Get-Command # Get help for a specific PowerShell function
Get-Help -Name Get-Command -Parameter Module # Get help for a specific parameter on a specific command
###################################################
# Operators
###################################################
$a = 2 # Basic variable assignment operator
$a += 1 # Incremental assignment operator
$a -= 1 # Decrement assignment operator
$a -eq 0 # Equality comparison operator
$a -ne 5 # Not-equal comparison operator
$a -gt 2 # Greater than comparison operator
$a -lt 3 # Less than comparison operator
$FirstName = 'Trevor'
$FirstName -like 'T*' # Perform string comparison using the -like operator, which supports the wildcard (*) character. Returns $true
$BaconIsYummy = $true
$FoodToEat = $BaconIsYummy ? 'bacon' : 'beets' # Sets the $FoodToEat variable to 'bacon' using the ternary operator
'Celery' -in @('Bacon', 'Sausage', 'Steak', 'Chicken') # Returns boolean value indicating if left-hand operand exists in right-hand array
'Celery' -notin @('Bacon', 'Sausage', 'Steak') # Returns $true, because Celery is not part of the right-hand list
5 -is [string] # Is the number 5 a string value? No. Returns $false.
5 -is [int32] # Is the number 5 a 32-bit integer? Yes. Returns $true.
5 -is [int64] # Is the number 5 a 64-bit integer? No. Returns $false.
'Trevor' -is [int64] # Is 'Trevor' a 64-bit integer? No. Returns $false.
'Trevor' -isnot [string] # Is 'Trevor' NOT a string? No. Returns $false.
'Trevor' -is [string] # Is 'Trevor' a string? Yes. Returns $true.
$true -is [bool] # Is $true a boolean value? Yes. Returns $true.
$false -is [bool] # Is $false a boolean value? Yes. Returns $true.
5 -is [bool] # Is the number 5 a boolean value? No. Returns $false.
/pre>
###################################################
# Regular Expressions
###################################################
'Trevor' -match '^T\w*' # Perform a regular expression match against a string value. # Returns $true and populates $matches variable
$matches[0] # Returns 'Trevor', based on the above match
@('Trevor', 'Billy', 'Bobby') -match '^B' # Perform a regular expression match against an array of string values. Returns Billy, Bobby
$regex = [regex]'(\w{3,8})'
$regex.Matches('Trevor Bobby Dillon Joe Jacob').Value # Find multiple matches against a singleton string value.
/pre>
###################################################
# Flow Control
###################################################
if (1 -eq 1) { } # Do something if 1 is equal to 1
do { 'hi' } while ($false) # Loop while a condition is true (always executes at least once)
while ($false) { 'hi' } # While loops are not guaranteed to run at least once
while ($true) { } # Do something indefinitely
while ($true) { if (1 -eq 1) { break } } # Break out of an infinite while loop conditionally
for ($i = 0; $i -le 10; $i++) { Write-Host $i } # Iterate using a for..loop
foreach ($item in (Get-Process)) { } # Iterate over items in an array
switch ('test') { 'test' { 'matched'; break } } # Use the switch statement to perform actions based on conditions. Returns string 'matched'
switch -regex (@('Trevor', 'Daniel', 'Bobby')) { # Use the switch statement with regular expressions to match inputs
'o' { $PSItem; break } # NOTE: $PSItem or $_ refers to the "current" item being matched in the array
}
switch -regex (@('Trevor', 'Daniel', 'Bobby')) { # Switch statement omitting the break statement. Inputs can be matched multiple times, in this scenario.
'e' { $PSItem }
'r' { $PSItem }
}
/pre>
###################################################
# Variables
###################################################
$a = 0 # Initialize a variable
[int] $a = 'Trevor' # Initialize a variable, with the specified type (throws an exception)
[string] $a = 'Trevor' # Initialize a variable, with the specified type (doesn't throw an exception)
Get-Command -Name *varia* # Get a list of commands related to variable management
Get-Variable # Get an array of objects, representing the variables in the current and parent scopes
Get-Variable | ? { $PSItem.Options -contains 'constant' } # Get variables with the "Constant" option set
Get-Variable | ? { $PSItem.Options -contains 'readonly' } # Get variables with the "ReadOnly" option set
New-Variable -Name FirstName -Value Trevor
New-Variable FirstName -Value Trevor -Option Constant # Create a constant variable, that can only be removed by restarting PowerShell
New-Variable FirstName -Value Trevor -Option ReadOnly # Create a variable that can only be removed by specifying the -Force parameter on Remove-Variable
Remove-Variable -Name firstname # Remove a variable, with the specified name
Remove-Variable -Name firstname -Force # Remove a variable, with the specified name, that has the "ReadOnly" option set
/pre>
###################################################
# Functions
###################################################
function add ($a, $b) { $a + $b } # A basic PowerShell function
function Do-Something { # A PowerShell Advanced Function, with all three blocks declared: BEGIN, PROCESS, END
[CmdletBinding]()]
param ()
begin { }
process { }
end { }
}
/pre>
###################################################
# Working with Modules
###################################################
Get-Command -Name *module* -Module mic*core # Which commands can I use to work with modules?
Get-Module -ListAvailable # Show me all of the modules installed on my system (controlled by $env:PSModulePath)
Get-Module # Show me all of the modules imported into the current session
$PSModuleAutoLoadingPreference = 0 # Disable auto-loading of installed PowerShell modules, when a command is invoked
Import-Module -Name NameIT # Explicitly import a module, from the specified filesystem path or name (must be present in $env:PSModulePath)
Remove-Module -Name NameIT # Remove a module from the scope of the current PowerShell session
New-ModuleManifest # Helper function to create a new module manifest. You can create it by hand instead.
New-Module -Name trevor -ScriptBlock { # Create an in-memory PowerShell module (advanced users)
function Add($a,$b) { $a + $b } }
New-Module -Name trevor -ScriptBlock { # Create an in-memory PowerShell module, and make it visible to Get-Module (advanced users)
function Add($a,$b) { $a + $b } } | Import-Module
/pre>
################################################### # Module Management ################################################### Get-Command -Module PowerShellGet # Explore commands to manage PowerShell modules Find-Module -Tag cloud # Find modules in the PowerShell Gallery with a "cloud" tag Find-Module -Name ps* # Find modules in the PowerShell Gallery whose name starts with "PS" Install-Module -Name NameIT -Scope CurrentUser -Force # Install a module to your personal directory (non-admin) Install-Module -Name NameIT -Force # Install a module to your personal directory (admin / root) Install-Module -Name NameIT -RequiredVersion 1.9.0 # Install a specific version of a module Uninstall-Module -Name NameIT # Uninstall module called "NameIT", only if it was installed via Install-Module Register-PSRepository -Name <repo> -SourceLocation <uri> # Configure a private PowerShell module registry Unregister-PSRepository -Name <repo> # Deregister a PowerShell Repository /pre>
###################################################
# Filesystem
###################################################
New-Item -Path c:\test -ItemType Directory # Create a directory
mkdir c:\test2 # Create a directory (short-hand)
New-Item -Path c:\test\myrecipes.txt # Create an empty file
Set-Content -Path c:\test.txt -Value '' # Create an empty file
[System.IO.File]::WriteAllText('testing.txt', '') # Create an empty file using .NET Base Class Library
Remove-Item -Path testing.txt # Delete a file
[System.IO.File]::Delete('testing.txt') # Delete a file using .NET Base Class Library
/pre>
###################################################
# Hashtables (Dictionary)
###################################################
$Person = @{
FirstName = 'Trevor'
LastName = 'Sullivan'
Likes = @(
'Bacon',
'Beer',
'Software'
)
} # Create a PowerShell HashTable
$Person.FirstName # Retrieve an item from a HashTable
$Person.Likes[-1] # Returns the last item in the "Likes" array, in the $Person HashTable (software)
$Person.Age = 50 # Add a new property to a HashTable
/pre>
################################################### # Windows Management Instrumentation (WMI) (Windows only) ################################################### Get-CimInstance -ClassName Win32_BIOS # Retrieve BIOS information Get-CimInstance -ClassName Win32_DiskDrive # Retrieve information about locally connected physical disk devices Get-CimInstance -ClassName Win32_PhysicalMemory # Retrieve information about install physical memory (RAM) Get-CimInstance -ClassName Win32_NetworkAdapter # Retrieve information about installed network adapters (physical + virtual) Get-CimInstance -ClassName Win32_VideoController # Retrieve information about installed graphics / video card (GPU) Get-CimClass -Namespace root\cimv2 # Explore the various WMI classes available in the root\cimv2 namespace Get-CimInstance -Namespace root -ClassName __NAMESPACE # Explore the child WMI namespaces underneath the root\cimv2 namespace /pre>
###################################################
# Asynchronous Event Registration
###################################################
#### Register for filesystem events
$Watcher = [System.IO.FileSystemWatcher]::new('c:\tmp')
Register-ObjectEvent -InputObject $Watcher -EventName Created -Action {
Write-Host -Object 'New file created!!!'
}
#### Perform a task on a timer (ie. every 5000 milliseconds)
$Timer = [System.Timers.Timer]::new(5000)
Register-ObjectEvent -InputObject $Timer -EventName Elapsed -Action {
Write-Host -ForegroundColor Blue -Object 'Timer elapsed! Doing some work.'
}
$Timer.Start()
/pre>
################################################### # PowerShell Drives (PSDrives) ################################################### Get-PSDrive # List all the PSDrives on the system New-PSDrive -Name videos -PSProvider Filesystem -Root x:\data\content\videos # Create a new PSDrive that points to a filesystem location New-PSDrive -Name h -PSProvider FileSystem -Root '\\storage\h$\data' -Persist # Create a persistent mount on a drive letter, visible in Windows Explorer Set-Location -Path videos: # Switch into PSDrive context Remove-PSDrive -Name xyz # Delete a PSDrive /pre>
###################################################
# Data Management
###################################################
Get-Process | Group-Object -Property Name # Group objects by property name
Get-Process | Sort-Object -Property Id # Sort objects by a given property name
Get-Process | Where-Object -FilterScript { $PSItem.Name -match '^c' } # Filter objects based on a property matching a value
gps | where Name -match '^c' # Abbreviated form of the previous statement
/pre>
###################################################
# PowerShell Classes
###################################################
class Person {
[string] $FirstName # Define a class property as a string
[string] $LastName = 'Sullivan' # Define a class property with a default value
[int] $Age # Define a class property as an integer
Person() { # Add a default constructor (no input parameters) for a class
}
Person([string] $FirstName) { # Define a class constructor with a single string parameter
$this.FirstName = $FirstName
}
[string] FullName() {
return '{0} {1}' -f $this.FirstName, $this.LastName
}
}
$Person01 = [Person]::new() # Instantiate a new Person object.
$Person01.FirstName = 'Trevor' # Set the FirstName property on the Person object.
$Person01.FullName() # Call the FullName() method on the Person object. Returns 'Trevor Sullivan'
class Server { # Define a "Server" class, to manage remote servers. Customize this based on your needs.
[string] $Name
[System.Net.IPAddress] $IPAddress # Define a class property as an IPaddress object
[string] $SSHKey = "$HOME/.ssh/id_rsa" # Set the path to the private key used to authenticate to the server
[string] $Username # Set the username to login to the remote server with
RunCommand([string] $Command) { # Define a method to call a command on the remote server, via SSH
ssh -i $this.SSHKey $this.Username@$this.Name $this.Command
}
}
$Server01 = [Server]::new() # Instantiate the Server class as a new object
$Server01.Name = 'webserver01.local' # Set the "name" of the remote server
$Server01.Username = 'root' # Set the username property of the "Server" object
$Server01.RunCommand("hostname") # Run a command on the remote server
/pre>
###################################################
# REST APIs
###################################################
$Params = @{
Uri = 'https://api.github.com/events'
Method = 'Get'
}
Invoke-RestMethod @Params # Call a REST API, using the HTTP GET method
# Single line comments start with a number symbol. <# Multi-line comments like so #> /pre>
####################################################
## 1. Primitive Datatypes and Operators
####################################################
# Numbers
3 # => 3
# Math
1 + 1 # => 2
8 - 1 # => 7
10 * 2 # => 20
35 / 5 # => 7.0
# Powershell uses banker's rounding,
# meaning [int]1.5 would round to 2 but so would [int]2.5
# Division always returns a float.
# You must cast result to [int] to round.
[int]5 / [int]3 # => 1.66666666666667
[int]-5 / [int]3 # => -1.66666666666667
5.0 / 3.0 # => 1.66666666666667
-5.0 / 3.0 # => -1.66666666666667
[int]$result = 5 / 3
$result # => 2
# Modulo operation
7 % 3 # => 1
# Exponentiation requires longform or the built-in [Math] class.
[Math]::Pow(2,3) # => 8
# Enforce order of operations with parentheses.
1 + 3 * 2 # => 7
(1 + 3) * 2 # => 8
# Boolean values are primitives (Note: the $)
$True # => True
$False # => False
# negate with !
!$True # => False
!$False # => True
# Boolean Operators
# Note "-and" and "-or" usage
$True -and $False # => False
$False -or $True # => True
# True and False are actually 1 and 0 but only support limited arithmetic.
# However, casting the bool to int resolves this.
$True + $True # => 2
$True * 8 # => '[System.Boolean] * [System.Int32]' is undefined
[int]$True * 8 # => 8
$False - 5 # => -5
# Comparison operators look at the numerical value of True and False.
0 -eq $False # => True
1 -eq $True # => True
2 -eq $True # => False
-5 -ne $False # => True
# Using boolean logical operators on ints casts to booleans for evaluation.
# but their non-cast value is returned
# Don't mix up with bool(ints) and bitwise -band/-bor
[bool](0) # => False
[bool](4) # => True
[bool](-6) # => True
0 -band 2 # => 0
-5 -bor 0 # => -5
# Equality is -eq (equals)
1 -eq 1 # => True
2 -eq 1 # => False
# Inequality is -ne (notequals)
1 -ne 1 # => False
2 -ne 1 # => True
# More comparisons
1 -lt 10 # => True
1 -gt 10 # => False
2 -le 2 # => True
2 -ge 2 # => True
# Seeing whether a value is in a range
1 -lt 2 -and 2 -lt 3 # => True
2 -lt 3 -and 3 -lt 2 # => False
# (-is vs. -eq) -is checks if two objects are the same type.
# -eq checks if the objects have the same values.
# Note: we called '[Math]' from .NET previously without the preceeding
# namespaces. We can do the same with [Collections.ArrayList] if preferred.
[System.Collections.ArrayList]$a = @() # Point a at a new list
$a = (1,2,3,4)
$b = $a # => Point b at what a is pointing to
$b -is $a.GetType() # => True, a and b equal same type
$b -eq $a # => True, a and b values are equal
[System.Collections.Hashtable]$b = @{} # => Point a at a new hash table
$b = @{'one' = 1
'two' = 2}
$b -is $a.GetType() # => False, a and b types not equal
# Strings are created with " or ' but " is required for string interpolation
"This is a string."
'This is also a string.'
# Strings can be added too! But try not to do this.
"Hello " + "world!" # => "Hello world!"
# A string can be treated like a list of characters
"Hello world!"[0] # => 'H'
# You can find the length of a string
("This is a string").Length # => 16
# You can also format using f-strings or formatted string literals.
$name = "Steve"
$age = 22
"He said his name is $name."
# => "He said his name is Steve"
"{0} said he is {1} years old." -f $name, $age
# => "Steve said he is 22 years old"
"$name's name is $($name.Length) characters long."
# => "Steve's name is 5 characters long."
# Escape Characters in Powershell
# Many languages use the '\', but Windows uses this character for
# file paths. Powershell thus uses '`' to escape characters
# Take caution when working with files, as '`' is a
# valid character in NTFS filenames.
"Showing`nEscape Chars" # => new line between Showing and Escape
"Making`tTables`tWith`tTabs" # => Format things with tabs
# Negate pound sign to prevent comment
# Note that the function of '#' is removed, but '#' is still present
`#Get-Process # => Fail: not a recognized cmdlet
# $null is not an object
$null # => None
# $null, 0, and empty strings and arrays all evaluate to False.
# All other values are True
function Test-Value ($value) {
if ($value) {
Write-Output 'True'
}
else {
Write-Output 'False'
}
}
Test-Value ($null) # => False
Test-Value (0) # => False
Test-Value ("") # => False
Test-Value [] # => True
# *[] calls .NET class; creates '[]' string when passed to function
Test-Value ({}) # => True
Test-Value @() # => False
/pre>
####################################################
## 2. Variables and Collections
####################################################
# Powershell uses the "Write-Output" function to print
Write-Output "I'm Posh. Nice to meet you!" # => I'm Posh. Nice to meet you!
# Simple way to get input data from console
$userInput = Read-Host "Enter some data: " # Returns the data as a string
# There are no declarations, only assignments.
# Convention is to use camelCase or PascalCase, whatever your team uses.
$someVariable = 5
$someVariable # => 5
# Accessing a previously unassigned variable does not throw exception.
# The value is $null by default
# Ternary Operators exist in Powershell 7 and up
0 ? 'yes' : 'no' # => no
# The default array object in Powershell is an fixed length array.
$defaultArray = "thing","thing2","thing3"
# you can add objects with '+=', but cannot remove objects.
$defaultArray.Add("thing4") # => Exception "Collection was of a fixed size."
# To have a more workable array, you'll want the .NET [ArrayList] class
# It is also worth noting that ArrayLists are significantly faster
# ArrayLists store sequences
[System.Collections.ArrayList]$array = @()
# You can start with a prefilled ArrayList
[System.Collections.ArrayList]$otherArray = @(4, 5, 6)
# Add to the end of a list with 'Add' (Note: produces output, append to $null)
$array.Add(1) > $null # $array is now [1]
$array.Add(2) > $null # $array is now [1, 2]
$array.Add(4) > $null # $array is now [1, 2, 4]
$array.Add(3) > $null # $array is now [1, 2, 4, 3]
# Remove from end with index of count of objects-1; array index starts at 0
$array.RemoveAt($array.Count-1) # => 3 and array is now [1, 2, 4]
# Let's put it back
$array.Add(3) > $null # array is now [1, 2, 4, 3] again.
# Access a list like you would any array
$array[0] # => 1
# Look at the last element
$array[-1] # => 3
# Looking out of bounds returns nothing
$array[4] # blank line returned
# You can look at ranges with slice syntax.
# The start index is included, the end index is not
# (It's a closed/open range for you mathy types.)
$array[1..3] # Return array from index 1 to 3 => [2, 4]
$array[2..-1] # Return array starting from index 2 => [4, 3]
$array[0..3] # Return array from beginning until index 3 => [1, 2, 4]
$array[0..2] # Return array selecting every second entry => [1, 4]
$array.Reverse() # mutates array to reverse order => [3, 4, 2, 1]
# Use any combination of these to make advanced slices
# Remove arbitrary elements from a array with "del"
$array.Remove($array[2]) # $array is now [1, 2, 3]
# Insert an element at a specific index
$array.Insert(1, 2) # $array is now [1, 2, 3] again
# Get the index of the first item found matching the argument
$array.IndexOf(2) # => 1
$array.IndexOf(6) # Returns -1 as "outside array"
# You can add arrays
# Note: values for $array and for $otherArray are not modified.
$array + $otherArray # => [1, 2, 3, 4, 5, 6]
# Concatenate arrays with "AddRange()"
$array.AddRange($otherArray) # Now $array is [1, 2, 3, 4, 5, 6]
# Check for existence in a array with "in"
1 -in $array # => True
# Examine length with "Count" (Note: "Length" on arrayList = each items length)
$array.Count # => 6
# Tuples are like arrays but are immutable.
# To use Tuples in powershell, you must use the .NET tuple class.
$tuple = [System.Tuple]::Create(1, 2, 3)
$tuple.Item(0) # => 1
$tuple.Item(0) = 3 # Raises a TypeError
# You can do some of the array methods on tuples, but they are limited.
$tuple.Length # => 3
$tuple + (4, 5, 6) # => Exception
$tuple[0..2] # => $null
2 -in $tuple # => False
# Hashtables store mappings from keys to values, similar to Dictionaries.
$emptyHash = @{}
# Here is a prefilled dictionary
$filledHash = @{"one"= 1
"two"= 2
"three"= 3}
# Look up values with []
$filledHash["one"] # => 1
# Get all keys as an iterable with ".Keys".
# items maintain the order at which they are inserted into the dictionary.
$filledHash.Keys # => ["one", "two", "three"]
# Get all values as an iterable with ".Values".
$filledHash.Values # => [1, 2, 3]
# Check for existence of keys or values in a hash with "-in"
"one" -in $filledHash.Keys # => True
1 -in $filledHash.Values # => False
# Looking up a non-existing key returns $null
$filledHash["four"] # $null
# Adding to a dictionary
$filledHash.Add("five",5) # $filledHash["five"] is set to 5
$filledHash.Add("five",6) # exception "Item with key "five" has already been added"
$filledHash["four"] = 4 # $filledHash["four"] is set to 4, running again does nothing
# Remove keys from a dictionary with del
$filledHash.Remove("one") # Removes the key "one" from filled dict
/pre>
####################################################
## 3. Control Flow and Iterables
####################################################
# Let's just make a variable
$someVar = 5
# Here is an if statement.
# This prints "$someVar is smaller than 10"
if ($someVar -gt 10) {
Write-Output "$someVar is bigger than 10."
}
elseif ($someVar -lt 10) { # This elseif clause is optional.
Write-Output "$someVar is smaller than 10."
}
else { # This is optional too.
Write-Output "$someVar is indeed 10."
}
<#
Foreach loops iterate over arrays
prints:
dog is a mammal
cat is a mammal
mouse is a mammal
#>
foreach ($animal in ("dog", "cat", "mouse")) {
# You can use -f to interpolate formatted strings
"{0} is a mammal" -f $animal
}
<#
For loops iterate over arrays and you can specify indices
prints:
0 a
1 b
2 c
3 d
4 e
5 f
6 g
7 h
#>
$letters = ('a','b','c','d','e','f','g','h')
for($i=0; $i -le $letters.Count-1; $i++){
Write-Host $i, $letters[$i]
}
<#
While loops go until a condition is no longer met.
prints:
0
1
2
3
#>
$x = 0
while ($x -lt 4) {
Write-Output $x
$x += 1 # Shorthand for x = x + 1
}
# Switch statements are more powerful 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 }
default { "Others" }
}
# Handle exceptions with a try/catch block
try {
# Use "throw" to raise an error
throw "This is an error"
}
catch {
Write-Output $Error.ExceptionMessage
}
finally {
Write-Output "We can clean up resources here"
}
# Writing to a file
$contents = @{"aa"= 12
"bb"= 21}
$contents | Export-CSV "$env:HOMEDRIVE\file.csv" # writes to a file
$contents = "test string here"
$contents | Out-File "$env:HOMEDRIVE\file.txt" # writes to another file
# Read file contents and convert to json
Get-Content "$env:HOMEDRIVE\file.csv" | ConvertTo-Json
/pre>
####################################################
## 4. Functions
####################################################
# Use "function" to create new functions
# Keep the Verb-Noun naming convention for functions
function Add-Numbers {
$args[0] + $args[1]
}
Add-Numbers 1 2 # => 3
# Calling functions with parameters
function Add-ParamNumbers {
param( [int]$firstNumber, [int]$secondNumber )
$firstNumber + $secondNumber
}
Add-ParamNumbers -FirstNumber 1 -SecondNumber 2 # => 3
# Functions with named parameters, parameter attributes, parsable documentation
<#
.SYNOPSIS
Setup a new website
.DESCRIPTION
Creates everything your new website needs for much win
.PARAMETER siteName
The name for the new website
.EXAMPLE
New-Website -Name FancySite -Po 5000
New-Website SiteWithDefaultPort
New-Website siteName 2000 # ERROR! Port argument could not be validated
('name1','name2') | New-Website -Verbose
#>
function New-Website() {
[CmdletBinding()]
param (
[Parameter(ValueFromPipeline=$true, Mandatory=$true)]
[Alias('name')]
[string]$siteName,
[ValidateSet(3000,5000,8000)]
[int]$port = 3000
)
BEGIN { Write-Output 'Creating new website(s)' }
PROCESS { Write-Output "name: $siteName, port: $port" }
END { Write-Output 'Website(s) created' }
}
/pre>
####################################################
## 5. Modules
####################################################
# You can import modules and install modules
# The Install-Module is similar to pip or npm, pulls from Powershell Gallery
Install-Module dbaTools
Import-Module dbaTools
$query = "SELECT * FROM dbo.sometable"
$queryParams = @{
SqlInstance = 'testInstance'
Database = 'testDatabase'
Query = $query
}
Invoke-DbaQuery @queryParams
# You can get specific functions from a module
Import-Module -Function Invoke-DbaQuery
# Powershell modules are just ordinary Posh files. You
# can write your own, and import them. The name of the
# module is the same as the name of the file.
# You can find out which functions and attributes
# are defined in a module.
Get-Command -module dbaTools
Get-Help dbaTools -Full
/pre>
####################################################
## 6. Classes
####################################################
# We use the "class" statement to create a class
class Instrument {
[string]$Type
[string]$Family
}
$instrument = [Instrument]::new()
$instrument.Type = "String Instrument"
$instrument.Family = "Plucked String"
$instrument
<# Output:
Type Family
---- ------
String Instrument Plucked String
#>
/pre>
####################################################
## 6.1 Inheritance
####################################################
# Inheritance allows new child classes to be defined that inherit
# methods and variables from their parent class.
class Guitar : Instrument
{
[string]$Brand
[string]$SubType
[string]$ModelType
[string]$ModelNumber
}
$myGuitar = [Guitar]::new()
$myGuitar.Brand = "Taylor"
$myGuitar.SubType = "Acoustic"
$myGuitar.ModelType = "Presentation"
$myGuitar.ModelNumber = "PS14ce Blackwood"
$myGuitar.GetType()
<#
IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True False Guitar Instrument
#>
/pre>
####################################################
## 7. Advanced
####################################################
# The powershell pipeline allows things like High-Order Functions.
# Group-Object is a handy cmdlet that does incredible things.
# It works much like a GROUP BY in SQL.
<#
The following will get all the running processes,
group them by Name,
and tell us how many instances of each process we have running.
Tip: Chrome and svcHost are usually big numbers in this regard.
#>
Get-Process | Foreach-Object ProcessName | Group-Object
# Useful pipeline examples are iteration and filtering.
1..10 | ForEach-Object { "Loop number $PSITEM" }
1..10 | Where-Object { $PSITEM -gt 5 } | ConvertTo-Json
# A notable pitfall of the pipeline is it's performance when
# compared with other options.
# Additionally, raw bytes are not passed through the pipeline,
# so passing an image causes some issues.
# See more on that in the link at the bottom.
<#
Asynchronous functions exist in the form of jobs.
Typically a procedural language,
Powershell can operate non-blocking functions when invoked as Jobs.
#>
# This function is known to be non-optimized, and therefore slow.
$installedApps = Get-CimInstance -ClassName Win32_Product
# If we had a script, it would hang at this func for a period of time.
$scriptBlock = {Get-CimInstance -ClassName Win32_Product}
Start-Job -ScriptBlock $scriptBlock
# This will start a background job that runs the command.
# You can then obtain the status of jobs and their returned results.
$allJobs = Get-Job
$jobResponse = Get-Job | Receive-Job
# Math is built in to powershell and has many functions.
$r=2
$pi=[math]::pi
$r2=[math]::pow( $r, 2 )
$area = $pi*$r2
$area
# To see all possibilities, check the members.
[System.Math] | Get-Member -Static -MemberType All
<#
This is a silly one:
You may one day be asked to create a func that could take $start and $end
and reverse anything in an array within the given range
based on an arbitrary array without mutating the original array.
Let's see one way to do that and introduce another data structure.
#>
$targetArray = 'a','b','c','d','e','f','g','h','i','j','k','l','m'
function Format-Range ($start, $end, $array) {
[System.Collections.ArrayList]$firstSectionArray = @()
[System.Collections.ArrayList]$secondSectionArray = @()
[System.Collections.Stack]$stack = @()
for ($index = 0; $index -lt $array.Count; $index++) {
if ($index -lt $start) {
$firstSectionArray.Add($array[$index]) > $null
}
elseif ($index -ge $start -and $index -le $end) {
$stack.Push($array[$index])
}
else {
$secondSectionArray.Add($array[$index]) > $null
}
}
$finalArray = $firstSectionArray + $stack.ToArray() + $secondSectionArray
return $finalArray
}
Format-Range 2 6 $targetArray
# => 'a','b','g','f','e','d','c','h','i','j','k','l','m'
# The previous method works, but uses extra memory by allocating new arrays.
# It's also kind of lengthy.
# Let's see how we can do this without allocating a new array.
# This is slightly faster as well.
function Format-Range ($start, $end) {
while ($start -lt $end)
{
$temp = $targetArray[$start]
$targetArray[$start] = $targetArray[$end]
$targetArray[$end] = $temp
$start++
$end--
}
return $targetArray
}
Format-Range 2 6 # => 'a','b','g','f','e','d','c','h','i','j','k','l','m'
# 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-WinEvent # Display GUI to fill in the parameters
Update-Help # Run as admin
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
# Calling external commands, executables,
# and functions with the call operator.
# Exe paths with arguments passed or containing spaces can create issues.
C:\Program Files\dotnet\dotnet.exe
# The term 'C:\Program' is not recognized as a name of a cmdlet,
# function, script file, or executable program.
# Check the spelling of the name, or if a path was included,
# verify that the path is correct and try again
"C:\Program Files\dotnet\dotnet.exe"
C:\Program Files\dotnet\dotnet.exe # returns string rather than execute
&"C:\Program Files\dotnet\dotnet.exe --help" # fail
&"C:\Program Files\dotnet\dotnet.exe" --help # success
# Alternatively, you can use dot-sourcing here
."C:\Program Files\dotnet\dotnet.exe" --help # success
# the call operator (&) is similar to Invoke-Expression,
# but IEX runs in current scope.
# One usage of '&' would be to invoke a scriptblock inside of your script.
# Notice the variables are scoped
$i = 2
$scriptBlock = { $i=5; Write-Output $i }
& $scriptBlock # => 5
$i # => 2
invoke-expression ' $i=5; Write-Output $i ' # => 5
$i # => 5
# Alternatively, to preserve changes to public variables
# you can use "Dot-Sourcing". This will run in the current scope.
$x=1
&{$x=2};$x # => 1
.{$x=2};$x # => 2
# Remoting into computers is easy.
Enter-PSSession -ComputerName RemoteComputer
# Once remoted in, you can run commands as if you're local.
RemoteComputer\PS> Get-Process powershell
<#
Handles NPM(K) PM(K) WS(K) CPU(s) Id SI ProcessName
------- ------ ----- ----- ------ -- -- -----------
1096 44 156324 179068 29.92 11772 1 powershell
545 25 49512 49852 25348 0 powershell
#>
RemoteComputer\PS> Exit-PSSession
<#
Powershell is an incredible tool for Windows management and Automation.
Let's take the following scenario:
You have 10 servers.
You need to check whether a service is running on all of them.
You can RDP and log in, or PSSession to all of them, but why?
Check out the following
#>
$serverList = @(
'server1',
'server2',
'server3',
'server4',
'server5',
'server6',
'server7',
'server8',
'server9',
'server10'
)
[scriptblock]$script = {
Get-Service -DisplayName 'Task Scheduler'
}
foreach ($server in $serverList) {
$cmdSplat = @{
ComputerName = $server
JobName = 'checkService'
ScriptBlock = $script
AsJob = $true
ErrorAction = 'SilentlyContinue'
}
Invoke-Command @cmdSplat | Out-Null
}
<#
Here we've invoked jobs across many servers.
We can now Receive-Job and see if they're all running.
Now scale this up 100x as many servers :)
#>
Cmdlets are PowerShell’s internal commands. These cmdlets will return one or more objects to the pipeline where at the end of that pipeline, we mention some properties of the objects in the following table to see their values displayed on the screen.
| Command | Description |
Get-Help | This command allows you to get support with PowerShell. |
Get-PSdrive | This command offers you a list of available PSDrives, such as c, env, hklm, hkcu, alias, etc. |
Get-ChildItem | In any registry, children are the subkeys of the current key. To get the required details, you can use the following command. |
Get-ChildItem -recurse | Run this command to list all the children recursively of the current PSdrive, folder, or registry key. |
Get-ChildItem -rec -force | Use this command To include the hidden folders (directories). |
(Get-ChildItem).name or Get-ChildItem -name | Run any of these commands to get the list file and directory names in the current folder. |
(Get-ChildItem).count | Use this command to get the number of entries in the collection of objects returned by the Get-Children. |
PSdrives are the collection of entities grouped together so they can be accessed as a filesystem drive. The “PSprovider” does this grouping.
By default, a PS session can access several PSdrives including c:, env:, alias:, and HKLM:, where c: refers to the usual Windows c-drive; env: is the space of Windows environmental variables; alias: is the collection of cmdlet aliases; and HKLM is a hive in the registry.
Any PS session will enter the user’s home folder. If you want to switch from a PS session to another PSdrive and retrieve the information from that drive, consider the following commands:
| Commands | Description |
Switching to env- | The prompt character will change to the “ENV:\>”. Set-Location env by running the following command: Set-Location env- |
Env:\> Get-Childitem | This command will get you all the environment variables. |
Env:\> Get-Childitem userprofile | Use this command to get the environment variables of “userprofile.” |
Env:\> Set-Location alias: | Run the following command to change the prompt character to “Alias.” |
Alias:\> Get-Childitem | Run this command to get all the children of all aliases. |
Alias:\> Set-Location C:\ | Use this command to get the “C:/>” prompt again, back to the default drive. |
C:\Users\user_name>$alias:ls | Run this command to find what alias “ls” stands for. |
Cmdlets uses the pipelines to pass the objects but not the character streams like Unix. The pipeline character is | (ASCII 124), followed by a command that handles the output passed through the pipeline. The pipeline consists of the following three stages.
Get-ChildItem *.txt | Where-Object length -lt 1000 | Sort-Object length
The following table highlights some of the basic pipeline commands:
| Command | Description |
(Get-Item /Users/praashibansal/Desktop).lastwritetime.year | Easily sets the value of the ‘lastwritetime.year’ property to the present date and time without affecting the file’s content. |
(Get-ChildItem data.txt.rtf -name).name # -> null | Provides an empty result |
"data.txt.rtf" | Rename-Item -NewName "data_new.txt.rtf" | Changes the old file names and file extensions to the new ones |
Get-ChildItem data.txt | Rename-Item -new {$_.name} | A trivial renaming command that invokes an automatic variable |
Get-ChildItem data.txt.rtf -name | Rename-Item -new {$_.name} | If the piped object $_ doesn’t have the member property (name), you will receive an error, as parameter $_.name is null |
Get-ChildItem | Select-Object basename | Sort-Object * | Displays the list of the names of all the files that are present in the current folder sorted in alphabetical order. |
Move-Item *.txt subdirectory | Moves all the files to the folder subdirectory |
Get-ChildItem *.txt | Move-Item ..\ | Gives the error message that Move-Item lacks input |
Cmdlets come with several aliases. The following table highlights a few of aliases, along with their descriptions:
| Command | Description |
Add-Content | Appends value to a file |
Get-Content | Finds file content in an array |
Set-Location | Changes folder, key, or PS drive |
Clear-Host | Clears console |
Remove-Item | Delete files |
Get-ChildItem -Path .\ | Lists Folder, Key, or PSDrive Children |
Write-Output | Sends the array to the console, pipeline, or redirect it to the file |
Foreach-Object | Traverses each object in a pipeline |
Format-Table | Formats the table with selected properties for each object in each column |
Format-List | Formats the process properties by name |
Get-Alias | Provides Cmdlet Alias |
Get-Command | Provides you with commands from the current session only |
Get-Member | Retrieves all the object members |
Get-ItemProperty .\data.txt | Format-List | Provides the specified item’s properties |
Get-ItemPropertyValue -Path '.\data.txt' -Name LastWriteTime | Gives the current value for a specified property while using the name parameter |
Get-Variable m* | Finds session variable names and sessions |
New-Item -Path .\ -Name "testfile1.txt" -ItemType "file" -Value "This is a text string." | Creates a new file, directory, symbolic link, registry key, or registry entry |
Get-Process | Gives the entire list of all the running processes |
Get-Location | Provides the current directory’s or registry key’s location |
Rename-Item -Path “old_name” -NewName “new_name” | Renames the old item name with the new name |
Remove-Item .\testfile1.txt | Removes the specified directory, files, or registry keys |
Remove-Variable | Removes the specified variable |
Start-Sleep | Suspends an activity for a specified period of time |
| Operator | Description | Example |
| + | Adds integers; concatenates | 6 + 2 |
| strings, arrays, and hash tables. | “file” + “name”@(1, “one”) + @(2.0, “two”)@{“one” = 1} + @{“two” = 2} | |
| + | Makes a number out of an object | 123 |
| – | Subtracts one value from another | 6 – 2 |
| – | Calculates the opposite number | – -6 |
| (Get-Date).AddDays(-1) | ||
| * | Multiply numbers or copy strings and arrays for a specified number of times | 6 * 2 |
| @(“!”) * 4 | ||
| “!” * 3 | ||
| / | Divides two values | 6 / 2 |
| % | Modulus – returns the remainder of a division operation | 7 % 2 |
| -band | Bitwise AND | 5 -band 3 |
| -bnot | Bitwise NOT | -bnot 5 |
| -bor | Bitwise OR | 5 -bor 0x03 |
| -bxor | Bitwise XOR | 5 -bxor 3 |
| -shl | Shifts bits to the left | 102 -shl 2 |
| -shr | Shifts bits to the right | 102 -shr 2 |
| Precedence | Operator | Description |
| 1 | () | Parentheses |
| 2 | – | For a negative number or unary operator |
| 3 | *, /, % | For multiplication and division |
| 4 | +,- | For addition and subtraction |
| 5 | -band, -bnot, -bor, -bxor, -shr, and -shl | For bitwise operations |
| Operator | Description |
| = | Sets a variable’s value to the specified value |
| += | Increases a variable’s value by the specified value or appends the specified value to the existing value |
| -= | Decreases a variable’s value by a specified value |
| *= | Multiplies a variable’s value by a specified value, or appends the specified value to the existing value |
| /= | Divides a variable’s value by a specified value |
| %= | Divides the variable’s value by a specified value and then assigns the remainder (modulus) to the variable. |
| #ERROR! | Increases a variable’s value, assignable property, or array element by 1. |
| — | Decreases the variable’s value, assignable property, or array element by 1. |
| Type | Operator | Comparison test |
| Equality | -eq | equals |
| -ne | not equals | |
| -gt | greater than | |
| -ge | greater than or equal | |
| -lt | less than | |
| -le | less than or equal | |
| Matching | -like | string matches wildcard pattern |
| -notlike | string doesn’t match wildcard pattern | |
| -match | string matches regex pattern | |
| -notmatch | string doesn’t match regex pattern | |
| Replacement | -replace | replaces strings matching a regex pattern |
| Containment | -contains | collection contains a value |
| -notcontains | collection doesn’t contain a value | |
| -in | value is in a collection | |
| -notin | value is not in a collection | |
| Type | -is | both objects are the same type |
| -isnot | objects are not the same type |
| Operator | Description | Example |
| -and | Logical AND. TRUE when both statements are true. | (1 -eq 1) -and (1 -eq 2) FALSE |
| -or | Logical OR. TRUE when either of the statements is TRUE. | (1 -eq 1) -or (1 -eq 2)TRUE |
| -xor | Logical EXCLUSIVE OR. TRUE when only one statement is TRUE. | (1 -eq 1) -xor (2 -eq 2)FALSE |
| -not | Logical not. Negates the statement that follows. | -not (1 -eq 1)FLASE |
| ! | Same as -not | !(1 -eq 1)FALSE |
| Operator | Description | Syntax |
| > | Send specified stream to a file | n> |
| >> | Append specified stream to a file | n>> |
| >&1 | Redirects the specified stream to the Success stream | n>&1 |
| Operator | Description | Example |
| -isNot | Returns TRUE when the input not an instance of thespecified.NET type. | (get-date) -isNot [DateTime]FALSE |
| -as | Converts the input to the specified .NET type. | “5/7/07” -as [DateTime]Monday, May 7, 2007 00:00:00 |
| Operator | Description |
| () Grouping Operator | Allows you to override operator precedence in expressions |
| &() Subexpression Operator | Gives you the result of one or more statements |
| @( ) Array Subexpression Operator | Returns the results of one or more statements in the form of arrays. |
| & Background Operator | The pipeline before & is executed by this command in a Powershell job. |
| [] Cast Operator | Converts objects to the specific type. |
A regular expression is a pattern that is used to match text that includes literal characters, operators, and other constructs. PowerShell regular expressions are case-insensitive by default.
| Method | Case Sensitivity |
| Select-String | use -CaseSensitive switch |
| switch statement | use the -casesensitive option |
| operators | prefix with ‘c’ (-cmatch, -csplit, or -creplace) |
A regular expression can be a literal character or a string.
These allow you to match any number of characters one time, while [^character group] only matches characters NOT in the group.
A pattern can also be a range of characters. The characters can be alphabetic [A-Z], numeric [0-9], or even ASCII-based [ -~] (all printable characters).
The \d character class will match any decimal digit. Conversely, \D will match any non-decimal digit.
The \w character class will match any word character [a-zA-Z_0-9]. To match any non-word character, use \W.
The period (.) is a wildcard character in regular expressions. It will match any character except a newline (\n).
Whitespace is matched using the \s character class. Any non-whitespace character is matched using \S. Literal space characters ‘ ‘ can also be used.
The backslash (\) is used to escape characters so the regular expression engine doesn’t parse them.
The following characters are reserved: []().\^$|?*+{}.
> '3.141' -match '3\.\d{2,]'
True
The regular expressions with the -replace operator allows you to dynamically replace text using captured text.
<input> -replace <original>, <substitute>
ForEach-Object is a cmdlet that allows you to iterate through items in a pipeline, such as with PowerShell one-liners. ForEach-Object will stream the objects through the pipeline.
Although the Module parameter of Get-Command accepts multiple values that are strings, it will only accept them via pipeline input using the property name, or parameter input.
If you want to pipe two strings by value to Get-Command for use with the Module parameter, use the ForEach-Objectcmdlet:
$ComputerName = 'DC01', 'WEB01'
foreach ($Computer in $ComputerName) {
Get-ADComputer -Identity $Computer
}
A “for” loop iterates while a specified condition is true.
For example:
for ($i = 1; $i -lt 5; $i++) {
Write-Output "Sleeping for $i seconds"
Start-Sleep -Seconds $i
}
There are two different “do” loops in PowerShell. Do Until runs while the specified condition is false.
Example 1:
$number = Get-Random -Minimum 1 -Maximum 10
do {
$guess = Read-Host -Prompt "What's your guess?"
if ($guess -lt $number) {
Write-Output 'Too low!'
} elseif ($guess -gt $number) {
Write-Output 'Too high!'
}
}
until ($guess -eq $number)
Example 2:
$number = Get-Random -Minimum 1 -Maximum 10
do {
$guess = Read-Host -Prompt "What's your guess?"
if ($guess -lt $number) {
Write-Output 'Too low!'
} elseif ($guess -gt $number) {
Write-Output 'Too high!'
}
}
while ($guess -ne $number)
Similar to the Do While loop, a While loop runs as long as the specified condition is true. The difference however, is that a While loop evaluates the condition at the top of the loop before any code is run. So, it doesn’t run if the condition evaluates to false.
For example:
$date = Get-Date -Date 'November 22'
while ($date.DayOfWeek -ne 'Thursday') {
$date = $date.AddDays(1)
}
Write-Output $date
PowerShell allows you to store all types of values. For example, it can store command results and command expression elements like names, paths, and settings. Here are some of PowerShell’s different variables.
To create a new variable, you need to use an assignment statement and assign a value to the variable. There is no need to declare the variable before using it. The default value of all variables is $null.
For example:
$MyVariable = 1, 2, 3 $MyVariable
Use a Pascal case name with an approved verb and a singular noun to name a function. You can get a list of approved verbs by running Get-Verb:
Get-Verb | Sort-Object -Property Verb
Use a function keyword followed by the function name to create a simple function. Then, use an open and closing curly brace. The function will execute code contained within those curly braces.
For example:
function Get-Version {
$PSVersionTable.PSVersion
}
A module is a package containing PowerShell members, such as cmdlets, providers, functions, workflows, variables, and aliases. You can implement package members in a PowerShell script, a compiled DLL, or both. PowerShell automatically imports the modules the first time you run any command in an installed module. You can use the commands in a module without setting up or profile configuration.
To use any module, you need to first install them. Then, find the command that comes with the module and use them.
If you get a module as a folder, install it before you use it on the PowerShell command line. Some modules are preinstalled. You can use the following command to create a Modules directory for the current user:
New-Item -Type Directory -Path $HOME\Documents\PowerShell\Modules
Copy the entire module folder into the Modules directory. You can use any method to copy the folder, including Windows Explorer, Cmd.exe, and PowerShell.
Run the following to find the modules installed in a default module location (not imported).
Get-Module -ListAvailable
Run the following command to find a module’s commands:
Get-Command -Module <module-name> Get-Command -Module Microsoft.PowerShell.Archive
Run the following command with the proper module name:
Import-Module <module-name>
You can run the following command with the proper module name:
Remove-Module <module-name>
Use the following command to view default module locations:
$Env:PSModulePath
You can use the following command format:
$Env:PSModulePath = $Env:PSModulePath + ";<path>"
Use the following to execute the same command as above, only with Linux or macOS:
$Env:PSModulePath += ":<path>"
A hash table is a complex data structure to store data in the form of key-value pairs. We also refer to a hash table as a dictionary or associative array. To understand a hash table, consider a series of IP addresses and the respective computer names. A hash stores this data in the form of key-value pairs, where IP addresses refer to keys and computer names to their corresponding values.
The hash table syntax is as follows:@{ <name> = <value>; [<name> = <value> ] …}
An ordered dictionary’s syntax is as follows:[ordered]@{ <name> = <value>; [<name> = <value> ] …}
If you want to create a hash table, follow these steps:
For example:
$hash = @{}
$hash = @{ Number = 1; Shape = "Square"; Color = "Blue"}
[hashtable]$hash = [ordered]@{
Number = 1; Shape = "Square"; Color = "Blue"}
$hash
To add keys and values to a hash table, use the following command format:
$hash[“<key>”] = “<value>”
For example, you can add a “Time” key with a value of “Now” to the hash table with the following statement format:
$hash["Time"] = "Now"
Or
$hash.Add("Time", "Now")
Or, you can remove the key with this statement format:
$hash.Remove("Time")
These cmdlets allow you to register and unregister event subscriptions and list the existing subscriptions. You can also list pending events and handle or remove them as desired.
PowerShell eventing cmdlets
| Eventing Cmdlet name | Description |
| Register-ObjectEvent | This cmdlet registers an event subscription for events generated by .NET objects |
| Register-WmiEvent | Registers an event subscription for events generated by WMI objects |
| Register-EngineEvent | Registers an event subscription for events generated by PowerShell itself |
| Get-EventSubscriber | Gets a list of the registered event subscriptions in the session |
| Unregister-Event | Removes one or more of the registered event subscriptions |
| Wait-Event | Waits for an event to occur. This cmdlet can wait for a specific event or any event. It also allows a timeout to be specified, limiting how long it will wait for the event. The default is to wait forever. |
| Get-Event | Gets pending unhandled events from the event queue |
| Remove-Event | Removes a pending event from the event queue |
| New-Event | This cmdlet is called in a script to allow the script to add its own events to the event queue |
If you’re asked to enter your FTP credentials when you try to install or update a plugin or theme in the WordPress dashboard, it’s because of a specific setting in the wp-config.php file. Follow the steps below to prevent WordPress from displaying this FTP prompt.
wp-config.php file.wp-config.php file, above the line that says /* That's all, stop editing! Happy publishing. */,define('FS_METHOD', 'direct');
define('FS_CHMOD_DIR',0755);
define('FS_CHMOD_FILE',0644);
Let’s start by taking a look at a basic switch statement.
| $i = 1; |
| switch ($i) |
| { |
| 1 { |
| write-host “one” |
| break |
| } |
| 2 { |
| write-host “two” |
| write-host “two” |
| break |
| } |
| default { |
| write-host “other” |
| break |
| } |
| } |
Notice we don’t use the Case: keyword at all.
The default in PowerShell is to assume -eq is used between your input and typed case value. This means No Case Sensitivity and No Wild Cards:
| switch(“hello”) #will match uppercase |
| { |
| “HELLO” {write-host “Uppercase” -ForegroundColor Magenta;break} |
| “hello” {write-host “lowercase” -ForegroundColor green;break} |
| } |
| switch(“hello”) #will NOT match h* |
| { |
| “h*” {write-host “wildcard” -ForegroundColor Magenta;break} |
| “hello” {write-host “lowercase” -ForegroundColor green;break} |
| } |
We have a long-hand switch statement that lets us use whatever we want (-eq, -gt, -le, -like, straight up boolean values, etc.)
Psudo-code:Switch($value) { {<bool expression>} {<code>} {<bool expression>} {<code>} default {<code>} }
Real:
| switch(“hello”) #will match uppercase |
| { |
| “HELLO” {write-host “Uppercase” -ForegroundColor Magenta;break} |
| “hello” {write-host “lowercase” -ForegroundColor green;break} |
| } |
| switch(“hello”) #will NOT match h* |
| { |
| “h*” {write-host “wildcard” -ForegroundColor Magenta;break} |
| “hello” {write-host “lowercase” -ForegroundColor green;break} |
| } |
C# requires jump statements such as break, goto, or return. PowerShell does not!
This is one of the coolest features in PowerShell. We actually allow for continuous case- checks.
This means your switches can actually act more like a bunch of independent if statements. Notice the previous example, without any of the “break statements” and using a number that is less than 5, 10 and 15.
| $num = 4 | |
| Switch($num) | |
| { | |
| {$num -lt 5} {write-host “less than 5!” -ForegroundColor Magenta} | |
| {$num -lt 10} {write-host “less than 10!” -ForegroundColor green} | |
| {$num -lt 15} {write-host “less than 15!” -ForegroundColor cyan} | |
| default {write-host “greater than or equal to 15” -ForegroundColor yellow} | |
| } |
It might be common for you to take a bunch of data, do a foreach loop through it and send each value through your switch:
| $nums = 1..15 |
| foreach($num in $nums) |
| { |
| Switch($num) |
| { |
| {$num -lt 5} {write-host “$num is less than 5!” -ForegroundColor Magenta} |
| {$num -lt 10} {write-host “$num is less than 10!” -ForegroundColor green} |
| {$num -lt 15} {write-host “$num is less than 15!” -ForegroundColor cyan} |
| default {write-host “$num is greater than or equal to 15” -ForegroundColor yellow} |
| } |
| } |
However, PowerShell actually has a loop and $_ built right into your switch so we can chop off the foreach completely:
| $nums = 1..15 |
| Switch($nums) |
| { |
| {$_ -lt 5} {write-host “$_ is less than 5!” -ForegroundColor Magenta} |
| {$_ -lt 10} {write-host “$_ is less than 10!” -ForegroundColor green} |
| {$_ -lt 15} {write-host “$_ is less than 15!” -ForegroundColor cyan} |
| default {write-host “$_ is greater than or equal to 15” -ForegroundColor yellow} |
| } |
This lets us write some really concise and convenient little code blocks. The nice thing is that if our list has 1 object it still gets handled fine, and if it’s an empty collection it will just skip the whole switch!
This, however, can lead to some confusion if you try to use “break” since our loop is also the whole switch statement:
| $nums = 1..15 |
| Switch($nums) |
| { |
| {$_ -lt 5} {write-host “$_ is less than 5!” -ForegroundColor Magenta;break} |
| {$_ -lt 10} {write-host “$_ is less than 10!” -ForegroundColor green;break} |
| {$_ -lt 15} {write-host “$_ is less than 15!” -ForegroundColor cyan;break} |
| default {write-host “$_ is greater than or equal to 15” -ForegroundColor yellow} |
| } |
view rawLoopSwitchSample3.ps1 hosted with ❤ by GitHub
Uh-oh, not good.
We also have “continue” in PowerShell and this will stop our current iteration of our loop (or switch) so we can use the looping feature and make it like a bunch of elseifs:
| $nums = 1..15 |
| Switch($nums) |
| { |
| {$_ -lt 5} {write-host “$_ is less than 5!” -ForegroundColor Magenta;continue} |
| {$_ -lt 10} {write-host “$_ is less than 10!” -ForegroundColor green;continue} |
| {$_ -lt 15} {write-host “$_ is less than 15!” -ForegroundColor cyan;continue} |
| default {write-host “$_ is greater than or equal to 15” -ForegroundColor yellow} |
| } |
In addition to the looping, we provide you a few other handy short cuts.
If you just wanted a basic equality switch, but would want to use -ceq (case sensitivity), -like (wild cards), or -match (regex) we let you do that without writing an expression match via some parameters.
Notice, weirdly, the parameters must come between the word “switch” and the parenthesis, they won’t work at the end of the parenthesis.
| switch -casesensitive (“hello”) #makes it a -ceq |
| { |
| “HELLO” {write-host “Uppercase” -ForegroundColor Magenta} |
| “hello” {write-host “lowercase” -ForegroundColor green} |
| “h*” {write-host “wildcard” -ForegroundColor Magenta} |
| } |
| switch -wildcard (“hello”) #makes it a -like |
| { |
| “HELLO” {write-host “Uppercase” -ForegroundColor Magenta} |
| “hello” {write-host “lowercase” -ForegroundColor green} |
| “h*” {write-host “wildcard” -ForegroundColor Magenta} |
| } |
| switch -wildcard -CaseSensitive (“hello”) #makes it a -clike |
| { |
| “HELLO” {write-host “Uppercase” -ForegroundColor Magenta} |
| “hello” {write-host “lowercase” -ForegroundColor green} |
| “h*” {write-host “wildcard” -ForegroundColor Magenta} |
| } |
| switch -regex (“hello”) #makes it a -match |
| { |
| “\w{5}” {write-host “5 characters” -ForegroundColor Magenta} |
| “\w{6}” {write-host “6 characters” -ForegroundColor green} |
| } |
Get-AliasNew-AliasSet-AliasExport-AliasImport-Alias To see the definition of mkdir use
Get-Content Function:\mkdir
.Migration is done via azcopy:
Here is the script install-azcopy.ps1:
# Download and extract # $URI = "https://aka.ms/downloadazcopy-v10-windows" $DST = "~\AppData\Local\Programs\AZCopy\" Invoke-WebRequest -Uri $URI -OutFile AzCopy.zip -UseBasicParsing Expand-Archive ./AzCopy.zip ./AzCopy -Force # Move AzCopy mkdir ~\AppData\Local\Programs\AZCopy Get-ChildItem ./AzCopy/*/azcopy.exe | Move-Item -Destination "~\$DEST" # Add AzCopy to PATH $userenv = (Get-ItemProperty -Path 'HKCU:\Environment' -Name Path).path $newPath = "$userenv;%USERPROFILE%\$DEST;" New-ItemProperty -Path 'HKCU:\Environment' -Name Path -Value $newPath -Force # Clean the kitchen del -Force AzCopy.zip del -Force -Recurse .\AzCopy\
param (
$FOLDER = "",
[Parameter(Mandatory=$false)]
[string]$TYPE = "latest",
[Parameter(Mandatory=$false)]
[switch]$LOGIN
)
if ($TYPE -eq "latest") {
$SRC_ROOT="<latest-folder>"
$DST_ROOT="latest"
} else {
$SRC_ROOT="<history-folder>"
$DST_ROOT="history"
}
$SRC_ACCCOUNT = "<source storage account>";
$DST_ACCCOUNT = "<destination storage account>";
$SRC_CONTAINER = "<source container>"
$DST_CONTAINER = "<destination container>"
$SRC_URL = "https://${SRC_ACCCOUNT}.blob.core.windows.net/$SRC_CONTAINER/$SRC_ROOT/$FOLDER/"
$DST_URL = "https://${DST_ACCCOUNT}.blob.core.windows.net/$DST_CONTAINER/$DST_ROOT/"
$TMP_FLDR = "C:\TMP\Downloads"
Write-Host "== Copy '$FOLDER'"
Write-Host " from $SRC_URL"
Write-Host " to $DST_URL"
#
if ($LOGIN) {
$ENV:AZCOPY_CRED_TYPE = "OAuthToken";
$ENV:AZCOPY_CONCURRENCY_VALUE = "AUTO";
azcopy login
}
Write-Host "== Download ======================================================"
Write-Host " from $SRC_URL"
Write-Host " to $TMP_FLDR\$CONTAINER"
azcopy copy $SRC_URL `
$TMP_FLDR `
--trusted-microsoft-suffixes=${SRC_ACCCOUNT}.blob.core.windows.net `
--overwrite=true `
--check-md5=FailIfDifferent `
--from-to=BlobLocal `
--recursive `
--log-level=ERROR
# Upload
Write-Host "== Upload ======================================================"
Write-Host " from $TMP_FLDR\$CONTAINER"
Write-Host " to $DST_URL"
azcopy copy $TMP_FLDR\$CONTAINER `
$DST_URL `
--overwrite=true `
--from-to=LocalBlob `
--blob-type BlockBlob `
--follow-symlinks `
--check-length=true `
--put-md5 `
--follow-symlinks `
--disable-auto-decoding=false `
--recursive `
--log-level=ERROR
First call should use -login to authenticate
.\copy.ps1 demo-folder-1 -login
Then, following commands dont need the login
.\copy.ps1 demo-folder-2
Search post content.
wp post list --s="text" --fields=ID,post_title,url
Find posts with ping status “open”.
wp post list --ping_status="open"
And if you only want to get the post IDs:
wp post list --ping_status="open" --fields=ID
Update ping status to “closed” where the value is “open”.
wp post update $(wp post list --ping_status="open" --format=ids) --ping_status="closed";
Search and replace post content.
bashwp search-replace "old thing" "new thing" --all-tables
List all metadata associated with a post.
bashwp post meta list 1422 --format=json
Get specific post meta for a post.
bashwp post meta get 1422 "meta_key" --format=json
Update post meta.
bashwp post meta update 1422 "meta_key" "meta_value"
Update post meta from a file.
bashwp post meta update 1422 "post_meta" < file.json --format=json
Delete post meta.
bashwp post meta delete 1422 "post_meta"
Delete all post meta by specific key. (With wp db query.)
bashwp db query "DELETE FROM `wp_postmeta` WHERE `meta_key` = 'NAME_OF_YOUR_META_KEY'"
List posts by meta key or value.
bashwp post list --fields=ID,post_title,url --meta_key="meta_key" wp post list --fields=ID,post_title,url --meta_key="meta_key" --meta_compare="NOT EXISTS" wp post list --post_type="post_type" --fields=ID,post_title,url --meta_key="meta_key" --meta_compare="NOT EXISTS" wp post list --fields=ID,post_title,url --meta_key="_wp_page_template" --meta_value="page-templates/post-full-grid.php"
The meta_compare flag also accepts "LIKE" as a value, so that you can do:
phpwp post list --fields=ID,post_title,url --meta_key='meta_key' --meta_compare='LIKE' --meta_value='value'
Update meta where it’s missing.
bashwp post meta update $(wp post list --post_type="post_type" --meta_key="meta_key" --meta_compare="NOT EXISTS" --format=ids) "meta_key" "meta_value"
Update post meta for all posts in a category.
bashwp post meta update $(wp post list --category_name="category" --format=ids) "meta_key" "meta_value"
Save meta value based on an existing meta value. In this example I’m looping through all post with a specific post type and saving the URL of the featured image to the post’s meta.
bashfor id in $(wp post list --post_type="post_type" --fields=ID --meta_key="meta_key" --meta_compare="NOT EXISTS")
do
wp post meta update $id "meta_key" $(wp post meta pluck $(wp post meta get $id _thumbnail_id) _wp_attachment_metadata file)
done
Show specific meta value for posts based on a category.
bashfor id in $(wp post list --post_type="post_type" --fields=ID --category="category name")
do
wp post meta get $id "meta_key"
done
Export/import all meta.
bashwp post meta list 1422 --format=json > 1422_meta.json wp post update 1422 --meta_input= < 1422_meta.json
Move posts from one tag to another.
bashfor id in $(wp post list --tag=OLD_TAG --format=ids)
do
wp post term remove $id post_tag OLD_TAG --by=slug
wp post term add $id post_tag NEW_TAG --by=slug
done
Delete all posts from a custom post type. (Adding --force will skip the trash and remove the posts completely.)
bashwp post delete $(wp post list --post_type='activity' --format=ids) --force
If you’re trying to delete too many posts at once, you might get an error like this:
bashPHP Fatal error: Allowed memory size of xxx bytes exhausted
Or perhaps this one:
bashArgument list too long
One way around this is to limit how many posts you’re deleting at once using the posts_per_page option, for example:
bashwp post delete $(wp post list --post_type='activity' --posts_per_page=50000 --format=ids) --force
Delete posts with specific meta key.
bashwp post delete $(wp post list --format=ids --meta_key="meta_key")
Delete posts with specific meta key and meta value.
bashwp post delete $(wp post list --format=ids --meta_key="meta_key" --meta_value="meta_value")
Delete posts where a specific meta key is missing.
bashwp post delete $(wp post list --format=ids --meta_key="meta_key" --meta_compare="NOT EXISTS")
List all revisions.
bashwp post list --post_type=revision
List revisions for a specific post.
bashwp post list --post_parent=1422 --post_type=revision
Get more info on revisions for a specific post.
bashfor id in $(wp post list --post_parent=1422 --post_type=revision --fields=ID)
do
wp post get $id
done
Change the site URL.
bashwp option update home 'https://example.com' wp option update siteurl 'https://example.com'
List active plugins.
bashwp plugin list --status=active
Activate/deactivate plugins.
bashwp plugin activate plugin-1 plugin-2 plugin-3 wp plugin deactivate plugin-1 plugin-2 plugin-3
Update user password.
wp user update USER_ID --user_pass="newpassword"
Returns sizes of all database tables in a human friendly format.
Reference:https://developer.wordpress.org/cli/commands/db/size/
wp db size --human-readable --tables
copy
Run health check on the database set in the wp-config.php file. It reports status of each database table separately in the output.
Reference:https://developer.wordpress.org/cli/commands/db/check/
wp db check
copy
Checks if WP-CLI is due for an update.
wp cli check-update
copy
Return WP CLI version.
wp cli version
copy
Creates config.php file. Requires mysql cli to be installed.
wp config create --dbname=yourdbname --dbuser=root --prompt=dbpassword
copy
This command searches for all posts in the database and returns the count number.
Reference:https://developer.wordpress.org/cli/commands/post/list/
wp post list --format=count
copy
Download latest version of WordPress core files to current directory.
wp core download
copy
Opens wp-config.php file in the default text editor.
wp config edit
copy
Exports WXR file containing XML formatted data about your site including posts, comments and information about images and other attachments. Site option settings are excluded.
Reference:https://developer.wordpress.org/cli/commands/export/
wp export
copy
By combining the following flags you can export a single page from WordPress. First set the post type you want to export (page) then set the ID of the post, and finally limit the command to only fetch a single post. Skipping comments is optional.
Reference:https://developer.wordpress.org/cli/commands/export/
wp export --skip_comments --post_type=page --post__in=4995 --max_num_posts=1
copy
This command will generate authentication unique keys and salts in your wp-config.php file.
Reference:https://developer.wordpress.org/cli/commands/config/shuffle-salts/
wp config shuffle-salts
copy
List all defined image sizes, their width, height and the crop details.
Reference:https://developer.wordpress.org/cli/commands/media/image-size/
wp media image-size
copy
Imports WXR files.
Reference:https://developer.wordpress.org/cli/commands/import/
wp import yoursiteexample.wordpress.2021-09-22.000.xml
copy
You can import WXR data files to specific site in the multi-site installation. The –url flag identifies the site you want to migrate data to. Skipping authors is optional.
Reference:https://developer.wordpress.org/cli/commands/import/
wp import yoursiteexample.wordpress.2021-10-15.000.xml --authors=skip --url=http://yoursite.com/subsite
copy
Install a plugin in your WordPress site. By passing –activate flag you can enable your new plugin in one command.
wp plugin install [pluginhandle] --activate
copy
This command is based on the “wp post list” used to return all posts but the “–post_type=page” flag changes the search scope to return only pages. By default the output if formatted as a table and includes page ID, title, slug, creation date, and the status.
Reference:https://developer.wordpress.org/cli/commands/post/list/
wp post list --post_type=page
copy
Use post ID to return all related meta data. By default it returns data as a table but other formats are available, for example you can use this flag –format=json to get data as json.
Reference:https://developer.wordpress.org/cli/commands/post/meta/list/
wp post meta list <ID>
copy
Returns a table of custom posts with a type specified using the –post_type flag.
Reference:https://developer.wordpress.org/cli/commands/post/list/
wp post list --post_type=movie
copy
Lists all columns in a given database table. You will need to pass a table name as the argument. List of the default WordPress tables – wp_commentmeta, wp_comments, wp_links, wp_options, wp_postmeta, wp_posts, wp_term_relationships, wp_term_taxonomy, wp_termmeta, wp_terms, wp_usermeta, wp_users.
Reference:https://developer.wordpress.org/cli/commands/db/columns/
wp db columns {tabel name}
copy
Lists all tables in the database connected to your site.
Reference:https://developer.wordpress.org/cli/commands/db/tables/
wp db tables
copy
Returns a table of all post types including custom posts.
Reference:https://developer.wordpress.org/cli/commands/post-type/
wp post-type list
copy
Returns a table of all posts including ID, title, name, date and status.
Reference:https://developer.wordpress.org/cli/commands/post/list/
wp post list
copy
If you’re running a multi-site WordPress installation you can return a handy table presenting blog ID, URL, and update dates of each site instance.
Reference:https://developer.wordpress.org/cli/commands/site/list/
wp site list
copy
Returns a table of all registered taxonomies including categories, post tags, navigation menus, themes, custom taxonomies and more.
Reference:https://developer.wordpress.org/cli/commands/taxonomy/list/
wp taxonomy list
copy
Puts your site in a maintenance mode and returns “Briefly unavailable for scheduled maintenance. Check back in a minute.” message with a 503 server response.
wp maintenance-mode activate
copy
Takes your site out of maintenance mode.
wp maintenance-mode deactivate
copy
Returns maintenance mode status of your site.
wp maintenance-mode status
Connects to the database set in your wp-config.php file using MySQL CLI.
Reference:https://developer.wordpress.org/cli/commands/db/cli/
wp db cli
Runs MySQL optimizer on the connected database.
Reference:https://developer.wordpress.org/cli/commands/db/optimize/
wp db optimize
Regenerate all thumbnail image sizes stored in the media library. The –yes flag confirms your choice.
wp media regenerate --yes
copy
This command will generate basic files and structure for a new plugin. Use –skip-tests flag to omit php unit tests in the process.
Reference:https://developer.wordpress.org/cli/commands/scaffold/plugin/
wp scaffold plugin your-plugin-slug
copy
Generates un-styled main theme with all the necessary files and views to display content.
Reference:https://developer.wordpress.org/cli/commands/scaffold/_s/
wp scaffold _s your-theme-slug --theme_name="Theme Name" --author="Your Name"
copy
You can search for a string in connected WordPress database. The –stats flag will append details about the search like matches found and tables searched.
Reference:https://developer.wordpress.org/cli/commands/db/search/
wp db search <string_to_find> --stats
Updates all installed plugins.
wp plugin update --all
Update WP-CLI to the latest version.
wp cli update
Prints information to the console about WP CLI and its environment such as version, OS, PHP, MySQL.
brew install jq
When running jq, the following arguments may become handy:
| Argument | Description |
|---|---|
--version | Output the jq version and exit with zero. |
--sort-keys | Output the fields of each object with the keys in sorted order. |
The syntax for jq is pretty coherent:
| Syntax | Description |
|---|---|
| , | Filters separated by a comma will produce multiple independent outputs |
| ? | Will ignores error if the type is unexpected |
| [] | Array construction |
| {} | Object construction |
| + | Concatenate or Add |
| – | Difference of sets or Substract |
| length | Size of selected element |
| | | Pipes are used to chain commands in a similar fashion than bash |
| Description | Command |
|---|---|
| Display all keys | jq 'keys' |
| Adds + 1 to all items | jq 'map_values(.+1)' |
| Delete a key | jq 'del(.foo)' |
| Convert an object to array | to_entries | map([.key, .value]) |
| Description | Command |
|---|---|
| Concatenate two fields | fieldNew=.field1+' '+.field2 |
| Description | Command |
|---|---|
| All | jq .[] |
| First | jq '.[0]' |
| Range | jq '.[2:4]' |
| First 3 | jq '.[:3]' |
| Last 2 | jq '.[-2:]' |
| Before Last | jq '.[-2]' |
| Select array of int by value | jq 'map(select(. >= 2))' |
| Select array of objects by value | ** jq ‘.[] | select(.id == “second”)’** |
| Select by type | ** jq ‘.[] | numbers’ ** with type been arrays, objects, iterables, booleans, numbers, normals, finites, strings, nulls, values, scalars |
| Description | Command |
|---|---|
| Add + 1 to all items | jq 'map(.+1)' |
| Delete 2 items | jq 'del(.[1, 2])' |
| Concatenate arrays | jq 'add' |
| Flatten an array | jq 'flatten' |
| Create a range of numbers | jq '[range(2;4)]' |
| Display the type of each item | jq 'map(type)' |
| Sort an array of basic type | jq 'sort' |
| Sort an array of objects | jq 'sort_by(.foo)' |
| Group by a key – opposite to flatten | jq 'group_by(.foo)' |
| Minimun value of an array | jq 'min' .See also min, max, min_by(path_exp), max_by(path_exp) |
| Remove duplicates | jq 'unique' or jq 'unique_by(.foo)' or jq 'unique_by(length)' |
| Reverse an array | jq 'reverse' |