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## PowerShell Cheatsheet

### Overview

PowerShell is a cross-platform, object-oriented scripting language and command-line shell created by Microsoft. It is designed for system administrators and developers to automate tasks and manage configurations across Windows, Linux, and macOS.

### Variables

PowerShell variables are prefixed with a `


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 symbol and can store a variety of data types, including strings, integers, arrays, and objects.

String variable

$name = "Alice"

Integer variable

$age = 30

Array variable

$numbers = @(1, 2, 3, 4, 5)

Object variable

$person = @{

Name = "Bob"

Age = 40

}


### Functions

PowerShell has a large number of built-in cmdlets (pronounced "command-lets") for common tasks such as string manipulation, file I/O, and process management. Cmdlets are called using a verb-noun syntax.

String manipulation

$name = "Alice"

$length = $name.Length # Returns 5

File I/O

Get-Content -Path "input.txt"

Process management

Get-Process | Where-Object {$_.Name -eq "notepad"}


### Loops

PowerShell has several types of loops, including `for`, `foreach`, `while`, and `do-while`. The `for` and `foreach` loops are used to iterate over arrays or lists, while the `while` and `do-while` loops are used to repeat a block of code while a condition is true or false, respectively.

For loop

for ($i = 0; $i -lt 10; $i++) {

Write-Output $i

}

Foreach loop

$numbers = @(1, 2, 3, 4, 5)

foreach ($num in $numbers) {

Write-Output $num

}

While loop

$i = 0

while ($i -lt 10) {

Write-Output $i

$i++

}

Do-while loop

$i = 0

do {

Write-Output $i

$i++

} while ($i -lt 10)


### Conditionals

PowerShell has several conditional statements, including `if`, `elseif`, `else`, and `switch`. These statements are used to control the flow of a program based on certain conditions.

If statement

$age = 30

if ($age -ge 18) {

Write-Output "You are an adult"

}

If-else statement

$age = 15

if ($age -ge 18) {

Write-Output "You are an adult"

} else {

Write-Output "You are a minor"

}

If-elseif-else statement

$age = 25

if ($age -lt 18) {

Write-Output "You are a minor"

} elseif ($age -lt 65) {

Write-Output "You are an adult"

} else {

Write-Output "You are a senior"

}

Switch statement

$fruit = "apple"

switch ($fruit) {

"apple" {

Write-Output "It's an apple"

}

"banana" {

Write-Output "It's a banana"

}

default {

Write-Output "It's something else"

}


### File Manipulation

PowerShell provides several cmdlets for manipulating files, including `Get-Content`, `Set-Content`, `Rename-Item`, and `Remove-Item`.

Read file contents

Get-Content -Path "input.txt"

Write to file

Set-Content -Path "output.txt" -Value "Hello, world!"

Rename file

Rename-Item -Path "input.txt" -NewName "input.old"

Remove file

Remove-Item -Path "output.txt"


### Resources

- [PowerShell documentation](https://docs.microsoft.com/en-us/powershell/)
- [PowerShell on GitHub](https://github.com/PowerShell/PowerShell) (source code)
- [PowerShell Gallery](https://www.powershellgallery.com/) (community repository)
- [Learn PowerShell in Y minutes](https://learnxinyminutes.com/docs/powershell/) (quick reference guide)