PowerShell: Common Commands Reference

Table of Contents

• PowerShell Usages
• Active Directory Operations
  • Lookup User Information
  • Group Management
• File System Operations
  • Navigation and Listing
  • File Operations
  • Reading and Writing Files
• Process Management
  • Working with Processes
• Service Management
  • Service Operations
• Network Operations
  • Network Information
  • Download Files
• String Manipulation
  • Common String Operations
• Working with Arrays and Collections
  • Array Operations
  • Hash Tables
• Pipeline and Filtering
  • Using the Pipeline
• Error Handling
  • Try-Catch-Finally
• Remoting
  • Remote Execution
• Environment Variables
  • Working with Environment Variables
• Registry Operations
  • Working with Registry
• Scheduled Tasks
  • Task Management
• Useful Tips
  • Aliases
  • Getting Help
  • Execution Policy
• Resources

PowerShell Usages

Common PowerShell commands and patterns for system administration and automation on Windows.

Active Directory Operations

Lookup User Information

Query Active Directory for user details:

Get-ADUser -Server localhost -Identity cs -Properties *

Get specific properties:

Get-ADUser -Identity cs -Properties DisplayName, EmailAddress, Department

Search for users by name:

Get-ADUser -Filter "Name -like '*John*'" -Properties DisplayName, EmailAddress

Group Management

List user’s group memberships:

Get-ADPrincipalGroupMembership -Identity cs | Select-Object Name

Add user to group:

Add-ADGroupMember -Identity "Developers" -Members cs

Remove user from group:

Remove-ADGroupMember -Identity "Developers" -Members cs -Confirm:$false

File System Operations

Navigation and Listing

# Change directory
Set-Location C:\Users

# List files
Get-ChildItem

# List with details
Get-ChildItem | Format-Table Name, Length, LastWriteTime

# Recursive search
Get-ChildItem -Recurse -Filter "*.log"

File Operations

# Copy files
Copy-Item source.txt destination.txt

# Move files
Move-Item oldname.txt newname.txt

# Delete files
Remove-Item file.txt

# Create directory
New-Item -ItemType Directory -Path C:\NewFolder

Reading and Writing Files

# Read file content
Get-Content file.txt

# Write to file
"Hello World" | Out-File file.txt

# Append to file
"New line" | Add-Content file.txt

# Read as single string
Get-Content file.txt -Raw

Process Management

Working with Processes

# List running processes
Get-Process

# Filter by name
Get-Process -Name notepad

# Stop process
Stop-Process -Name notepad

# Start process
Start-Process notepad.exe

# Get process by ID
Get-Process -Id 1234

Service Management

Service Operations

# List all services
Get-Service

# Get specific service
Get-Service -Name wuauserv

# Start service
Start-Service -Name wuauserv

# Stop service
Stop-Service -Name wuauserv

# Restart service
Restart-Service -Name wuauserv

# Set service startup type
Set-Service -Name wuauserv -StartupType Automatic

Network Operations

Network Information

# Get IP configuration
Get-NetIPConfiguration

# Test connection
Test-Connection google.com

# Get network adapters
Get-NetAdapter

# DNS lookup
Resolve-DnsName google.com

Download Files

# Download file
Invoke-WebRequest -Uri "https://example.com/file.zip" -OutFile "file.zip"

# Download and execute script
Invoke-Expression (Invoke-WebRequest -Uri "https://example.com/script.ps1").Content

String Manipulation

Common String Operations

# String length
$str = "Hello World"
$str.Length

# Substring
$str.Substring(0, 5)  # "Hello"

# Replace
$str.Replace("World", "PowerShell")

# Split
$str.Split(" ")

# Join
$words = @("Hello", "World")
$words -join " "

# Case conversion
$str.ToUpper()
$str.ToLower()

Working with Arrays and Collections

Array Operations

# Create array
$arr = @(1, 2, 3, 4, 5)

# Access elements
$arr[0]

# Add elements
$arr += 6

# Filter array
$arr | Where-Object { $_ -gt 3 }

# Transform array
$arr | ForEach-Object { $_ * 2 }

# Sort array
$arr | Sort-Object -Descending

Hash Tables

# Create hash table
$hash = @{
    Name = "John"
    Age = 30
    City = "New York"
}

# Access values
$hash["Name"]
$hash.Age

# Add key-value pair
$hash["Email"] = "john@example.com"

# Remove key
$hash.Remove("City")

Pipeline and Filtering

Using the Pipeline

# Basic pipeline
Get-Process | Where-Object { $_.CPU -gt 100 } | Sort-Object CPU -Descending

# Select specific properties
Get-Service | Select-Object Name, Status

# Group by property
Get-Process | Group-Object ProcessName

# Measure objects
Get-ChildItem | Measure-Object -Property Length -Sum

Error Handling

Try-Catch-Finally

try {
    Get-Item "C:\nonexistent.txt" -ErrorAction Stop
}
catch {
    Write-Host "Error: $($_.Exception.Message)"
}
finally {
    Write-Host "Cleanup operations"
}

Remoting

Remote Execution

# Execute command on remote machine
Invoke-Command -ComputerName Server01 -ScriptBlock { Get-Process }

# Start interactive session
Enter-PSSession -ComputerName Server01

# Execute script on remote machine
Invoke-Command -ComputerName Server01 -FilePath C:\Scripts\script.ps1

# Copy to remote session
Copy-Item -Path C:\local\file.txt -Destination C:\remote\ -ToSession $session

Environment Variables

Working with Environment Variables

# Get environment variable
$env:PATH

# Set environment variable (current session)
$env:MY_VAR = "value"

# Set permanently (user)
[Environment]::SetEnvironmentVariable("MY_VAR", "value", "User")

# Set permanently (machine)
[Environment]::SetEnvironmentVariable("MY_VAR", "value", "Machine")

Registry Operations

Working with Registry

# Read registry value
Get-ItemProperty -Path "HKLM:\Software\Microsoft\Windows\CurrentVersion" -Name ProgramFilesDir

# Set registry value
Set-ItemProperty -Path "HKCU:\Software\MyApp" -Name "Setting" -Value "Value"

# Create registry key
New-Item -Path "HKCU:\Software\MyApp"

# Delete registry key
Remove-Item -Path "HKCU:\Software\MyApp"

Scheduled Tasks

Task Management

# List scheduled tasks
Get-ScheduledTask

# Create scheduled task
$action = New-ScheduledTaskAction -Execute "powershell.exe" -Argument "-File C:\script.ps1"
$trigger = New-ScheduledTaskTrigger -Daily -At 9am
Register-ScheduledTask -TaskName "MyTask" -Action $action -Trigger $trigger

# Run task
Start-ScheduledTask -TaskName "MyTask"

# Disable task
Disable-ScheduledTask -TaskName "MyTask"

Useful Tips

Aliases

# List all aliases
Get-Alias

# Common aliases
# ls -> Get-ChildItem
# cd -> Set-Location
# cat -> Get-Content
# rm -> Remove-Item
# cp -> Copy-Item
# mv -> Move-Item

Getting Help

# Get help for command
Get-Help Get-Process

# Get examples
Get-Help Get-Process -Examples

# Get detailed help
Get-Help Get-Process -Detailed

# Update help files
Update-Help

Execution Policy

# Check current execution policy
Get-ExecutionPolicy

# Set execution policy (run as administrator)
Set-ExecutionPolicy RemoteSigned

# Bypass for single script
PowerShell.exe -ExecutionPolicy Bypass -File script.ps1

Resources

• PowerShell Documentation
• PowerShell Gallery
• SS64 PowerShell Reference