Mastering PowerShell: The Most Powerful Commands You Need to Know

PowerShell is a powerful task automation and configuration management framework developed by Microsoft. It has become an indispensable tool for system administrators, developers, and power users alike. With its extensive command set and scripting capabilities, PowerShell can automate virtually any task on Windows, from simple file operations to complex network configurations.

In this blog post, we'll dive into some of the most powerful PowerShell commands that you should have in your toolkit. Whether you're a seasoned administrator or just starting out, these commands will help you streamline your workflow and get things done efficiently.

1. Get-Command

The Get-Command cmdlet is your go-to command for discovering what's available in PowerShell. It retrieves all the commands that are available in the current session, including cmdlets, functions, scripts, and more.

Use Case: When you're not sure which command to use for a particular task, Get-Command can help you find the right one.

Get-Command -Name *process*

This command will list all commands related to processes, such as Get-Process, Stop-Process, etc.

2. Get-Process and Stop-Process

These cmdlets are essential for managing running processes on your system.

Use Case: You can use Get-Process to list all running processes and Stop-Process to terminate a process that's causing issues.

# Get a list of all running processes
Get-Process

# Stop a process by name
Stop-Process -Name notepad

3. Get-Service and Set-Service

These cmdlets allow you to manage services on your machine.

Use Case: You can use Get-Service to check the status of a service and Set-Service to start, stop, or restart it.

# Get the status of a specific service
Get-Service -Name spooler

# Stop a service
Set-Service -Name spooler -Status Stopped

# Start a service
Set-Service -Name spooler -Status Running

4. Get-Content and Set-Content

These cmdlets are used for reading from and writing to files.

Use Case: You can use Get-Content to read the contents of a file and Set-Content to write data to a file.

# Read the contents of a file
Get-Content -Path "C:\path\to\file.txt"

# Write content to a file
Set-Content -Path "C:\path\to\file.txt" -Value "Hello, PowerShell!"

5. Get-ChildItem and Remove-Item

These cmdlets are used for listing and removing items in a directory.

Use Case: Get-ChildItem can be used to list files and directories, while Remove-Item can be used to delete them.

# List all items in a directory
Get-ChildItem -Path "C:\path\to\directory"

# Remove a file
Remove-Item -Path "C:\path\to\file.txt"

# Remove a directory and its contents
Remove-Item -Path "C:\path\to\directory" -Recurse

6. Invoke-WebRequest

This cmdlet allows you to download files or content from the web.

Use Case: You can use Invoke-WebRequest to download files, scripts, or even web pages.

# Download a file from the web
Invoke-WebRequest -Uri "https://example.com/file.zip" -OutFile "C:\path\to\file.zip"

7. Get-NetTCPConnection

This cmdlet provides detailed information about active TCP connections.

Use Case: You can use Get-NetTCPConnection to monitor network traffic and diagnose connectivity issues.

# Get all active TCP connections
Get-NetTCPConnection

# Get connections to a specific port
Get-NetTCPConnection -LocalPort 80

8. Test-Connection

This cmdlet is similar to the ping command in DOS, but with more features.

Use Case: You can use Test-Connection to test the reachability of a host and diagnose network issues.

# Test connection to a host
Test-Connection -ComputerName "google.com" -Count 4

9. Set-ExecutionPolicy

This cmdlet is used to set the execution policy for scripts in PowerShell.

Use Case: You might need to change the execution policy to run scripts that are signed or unsigned.

# Set the execution policy to RemoteSigned
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned

10. Get-ScheduledTask and Register-ScheduledTask

These cmdlets are used for managing scheduled tasks.

Use Case: You can use these cmdlets to view, create, or modify scheduled tasks on your system.

# Get all scheduled tasks
Get-ScheduledTask

# Register a new scheduled task
Register-ScheduledTask -Action (New-ScheduledTaskAction -Execute 'notepad.exe') -Trigger (New-ScheduledTaskTrigger -At 9am) -TaskName 'OpenNotepad'

11. Invoke-Command

This cmdlet allows you to run commands on remote computers.

Use Case: You can use Invoke-Command to execute scripts or commands on multiple remote machines.

# Run a command on a remote computer
Invoke-Command -ComputerName "RemotePC" -ScriptBlock { Get-Process }

# Run a command on multiple remote computers
Invoke-Command -ComputerName "RemotePC1", "RemotePC2" -ScriptBlock { Get-Service -Name spooler }

12. Get-EventLog and Clear-EventLog

These cmdlets are used for managing event logs.

Use Case: You can use Get-EventLog to view event logs and Clear-EventLog to clear them.

# Get entries from the System event log
Get-EventLog -LogName System

# Clear the System event log
Clear-EventLog -LogName System

13. Get-ADUser and Set-ADUser

These cmdlets are part of the ActiveDirectory module and are used for managing Active Directory users.

Use Case: You can use these cmdlets to retrieve user information and modify user properties.

# Get information about a specific user
Get-ADUser -Identity "username"

# Set a new password for a user
Set-ADUser -Identity "username" -PasswordNeverExpires $true

14. Set-Location and Get-Location

These cmdlets are used for navigating the file system.

Use Case: You can use Set-Location to change directories and Get-Location to check your current location.

# Change directory
Set-Location -Path "C:\path\to\directory"

# Get current directory
Get-Location

Conclusion

PowerShell is a versatile tool that can greatly enhance your productivity, whether you're managing a single machine or an entire network. The commands discussed in this post are just the tip of the iceberg, but they provide a solid foundation for tackling a wide range of tasks.

As you become more comfortable with PowerShell, you'll find that there's almost no limit to what you can automate and manage using this powerful framework. So, keep exploring, keep experimenting, and most importantly, keep scripting!