PowerShell: Meet PowerShell

In one line: the engine runs your commands; the host (console, Windows Terminal, VS Code) is the window — set up a readable console, master Tab and PSReadLine, and elevate only when you need to.

Companion to: Learn PowerShell in a Month of Lunches (Jeffery Hicks et al.), Chapter 2. The full version is the Chapter 2 class notes.

Engine vs host

$Host.Name tells you which host you’re in — ConsoleHost in a terminal, Visual Studio Code Host in VS Code.

Where to work

Host	Best for
Console (Windows Terminal)	Interactive commands — most of this book
VS Code + PowerShell extension	Writing/debugging scripts. F8 runs a selection, F5 runs the file
ISE	Legacy, Windows PowerShell 5.1 only — not PS7

Console setup

Monospaced coding font (distinguishes backtick ` from apostrophe '), readable size, high-contrast colours, wide window.

Typing faster

Feature	Key
Tab completion	Tab — commands, parameters, values, paths
Show all matches	Ctrl+Space (Windows)
History search	Ctrl+R, type part of an old command
Accept a prediction	Right arrow (grey suggested text)
Switch prediction view	F2

Get-History = this session only. The PSReadLine file = every session, saved to disk:

(Get-PSReadLineOption).HistorySavePath

Running elevated

Platform	How	How to tell
Windows	Right-click → Run as administrator	Title bar starts “Administrator:”
macOS/Linux	`sudo <command>`	Password prompt

([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole(
    [Security.Principal.WindowsBuiltInRole]::Administrator)

Cross-platform gotchas

Windows	Linux/macOS
`\` paths (also accepts `/`)	`/` paths
Not case-sensitive filenames	Case-sensitive
`ls`, `cat`, `ps` are aliases for cmdlets	Those names run the native commands instead

🔐 Security notes

The PSReadLine history file is plain text and persists across sessions — never type secrets as command arguments; use Get-Credential instead.
Elevate only for the task, then close the elevated window — don’t explore day-to-day as admin.
Start-Transcript / Stop-Transcript records a session for change evidence — but store transcripts carefully, since they can capture sensitive output.

Practice drills

1. How do you find out which host you're running in?

$Host.Name.

2. In VS Code, what's the difference between F8 and F5?

F8 runs the current line/selection; F5 runs the whole script.

3. How do you search backwards through command history for one containing "Sort-Object"?

Press Ctrl+R, then type Sort-Object.

4. What's the difference between Get-History and the PSReadLine history file?

Get-History covers only the current session; the PSReadLine file covers every session, saved to disk.

5. Why does `ls -la` work on Linux PowerShell but not on Windows PowerShell?

On Linux, ls isn’t a PS alias, so it runs the native ls; on Windows, ls is an alias for Get-ChildItem, which has no -la parameter.

Key takeaways

Engine runs commands; host (console, VS Code, ISE) displays them. Check with $Host.Name.
Console for interactive work; VS Code + PowerShell extension for scripts (F8/F5); ISE is 5.1-only.
Tab completes; PSReadLine adds Ctrl+R search and grey predictions (Right arrow to accept).
Elevate on Windows via “Run as administrator” (title bar tells you); sudo elsewhere.
Paths and case sensitivity, and some aliases, differ between Windows and Linux/macOS.