The Philosophy of PowerShell.

Part 0.

What came before PowerShell? In 1981, MS-DOS 1.0 was released with the COMMAND.COM command interpreter. For task automation, batch files (.bat) were used—simple text files with a sequence of console commands. This was a surprising level of command-line asceticism compared to POSIX-compatible systems, where the Bourne shell (sh) had existed since 1979.

📅 State of the Shell Market at the Time of MS-DOS 1.0’s Release (August 1981)

Here is a summary table of popular OSes of that time and their shell support (sh, csh, etc.):

Operating System	Shell Support (sh, csh, etc.)	Comment
UNIX Version 7 (V7)	sh	The last classic UNIX from Bell Labs, widely used
UNIX/32V	sh, csh	UNIX version for the VAX architecture
4BSD / 3BSD	sh, csh	University branch of UNIX from Berkeley
UNIX System III	sh	The first commercial version from AT&T, predecessor to System V
Xenix (from Microsoft)	sh	A licensed version of UNIX, sold by Microsoft since 1980
IDRIS	sh	A UNIX-like OS for PDP-11 and Intel
Coherent (Mark Williams)	sh (similar)	An inexpensive UNIX alternative for PCs
CP/M (Digital Research)	❌ (No sh, only a very basic CLI)	Not UNIX, the most popular OS for 8-bit PCs
MS-DOS 1.0	❌ (only COMMAND.COM)	Minimal command shell, no scripts or pipes

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💡 What are sh, csh

• sh — Bourne Shell, the primary scripting interpreter for UNIX since 1977.
• csh — C Shell, an improved shell with C-like syntax and conveniences for interactive work.
• These shells supported redirects, pipes, variables, functions, and conditions—everything that made UNIX a powerful automation tool.

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Microsoft targeted cheap 16-bit IBM PCs, which had little memory (usually 64–256 KB), no multitasking, and were intended for home and office use, not servers. UNIX was expensive, required a complex architecture and expertise, while accountants and engineers, not system administrators, needed a fast and simple OS.

Instead of the complex sh, the DOS interface provided a single file, command.com, with a meager set of internal commands [ (dir, copy, del, etc.)](dir, copy, del, etc.) without functions, loops, or modules.

There were also external commands—separate executable files (.exe or .com). Examples: FORMAT.COM, XCOPY.EXE, CHKDSK.EXE, EDIT.COM. Execution scripts were written in a text file with the .bat (batch file) extension.

Examples of configuration files:

• AUTOEXEC.BAT

:: ------------------------------------------------------------------------------
:: AUTOEXEC.BAT — Automatic configuration and startup of Windows 3.11
:: Author: hypo69
:: Year: approximately 1993
:: Purpose: Initializes the DOS environment, loads network drivers, and starts Windows 3.11
:: ------------------------------------------------------------------------------
@ECHO OFF

:: Set the command prompt
PROMPT $p$g

:: Set environment variables
SET TEMP=C:\TEMP
PATH=C:\DOS;C:\WINDOWS

:: Load drivers and utilities into high memory
LH C:\DOS\SMARTDRV.EXE       :: Disk cache
LH C:\DOS\MOUSE.COM          :: Mouse driver

:: Load network services (relevant for Windows for Workgroups 3.11)
IF EXIST C:\NET\NET.EXE LH C:\NET\NET START

:: Automatically start Windows
WIN

• CONFIG.SYS

:: ------------------------------------------------------------------------------
:: CONFIG.SYS — DOS memory and driver configuration for Windows 3.11
:: Author: hypo69
:: Year: approximately 1993
:: Purpose: Initializes memory drivers, configures system parameters
:: ------------------------------------------------------------------------------
DEVICE=C:\DOS\HIMEM.SYS
DEVICE=C:\DOS\EMM386.EXE NOEMS
DOS=HIGH,UMB
FILES=40
BUFFERS=30
DEVICEHIGH=C:\DOS\SETVER.EXE

In parallel with DOS, Microsoft almost immediately began developing a fundamentally new kernel.

The Windows NT (New Technology) kernel first appeared with the release of the operating system:

Windows NT 3.1 — July 27, 1993

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• Development began: in 1988 under the leadership of Dave Cutler (a former DEC engineer and creator of VMS) with the goal of creating a completely new, secure, portable, and multitasking OS, not compatible with MS-DOS at the kernel level.
• NT 3.1 — was named to emphasize compatibility with Windows 3.1 at the interface level, but it was a completely new architecture.

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🧠 What the NT kernel brought:

Feature	Description
32-bit architecture	Unlike MS-DOS and Windows 3.x, which were 16-bit.
Multitasking	True preemptive multitasking.
Protected memory	Programs could not corrupt each other’s memory.
Modularity	Multi-layered kernel architecture: HAL, Executive, Kernel, drivers.
Multi-platform support	NT 3.1 ran on x86, MIPS, and Alpha.
POSIX compatibility	NT came with a POSIX subsystem, certified to POSIX.1.

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📜 The NT Lineage:

NT Version	Year	Comment
NT 3.1	1993	First NT release
NT 3.5 / 3.51	1994–1995	Improvements, optimization
NT 4.0	1996	Windows 95 interface, but NT kernel
Windows 2000	2000	NT 5.0
Windows XP	2001	NT 5.1
Windows Vista	2007	NT 6.0
Windows 10	2015	NT 10.0
Windows 11	2021	Also NT 10.0 (marketing 😊)

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Difference in operating system capabilities:

Characteristic	MS-DOS (1981)	Windows NT (1993)
System type	Monolithic, single-tasking	Microkernel/hybrid, multitasking
Bitness	16-bit	32-bit (with 64-bit support since NT 5.2 / XP x64)
Multitasking	❌ Absent (one process at a time)	✅ Preemptive multitasking
Protected memory	❌ No	✅ Yes (each process in its own address space)
Multi-user mode	❌ No	✅ Partially (in NT Workstation/Server)
POSIX compatibility	❌ No	✅ Built-in POSIX subsystem in NT 3.1–5.2
Kernel portability	❌ x86 only	✅ x86, MIPS, Alpha, PowerPC
Drivers	Direct hardware access	Through HAL and Kernel-mode Drivers
Application access level	Applications = system level	User / Kernel level separated
Security	❌ Absent	✅ Security model: SID, ACL, access tokens
Stability	❌ Dependency of one program = OS crash	✅ Process isolation, kernel protection

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But there was one big BUT! Automation and administration tools were not given due attention until 2002.

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Microsoft used completely different approaches, strategies, and tools for administration. All of this was disparate, often GUI-oriented, and not always automatable.

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📌 List of some tools:

Tool	Purpose
cmd.exe	Improved command interpreter (replacement for COMMAND.COM)
.bat, .cmd	Command-line scripts
Windows Script Host (WSH)	Support for VBScript and JScript for automation
reg.exe	Manage the registry from the command line
net.exe	Work with users, network, printers
sc.exe	Manage services
tasklist, taskkill	Manage processes
gpedit.msc	Group Policy (local)
MMC	Console with snap-ins for management
WMI	Access system information (via wmic, VBScript, or COM)
WbemTest.exe	GUI for testing WMI queries
eventvwr	View event logs
perfmon	Monitor resources

🛠 Automation examples:

• VBScript files (*.vbs) for administering users, networks, printers, and services.
• WMIC — command-line interface to WMI (e.g.: wmic process list brief).
• .cmd scripts with calls to net, sc, reg, wmic, etc.

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⚙️ Windows Scripting Host (WSH)

• First appeared in Windows 98, actively used in Windows 2000 and XP.
• Allowed running VBScript and JScript files from the command line:

  Set objShell = WScript.CreateObject("WScript.Shell")
  objShell.Run "notepad.exe"

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Part 1.

Only in 2002 did the company formulate the Monad project, which later evolved into PowerShell:

Start of development: approximately 2002

Public announcement: 2003, as “Monad Shell”

First beta versions: appeared by 2005

Final release (PowerShell 1.0): November 2006

The author and chief architect of the Monad / PowerShell project is Jeffrey Snover (Jeffrey Snover)

Today PowerShell Core runs on Windows macOS Linux

In parallel, the .NET framework was being developed, and PowerShell was deeply integrated into it. In the following chapters, I will show examples.

And now — the most important thing!

The main advantage of PowerShell compared to classic command shells is that it works with objects, not text. When you execute a command, it returns not just text, but a structured object (or a collection of objects) with clearly defined properties and methods.

See how PowerShell surpasses classic shells thanks to working with objects

📁 The old way: dir and manual parsing

In CMD (both in the old COMMAND.COM and in cmd.exe), the dir command returns the result as plain text. Example output:

07/24/2025  09:15 PM         1,428  my_script.js
07/25/2025  08:01 AM         3,980  report.html

Suppose you want to extract the filename and size of each file. You would have to parse the strings manually:

for /f "tokens=5,6" %a in ('dir ^| findstr /R "[0-9][0-9].[0-9][0-9].[0-9][0-9][0-9][0-9]"') do @echo %a %b

• This is terribly difficult to read, depends on the locale, date format, and font. And it breaks with spaces in the names.

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✅ PowerShell: objects instead of text

✔ Simple and readable example:

Get-ChildItem | Select-Object Name, Length

Result:

Name          Length
----          ------
my_script.js   1428
report.html    3980

• Get-ChildItem returns an array of file/folder objects
• Select-Object allows you to easily get the required properties

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🔍 What does Get-ChildItem actually return?

$item = Get-ChildItem -Path .\my_script.js
$item | Get-Member

Result:

TypeName: System.IO.FileInfo

Name         MemberType     Definition
----         ---------      ----------
Length       Property       long Length {get;}
Name         Property       string Name {get;}
CreationTime Property       datetime CreationTime {get;set;}
Delete       Method         void Delete()
...

PowerShell returns System.IO.FileInfo objects, which have:

• 🧱 Properties (Name, Length, CreationTime, Extension, …)
• 🛠 Methods (Delete(), CopyTo(), MoveTo(), etc.)

You work with full-fledged objects, not with strings.

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“Verb-Noun” Syntax:

PowerShell uses a strict and logical command syntax: Verb-Noun

Verb	What it does
Get-	Get
Set-	Set
New-	Create
Remove-	Delete
Start-	Start
Stop-	Stop

Noun	What it works on
Process	Process
Service	Service
Item	File/folder
EventLog	Event logs
Computer	Computer

🔄 Examples:

What to do	Command
Get processes	Get-Process
Stop a service	Stop-Service
Create a new file	New-Item
Get folder contents	Get-ChildItem
Delete a file	Remove-Item

➡ Even if you don’t know the exact command, you can guess it from the meaning — and you’ll almost always be right.

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The Get-Help cmdlet is your main assistant.

1. Get help about help itself: Get-Help Get-Help
2. Get basic help about the command for working with processes: Get-Help Get-Process
3. See examples of how to use this command: Get-Help Get-Process -Examples This is an incredibly useful parameter that often provides ready-made solutions for your tasks.
4. Get the most detailed information about the command: Get-Help Get-Process -Full

In the next part: the pipeline or command chain (PipeLines)