What Is PowerShell?
PowerShell is an open-source, command-line interface tool that allows developers to automate tasks and configurations using code. The tool allows users to control the computer via a shell interface directly with the operating system.
What Is PowerShell?
PowerShell is an open-source shell program and a scripting language built on Microsoft .NET technology. Its command-line interface allows developers to automate tasks and configurations using code. When used as a shell, PowerShell conveys instructions to the operating system via instructions submitted via the command line. This feature enables users to automate repetitive processes and to repeat instructions as the system saves them for reuse. As a scripting language, PowerShell passes instructions to other software. This feature makes it possible to modify software’s functionality, automate tasks, extract data from data sets, and more easily adjust configurations.
PowerShell commands are interpreted line by line with an interpreter instead of a compiler, unlike programming languages like C, Erlang, or Go.
In this Article
History of PowerShell
Jeffery Snover created PowerShell, but its original name was Monad. In a 2002 whitepaper, the Monad Manifesto, Snover said PowerShell needed to be developed as the Windows structure did not permit Unix tools. Monad was to work as an extensible command-line interface with fresh designs that can host Unix tools.
This was first illustrated in October 2003 at the Professional Development Conference in Los Angeles. A private beta followed this, then three public betas in June 2005, September 2005, and January 2006, respectively.
In April 2006, the name was changed from Monad to Windows PowerShell. This went through five different revisions; by 2016, Windows PowerShell version 5.1 was launched. These versions were limited to use on Microsoft operating systems.
To solve this issue, the sixth edition of Windows PowerShell was released as open-source program in 2016. The name was changed to PowerShell core, and it can be used on macOS, Ubuntu, and CentOS because it runs on .NET Core.
The PowerShell project is thriving for Windows as the program still reflects many of the core principles of the 2002 Monad Manifesto. It has even gone beyond the tenets of the manifesto by becoming open-source, increasing the number of cmdlets beyond the initial vision of a few hundred, and evolving and adapting to integrate with new technologies like the cloud, containers, and more.
How Does PowerShell Work?
Generally, PowerShell functions more like a programming language than a command-line program. PowerShell works with objects. In fact, everything in PowerShell is an object. These objects represent attributes (properties) or instructions (methods). They can be made continuous to work through the program as an input or output. PowerShell manipulates objects with four different types of commands:
1. Cmdlets
Cmdlets, pronounced as command-lets, are the basic single-function commands of PowerShell. If PowerShell is a paragraph, cmdlets are letters of every word in the section. One can use them singly to carry out a function and combined to carry out more significant functions. Each cmdlet still works as an individual function to contribute to the cmdlet output in the combined function.
However, cmdlets are not written in PowerShell. They are written in another language, compiled, and made available in PowerShell. Cmdlets is a critical command in PowerShell as their function limit depends on the developer’s creativity. Developers and DevOps engineers may use “pipes” to pass a cmdlet output into another cmdlet’s input as an object.
2. PowerShell functions
Functions serve as one of the many commands that execute code in PowerShell. Unlike cmdlets, you write functions in PowerShell language. You form a sequence of instructions and achieve them by invoking the functions. Users provide parameters as input, while the output can either display on the screen or get piped to another function or cmdlet’s input.
There are two functions in the power shell: basic and advanced. The simplest form of a function is the basic function. With basic functions, there are no built-in features of inherited features. There’s only a set of curly brackets containing the function’s body. Advanced functions are functions that have properties of a basic function as its core, but have additional features. These functions carry built-in features which give it more functionality.
3. PowerShell scripts
Users write PowerShell scripts with cmdlets. These scripts result in different automation tasks. There are three types of commands in a script. The “get” command is the first one used to retrieve data from a file system. The “set” command is used to edit the windows component information. This includes assigning properties to different components. The “remove” command is used to delete operations completely. PowerShell scripts reduce code complexity while writing codes and other use cases of automation.
4. Executable commands
Executable commands are the commands used to run executable files, which have the .exe extension and are components of Microsoft Windows. You can use three commands to run .exe files. The first is with the “Invoke-expression” command. This is arguably the most popular method of running these files. The second command is the “start-process” cmdlet. This command starts more than one process on your device but gives the same result as the first command. The third option is typing “.\” before the file’s name. This is the easiest method, but all alternatives run the .exe file.
PowerShell Use Cases
As mentioned, PowerShell is a double-function attribute. However, the two main functions of PowerShell embed more modalities, and these modalities (or use cases) are the reasons for PowerShell’s popularity.
1. Enabling task automation
The first of these reasons is task automation in DevOps. As a scripting language, PowerShell creates automation. Automation spans every use case of PowerShell. Users may create automations with other scripting languages, but they often use PowerShell because of the unique format system. PowerShell is also extensible with functions, classes, cmdlets, and modules.
2. Driving data accessibility
Another reason for PowerShell’s popularity is data accessibility. A significant part of PowerShell use cases is administrative activities. In large computer networks, many services work independently and are controlled by a central IT admin. PowerShell offers the IT admin easy access to different data stores of network services such as file systems or registries.
3. Managing “infrastructure as code”
As a third reason, PowerShell employs a management framework that enables users to manage their company’s infrastructure with configuration as a code. This framework is the Desired State Configuration (DSC). Managers or IT admins obtain PowerShell skills to know how to push or pull configuration models in PowerShell for smooth composability as the need may be. They also need these skills to enforce configuration settings, obtain repeatable deployments and create declarative configurations.
4. Facilitating remote commands
Finally, PowerShell has such a wide acceptance rate and use case because of its ability to facilitate remote command. Remote use is the new gold rush and software or tools that allow remote work to gain widespread popularity. With PowerShell, administrators can perform remote operations on multiple systems. This is possible through Windows Management instrumentation and WS-management protocol.
Advantages of PowerShell
There are other shells and many scripting languages, but PowerShell as a single component has advantages that make it “pro-choice.” These are the top advantages of PowerShell for users:
1. Extensible format system
Using PowerShell, it is straightforward for a user to format his input and get an output however he wants. The tool offers three formatting methods. One can easily manipulate each method for any setting the user needs.
The first format method is “format-wide.” In this method, a user can display only one property of an object. One can use this to fill columns in a table or make lists. Another method is “format-list.” This method allows users to display properties of objects as a list, with each property on a new line. On the third side of the dice is the “format table”. This method makes it easy for users to present output as a table. There are parameters like “Autosize,” “wrap,” and “groupby” to use in organizing the columns of the table.
2. Built-in data formats
Data formats support PowerShell, that one can use to store and transfer data and make data human-readable and machine-readable. These data formats include comma-separated value (CSV), JavaScript Object Notation (JSON), and Extensible Markup Language (XML). CSV format is an inbuilt data format that stores table data as plain text.
The JSON format is used for immediate communication between a browser and a client. It is an open standard format and also a human-readable format. When the browser provides information, users can convert it into PowerShell data using the “Invoke-WebRequest” or “Invoke-RestMethod” commands. The XML format is also machine and human-readable. It is used to obtain data from a webpage, edit it and post it back. It is also used for configuring application performance in PowerShell.
3. Extended type system
There is an extended type system (ETS) that script and cmdlet developers can use to manipulate .NET objects. This system is done using the PSObject object. One can use the PSObject object to extend object types in two ways. In the first method, the PSObject object displays different views of specific object types, which is referred to as an adapted view.
In the second method, the PSObject object provides means of adding members to an existing object. These new members extend the base object (the initial object that is worked on) by giving it additional information that can be useful in scripting.
4. Secure scripting engine
PowerShell places the security in the hands of the user with the configuration management feature. This feature allows users to decide which scripts to run through visually review. Since users often don’t visually notice malicious scripts, automated security policies are in place to assist them.
PowerShell uses an execution policy as one of its security strategies. This execution policy determines the conditions under which PowerShell will execute specific configuration files and scripts. The group policy setting allows administrators to set this policy across various computers and devices on the Windows platform.
However, this policy is only active when the user decides. When made active, PowerShell runs only scripts authorized by an identifiable name. This is a fair choice against running malicious scripts on your computer that may allow cyber threats to enter.
5. Self-service development
PowerShell enables each team in an Exchange to build their cmdlets by themselves. This is a significant advantage over other options. This “self-service” model is crucial as it enables developers to build the management of their features even as they write their features.
This results in better management and, in turn, quality products. This is because products are most beneficial when component teams are “in charge” of their features. This ensures the users of a well-structured feature. It also makes the building faster as one can test the feature with real codes early. This eliminates bottlenecks in the building of features and scripts.
6. Consistent API
APIs such as Windows Management Instrumentation (WMI) and Component Object Model (COM) often demonstrate inconsistencies or incompleteness on Windows. This makes them inefficient in carrying requests to and from the browser.
However, PowerShell is a 100% comprehensive and consistent API that 3rd parties use. This is the REST API from the power shell, which you activate using the “Invoked-RestMethod” cmdlet. This activation is simply a request through HTTPS or HTTP. The API then retrieves the data through a URL.
7. Easy automation
PowerShell uses the simple, single-function command-lets tool to implement tasks. As a single-function tool, users can use cmdlets separately or combined to solve complex tasks. The PowerShell comes with more than ninety basic cmdlets. Developers can create more cmdlets as needed. One can also share these self-developed cmdlets with other users as PowerShell is an open-source feature. This makes it easy for developers to create automation to solve repetitive tasks.
Knowledge of building these cmdlets gives a developer an upper hand over others. This advantage of PowerShell sets makes its users “pro-choice” in different settings.
8. Cross-product composability
PowerShell has a great cross-product composability model, which makes it suitable for several services and products. In this way, you can use PowerShell for different services, but a single admin could still control it. This makes PowerShell functional in networks where various services are dependent or independent of each other, like a corporate network.
9. Easy access to information
Although all command lines can access the computer’s file system, PowerShell can provide access to hard-to-access data. Microsoft built PowerShell on the .NET framework. This unique feature gives IT professionals access to automate and remotely control every Windows PC in a corporate network. With a single line of command-line code, IT admins can have deep visibility and control across every file system in their network.
10. Corporate network management
Despite Office 365 Administration web portal being the central management station for corporate Microsoft Office 365, PowerShell has many useful administration commands that are absent in the latter. An example of a command is the default option for password setting. The options in the admin web portal are either for all users to change passwords regularly or for no user to change their password. Using PowerShell, an IT admin can build a 2-factor authentication (2FA) system to prevent users from changing passwords regularly.
11. Discoverability
One highly advantageous feature of PowerShell is the Get-command cmdlets. With this command, end-users and programmers can discover a whole set of commands and features available on PowerShell. Get-command creates a list of all the cmdlets and functions that one can find in that computer at the time of the request. Users can also nickname cmdlets or give them aliases, which you can find by running the Get-Alias cmdlet. This feature makes using the program easier, regardless of how often you use the tool.
12. Insight into Microsoft certification exams
While most may not consider this an advantage, it remains a huge factor for some. Microsoft has recently been adding questions specific to PowerShell to their certification exams. While they may not require you to know the full syntax of each command, you should be able to see the use of different commands in different instances. So for those planning to take a Microsoft Azure DevOps certification exam, using PowerShell over other programs can be a better choice.
Using PowerShell
If you already use the Windows operating system, starting with PowerShell is easy. For example, you can access the PowerShell application built into Windows 11 by simply typing into the search bar. IT administrators can also explore the PowerShell Integrated Scripting Environment (ISE) platform, which you can install separately.
PowerShell ISE is a graphical user interface (GUI) application that makes it easier to check, debug, and execute scripts without getting into code complications. Knowing PowerShell can help simplify IT and DevOps Tasks and reduce dependence on third-party tools for greater control.
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