This series is in four parts: This is part 1

• Part 1: Help, Syntax, Display and Files 
• Part 2: Variables, Parameters, Properties, and Objects,
• Part 3: Collections, Hashtables, Arrays and Strings 
• Part 4: Accessing, Handling and Writing Data 

Well, yes, it would be an onerous task indeed to deliver everything. But per the Pareto principle, roughly  eighty percent of what you could want to know about PowerShell is here in this series of articles; possibly more!  You will tend to learn the other twenty percent  as you go, and you may not need  it for quite a ways into your PowerShell explorations.  I feel compelled to confess that some of the entries are not, strictly speaking, on one physical line, but  are written in such a way that, if you really want to run them in one line, you can just remove the line breaks and they will work. (Note that that is not generally true of PowerShell syntax.)

This series of articles evolved out of my own notes on PowerShell as I poked and prodded it to show me more. As my collection  burgeoned, I began to organize them until I had one-line recipes for most any simple PowerShell task. Simple, though, does not mean trivial. You can do quite a lot in one line of PowerShell, such as grabbing the contents of specific elements of a web page or converting a CSV file into a collection of PowerShell objects.

This collection of PowerShell one-liners is organized as follows:

Part 1

begins by showing you how to have PowerShell itself help you figure out what you need to do to accomplish a task, covering the help system as well as its handy command-line intellisense. The next sections deal with locations, files, and paths: the basic currency of any shell. You are introduced to some basic but key syntactic constructs and then ways to cast your output in list, table, grid, or chart form.

Part 2

moves into details on variables, parameters, properties, and objects, providing insight into the richness of the PowerShell programming language. Part 2 is rounded out with a few other vital bits on leveraging the PowerShell environment.

Part 3

covers the two fundamental data structures of PowerShell: the collection (array) and the hash table (dictionary), examining everything from creating, accessing, iterating, ordering, and selecting. Part 3 also covers converting between strings and arrays, and rounds out with techniques for searching, most commonly applicable to files (searching both directory structures as well as file contents).

Part 4

is your information source for a variety of input and output techniques: reading and writing files; writing the various output streams; file housekeeping operations; and various techniques related to CSV, JSON, database, network, and XML.

Each part of this series is available as both an online reference here at Simple-Talk.com, in a wide-form as well, and as a downloadable wallchart (from the link at the bottom of the article) in PDF format for those who prefer a printed copy near at hand. Please keep in mind though that this is a quick reference, not a tutorial. So while there are a few brief introductory remarks for each section, there is very little explanation for any given incantation. But do not let that scare you off-jump in and try things! You should find more than a few “aha!” moments ahead of you!

Notes on using the tables:

• A command will typically use full names of cmdlets but the examples will often use aliases for brevity. Example: Get-Help has aliases man and help. This has the side benefit of showing you both long and short names to invoke many commands.
• Most tables contain either 3 or 4 columns: a description of an action; the generic command syntax to perform that action; an example invocation of that command; and optionally an output column showing the result of that example where feasible.
• For clarity, embedded newlines (`n) and embedded return/newline combinations (`r`n) are highlighted as shown.
• Many actions in PowerShell can be performed in more than one way. The goal here is to show just the simplest which may mean displaying more than one command if they are about equally straightforward. In such cases the different commands are numbered with square brackets (e.g. “[1]”). Multiple commands generally mean multiple examples, which are similarly numbered.
• Most commands will work with PowerShell version 2 and above, though some require at least version 3. So if you are still running v2 and encounter an issue that is likely your culprit.
• The vast majority of commands are built-in, i.e. supplied by Microsoft. There are a few sprinkled about that require loading an additional module or script, but their usefulness makes them worth including in this compendium. These “add-ins” will be demarcated with angle brackets, e.g. <<pscx>> denotes the popular PowerShell Community Extensions (http://pscx.codeplex.com/).
• There are many links included for further reading; these are active hyperlinks that you may select if you are working online, but the URLs themselves are also explicitly provided (as in the previous bullet) in case you have a paper copy.

What’s What and What’s Where

This is your starting point when you are staring at a PowerShell prompt, knowing not what to do. Find out what commands are available, read help on PowerShell concepts, learn about auto-completion of cmdlets and parameters, see what command an alias refers to, and more.  Before even going to the first entry, though, it is useful to learn one thing: PowerShell has help available on both commands and concepts. You can look up a command simply with, for example, Get-Help Get-ChildItem (# 1 below). Or you can search for a command with a substring, e.g. Get-Help file (#3). But as with any programming language you have to know syntax, semantics, structures, … in short all those conceptual items that let you work with commands. If you want to know about variables, for example, you have merely to say Get-Help about_variables. All conceptual topics begin with the “about_” prefix (#11).

Not at first, but in short order, you will want to be able to find meta-details about commands as well. By that, I mean to answer questions like: What type of objects does a cmdlet return? Does a cmdlet have one or multiple sets of parameters available?  Where does a cmdlet come from? All of those meta-details can be seen from entry 20 below.

Location, Location, Location

See where you are or where you have been and navigate to where you want to be; understand the difference between your PowerShell current location and your Windows working directory; get relative or absolute paths for files or directories.

Files and Paths and Things

You can list contents of disk folders with Get-ChildItem just as you could use dir from DOS. But Get-ChildItem also lets you examine environment variables, local variables, aliases, registry paths, even database objects with the same syntax! See about_providers (http://bit.ly/1ghdcvb) and PS Provider Help (http://bit.ly/1dHlC7r) for more details.

Basic Syntactic Elements

Like with learning most things, you need to learn to crawl before you can learn to run. This section shows you how to do some of the most basic but important things, things that will soon become second nature: knowing what is true and what is false; adding comments; continuing a command across multiple lines or, contrariwise, combining multiple commands on one line; and so forth. Arguably there should be one other important group of items included here: PowerShell operators. But I already published a wallchart on a set of common operators for strings and string arrays. See Harnessing PowerShell’s String Comparison and List-Filtering Features (http://bit.ly/1c20itX) for details on -eq, -like, -match, and -contains operators and their variations.

Display Options

According to Using Format Commands to Change Output View (http://bit.ly/N8b7oe) each format cmdlet (i.e. Format-Table and Format-List) has default properties that will be used if you do not specify specific properties to display. But the documentation does not reveal what those defaults are or how they vary depending on the type of input object. Also, the default properties differ between Format-Table and Format-List. Finally, keep in mind that if Select-Object is the last cmdlet in your command sequence, it implicitly uses Format-Table or Format-List selecting one or the other based on the number and width of output fields. (And while the included images were not designed for you to make out the actual text, you can discern the representation of the data from those thumbnails.)

Prompts and Pauses

Some basic interactivity entries, showing how to get input from a user, how to pause and resume, and how to clear the window contents.

Casts, Type Accelerators, and .NET Classes

You are no doubt familiar with type casting in .NET languages. PowerShell provides the same casting capability but enhances it with a new concept, type accelerators. Type accelerators are simply aliases for .NET framework classes. Note that in PowerShell you can always omit the “System.” prefix of a class if it has one to save typing, so you could use, say, DateTime rather than System.DateTime. But with type accelerators you can get a lot more concise than that. For example, you can just use [wmi] instead of System.Management.ManagementObject. As far as casting, in PowerShell you can cast to any .NET type that has either a cast operator or a constructor that accepts the source type (see the Net.IpAddress entry below). Finally, you can use .NET type names to access static members of .NET classes (see the DateTime.Now entry below).

Conclusion

That’s it for part 1; keep an eye out for more in the near future! While I have been over the recipes presented numerous times to weed out errors and inaccuracies, I think I may have missed one. If you locate it, please share your findings in the comments below!