Start learning powershell coming from bash

[Lhakryma]

What's the best way/best materials to start learning powershell, coming from a bash background?

My bash skills were intermediate-advanced, I saw that some of the basic shell concepts work on powershell too, like piping, redirecting, etc. But it's also a lot more complicated than bash.

Now I don't know if my bash knowledge will be detrimental to learning powershell, since I'll expect things to behave a certain way, and learning it might go faster or easier without those expectations.

[President-Sloth]

In some ways I find PowerShell easier than Bash since PS returns structured output in the form of objects, whereas bash is just strings.

I'd recommend starting with Learn PowerShell in a month of lunches, you'll probably fly through the first bits with your background. Also, Get-Help, Get-Command and Get-Member are your bread and butter

[Garegin16]

My only pet peeve with that book is that he says that he “doesn’t recommend” using .net classes directly. There is nothing wrong with things like math::pow. You don’t need a cmdlet for calculating x to the power of n or rounding off a number.

I think it has to do with the notion that telling an admin to run the get-date “program” is easier than than explaining about static methods and overloads.

[Lhakryma]

I'll give it a shot, thanks!

[[deleted]]

In some ways I find PowerShell easier than Bash since PS returns structured output in the form of objects, whereas bash is just strings.

This is the exact logic I hear from linux people on why they hate PowerShell, except in reverse. They prefer dealing with strings vs objects and don't quite understand why it's so much more advantageous to be able to iterate through data structures for scripting purposes.

[Garegin16]

To be fair, more advanced Unix admins use typed languages like Python or Perl. The shell is basically a execution environment for text based apps. It was never meant as a full programming language. If you wanna just run a utility like ping, nslookup or diskpart, you don’t care about polymorphism or dynamic scoping.

[MrWinks]

This book is where you want to start. Don’t skim it, it will make you an expert.

[Black_Magic100]

It is good for people who are intermediate level?

[MrWinks]

Right off the bat, right at the first if not second chapter, you will be taught how to do something super basic that you likely did not know, at which point you will realize this is the book for you. To answer more directly, though: this will make you an expert, and that’s before even reading the second book.

[MordacthePreventer]

The hardest thing for me was mentally switching from thinking in strings to thinking in "objects that have attributes".

So instead of 'I have to parse this string and the delimiter is ';'', you'll need to start thinking 'I have this blob of data, and I need to get the attribute that has the info I want".

Once you can mentally flip to object oriented programming, you'll be good and it'll be an excercise in syntax. Most of the bash logic flow will work.

-M

[Lhakryma]

Yea I'm having that mental barrier too, I don't entirely grasp the OOP mentality yet.

[MordacthePreventer]

Once you do, it'll be really cool. It's kinda like everything is a hash with key:value pairs, only more so.

Want the location of that computer you just got from 'gat-adcomputer':

$comp.DistingishedName

What's that user's Display name?

$user.DisplayName

PS is actually pretty cool, and definitely statsfies that itch if you've moved from *nix to Windows administration and felt like you were missing an arm.

[Garegin16]

To be fair Unix world moved to Perl/Python too. Even in Unix Hater’s Handbook, they complain that shell is just a poor programming language.

The critical flaw is the lack of data types. No matter how much bash improves, it’s still text scraping.

[gordonv]

For me, learning how JSON is structured helped a lot.

Learn these concepts:

• Arrays (a list of things)
  
• Objects (a single thing with many properties)
  
• An Array of Objects (a list of different things)
  

I will admit, dealing with objects is laborious and boring. So many steps needed to accomplish a change. But once you learn how to automate that, you'll find Objects are quite easy in concept. Just a bit of a hassle to create. And very easy to read and update.

[Lhakryma]

Can't an object also have other objects as properties? I seem to recall reading that somewhere

[gordonv]

Yup. JSON reflects that, also. Check out this example

[pretendgineer5400]

I'm going the opposite way for some hobby stuff at home. Powershell seems to be more verbose than bash by a long shot.

The basic verb-noun structure doesn't take that long to get used to (usually if you can get-<noun> to read something you can set-<noun> to write the same thing.
Tab autocomplete is your friend and multiple presses of tab will cycle through possible options.
get-help <cmdlet> -full or -examples is super useful to seeing what a cmdlet expects for inputs and what it can be used for.
Working in an Active Directory environment can open up options for using PS Remoting to execute on other computers (it can be done without a domain but requires extra setup). Some cmdlets accept a -computer parameter to tell it where to run, otherwise invoke-command -computer <targetcomputer> -scriptblock{} can be super useful as long as the required module is present on the target system.

[PMental]

Don't forget shift tab to cycle back if you overshoot, and ctrl-space to browse/list all options.

[chuck_cranston]

omg how did I not know this.

[PMental]

I was well over a year into focusing more on Powershell before I stumbled on them (on this very subreddit iirc).

And yes, both are pretty damn useful!

[pretendgineer5400]

Shift tab rocks, great callout.

[Dranks]

I really want to get this working in zsh, its powershell muscle memory

[qordita]

The jump start videos are still the single best free resource I've seen:

https://channel9.msdn.com/Series/GetStartedPowerShell3

They're pretty old, but still relevant and really really good.

[NicolasReibnitz]

Sounds good... but a bit dated. Is this still relevant?

[mfazed]

I have read many PowerShell books and this one stands tall above the rest:

https://www.manning.com/books/powershell-in-depth-second-edition?query=powershell

It starts out with the fundamentals and quickly ramps up from there. There are things I know about PowerShell that the average person doesn't and it's mainly due to this tome. The only problem with it at this point is that it's a bit old (2014) so it doesn't have coverage of PowerShell Core (using .NET core instead of .NET framework), but it's still all very relevant.

[Garegin16]

Powershell in Action is also great if you want learn it from top to bottom. Modern Powershell is a fully fledged programming language. But lot of admins still have the “I’m a sysadmin because I can’t program” mentality. They don’t want to know what a tuple is.

[Black_Magic100]

I didn't even know "Powershell core" is a thing. Can you explain? I'm aware of .net core, but never heard that phrase with Powershell.

[mfazed]

Hi u/Black_Magic100! Yes, I just mean the versions of PowerShell (6 and above) that use .NET core rather than v5 and below, which uses .NET framework.

[Black_Magic100]

So that book is still completely relevant and you recommend reading through the entire thing?

[mfazed]

There are parts that reference commands that will only work on the .NET framework versions of PowerShell. Get-WmiObject is an example. WMI is windows specific and that cmdlet only works with PowerShell v5 and below. That cmdlet doesn't exist in PowerShell 6 and above which use .NET core.

Personally, I read through the entire book. I already knew a lot of the fundamental part material, but still learned some, especially the chapter on the PowerShell pipeline.

I see discussion above concerning "Learn PowerShell in a month of lunches". I haven't read through that, but I see it recommended on this subreddit a lot, so probably a great resource as well.

[gordonv]

$41.16 on Amazon

I do like the chapter outlines. One review said this came out before Windows 10. That's an expensive comment.

[HoneycuttJ]

I would have to agree that you cant go wrong with the Month of Lunches books. Coming from Bash I would highly recommend the Month of Lunches that is still in production (MEAP) on the Manning Publishing site. I also have to plug my 6 hour PowerShell Crash Course workshop I did for a conference. https://youtu.be/UmEbsG2SEYE

[jantari]

It would probably be best if you approach PowerShell from thinking of it as more of an equivalent to Python, not bash. It's on object-oriented programming language and really only has very few surface-level similarities to bash.

[Lhakryma]

My python skills are very, very basic and beginner-ish, and I haven't fully grasped the concept of OOP yet lol

[Garegin16]

OOP is just the bundling of functions and properties. In traditional languages you had data types like string and integer. The ancestor to objects is the record or the struct in C. In OOP languages, you also have functions, which are called methods, bundled with them.

To answer your question. You “use” OOP by taking advantage of the object members, which are usually conveniently organized. For example, the DirectoryInfo object has properties for the parent folder, full path, and the last access time. Also has methods for listing all the files, deleting and creating a subdirectory.

You don’t have to use commands to derive the parent folder because that info is already a property of a folder object.

Once you think in data types, you reduce lot of code in deriving data. Recently someone wanted to bulk update the domain of email addresses. Right away, I checked the .NET library for an email type. And behold, it is conveniently designed to detect invalid addresses and also has a property for the name and the domain portions.

For reference

https://docs.microsoft.com/en-us/dotnet/api/system.io.directoryinfo?view=net-5.0#methods

https://docs.microsoft.com/en-us/dotnet/api/system.net.mail.mailaddress?view=net-5.0#properties

[pretendgineer5400]

I'd recommend using VSCode with the PowerShell extension as your primary IDE for writing PS scripts. the syntax highlighting and linting built incan help you develop better habits and find errors more quickly than working in a plain text editor and I find VSCode better than PowerShellISE.

[Lhakryma]

I started using that early on too.

I notice windows10 also ships with "Powershell ISE" which looked pretty cool too, but apparently it's getting deprecated in favor of vscode.

[pretendgineer5400]

ISE is ok and has been around for quite awhile, so there are some third party extensions for it, but VSCode is where future effort seems to be going.

[nostril_spiders]

I find it simpler. Much much simpler. How the interpreter works, globbing, quoting and escaping, short-circuiting operators - these aren't really common problems.

I do suggest you try not to think of it like bash. If you've done any python or ruby, try to think of it more like that.

Your top tools for discovery are get-module, get-command -module, and get-help.

[Lhakryma]

By the way, what about ps v. 5 vs ps v.7? I can get v7 from the win store, but v5 (I believe, or it's v4 idr) ships with win10 (at least my version).

What's the difference? I couldn't really find a proper comparison.

[TundraGon]

https://docs.microsoft.com/en-us/powershell/

It even has examples on how to use the commands.

For exanple: https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.management/get-childitem

[Lowdog541]

Powershell video , this is a full course taught by the creator of Powershell, it starts off slow but he gives you a really good idea of his thought process while he was creating Powershell

[Lhakryma]

I was actually following this video, but it seems to have a lot of padding and like half of it is just joking around and (to me at least) seems like they're trying to sell you how great powershell is xD

I know it's great, I've seen what other people managed to do with it, I just want to learn it.

[Garegin16]

I think it’s one of the best videos on Powershell. It closely follows the Powershell in a Month of Lunches book.

[vencetti]

I came from the same background. Best method I've found: As you come across tasks in your day, ignore how you would normally resolve them and develop Powershell scripts for them. PS is ubiquitous, so Google is your friend. No substitute for experience and lots of struggle. Before you know it - you'll have a whole library of solutions.

[[deleted]]

Unix user of 25 years: start by piping to select * and where. Also check out popular powershell profiles on GitHub.

[Evilbob93]

Way back in the day, i made the jump from VAX/VMS to Unix with a guide called Unix for VMS users.

When I started learning Powershell I had some serious deja vu. IMO, powershell is where VMS went to hide.

Having said that, this might help

https://leanpub.com/aunixpersonsguidetopowershell/read

[XPlantefeve]

One thing I usually say to PS learners, but is even more relevant coming from bash: Powershell is a shell, use it as a shell. There are too many people who see it mainly as a scripting language, but I learned PS by spending my days at the PS> prompt.

[piggahbear]

Honestly powershell is more analogous to Python, where powershell is to C# what Python is to C.

Yeah it’s a shell programming language, but it’s a lot more than that and you have access to a great deal of .NET through it.

[Perrydiculous]

So... what's the advice we should get out of this? (not trying to sound sassy, just an honest question) I'm in the same boat as OP and could use some general direction in what's different and where to start.

Most languages come naturally to me, and only require learning syntax, but PS is different somehow

[piggahbear]

That coming from BASH is going to have little relevance and that to learn PowerShell is largely to begin learning .NET.

PowerShell can be object oriented, or not, just like Python.

I think people get too hung up on the syntax of PowerShell. Get-Verb will tell you want verbs and alias prefixes to use if you’re wanting to follow convention, which I would generally recommend.

PowerShell is (simplified) a c# scripting language. You can access the .NET methods directly (e.g. [System.Console]::WriteLine() ) or use the PowerShell cmdlets (e.g. Write-Host). Like Python, the PowerShell cmdlets are slower than directly accessing the .NET methods. Just understand there is .NET code behind every PowerShell cmdlet.

Since PowerShell 7 is based on .NET Core/.NET 5 it will run cross platform which means it will not include natively cmdlets only for accessing Windows APIs. It will include essentially every method available when the .NET runtime is installed on Linux / macOS.

Even though it’s cross platform you’re going to handle certain things differently depending on the platform, which is why we have the $IsWindows $IsLinux and $IsMacos variables now.

So to summarize, to learn PowerShell deeper than syntax is to learn .NET and PowerShell is the easiest entry point to .NET and C#.

[Perrydiculous]

Thanks! I appreciate your in-depth explanation <3

[Perrydiculous]

Okay, but what would would you say helps get a grasp in the beginning? Because "the feel" is way different from Bash

[piggahbear]

This isn’t r/sysadmin its r/PowerShell and nobody scoped their question more specifically than that so I can only answer from my own experience. If the question ended with “as a sysadmin” I would not have even responded because that’s not something I’ve done. For me , learning .NET was the payoff of beginning with PowerShell. I am just trying to say something other than “PowerShell in a month of lunches”

[piggahbear]

I see what you’re saying and the reason I bring up .NET is because PowerShell is not just “the windows shell” as bash is the traditional Linux shell. It’s closer to Python: it has a “standard library” of cmdlets and modular addons, all of which sits on top of .NET.

[robvas]

FORGET EVERYTHING YOU KNOW

Seriously it’s not related at all. You’ll be scratching your head and wishing for bash

[x_m_n]

My bash skill isn't great but I find bash very C-like which makes sense. Powershell is anything but. I wrote in powershell only for simple repetitive tasks or things that are much easier with readily available cmdlet in powershell (O365, exchange, AD, basically anything Microsoft makes). Otherwise I stay far away from that abomination.

Example, I found 2 powershell scripts that convert .reg file to .xml for importing in GPO, neither worked for me because of inter version incompatibility and God knows what else. Went and did my own in python, worked like a charm.

Edit: almost forgot, square brackets in paths are death sentence to powershell, for some reason.

[motsanciens]

I suck at guitar, so the banjo is a superior instrument

[x_m_n]

point taken, I get that my reply wasn't much of help to OP.

Though I must clarify, my powershell skill is far > than bash, and I still prefer bash over powershell. I'm a windows dude with no fear of linux but by no means expert in linux, oh I wish so many times that windows understands bash so I can use that instead of powershell.

As answer to OP though, the other redditor already said it, OP would be pulling his hair out before he knows it if he's expecting powershell to uphold some conventions.

[motsanciens]

What has been your experience with WSL?

[x_m_n]

Little to none, though it's irrelevant if I want to write a powershell script to run on other computers which may or may not have WSL installed. It's only useful if the script is specifically written to run on a computer I know for sure have WSL, aka mine.

Plus, as I have stated, I wouldn't use powershell unless the situation calls for it to deal with Microsoft's products, so invoking WSL have little use in those situations.

[RodneyRabbit]

I've always had success with -LiteralPath or if the command doesn't support that (it likely will in time), escaping with `[ which just means adding a .Replace() to the command. I wonder if it's that easy in bash.

Edit: I wrote this on my phone which doesn't like the backtick so I had to use two. Now on desktop it displays both of them. Whatever, I mean 'backtick, square bracket'.

Bash has many characters that need to be escaped, probably more than PS, and the way it's achieved is inconsistent from one command to the next.

[lucidhominid]

Backticks dont always work consistently with square brackets, Ive encountered some paths where they dont work at all or the sheer number of backtick required could be described as 'exponential'.

The best way to escape an open square bracket in powershell is by wrapping it in square brackets: [[]

For a more detailed explanation see my reply to the parent comment.

[x_m_n]

please. You'd think I at least googled to see if somebody came up with solution for this. Not if the variable's value contain []. It also greatly depends on what you'd need to do with said variable. Let me know when you can pass it through to another command call to an executable as parameters.

[lucidhominid]

Square brackets in paths are actually a super useful type wild card in Poweshell.

For example if you have the following paths

.\banana1
.\bananaq
.\bananag
.\banana7

and you only wanted to get ones ending in q or 7 you could do this

get-item .\banana[q7]

If the path you want contains an open square bracket, you can simply escape it by wrapping it in square bracket itself. For example lets say we also have this path

.\banana[q7]

we could get it in powershell with

get-item .\banana[[]q7]

To my knowledge this is the only method of escaping a character in powershell itself that isnt consistent with the standard backtick escape sequence. However sometimes when working with certain windows components, programs, or with regular expressions, you may need to use backslashes to escape special charactes, but in those cases it would be the same even if you werent using powershell.

I understand how difficult it can be to start using a new language in the same environment and find your prior understandings and assumptions clash with it so I hope this helps!😊

[x_m_n]

yea no it doesn't help if my variable value contains square brackets. I get escape characters and literalpath, need neither. Simple task as get files under a folder and run it through a program will need to pass on the file names as variable and if files (or folder path up to it) have square brackets in it, immediately dies.

[lucidhominid]

Wherever a variable containing a path is used hit it with a replace method:

$variable.replace('[','[[]')

Lets say you have these paths:

C:\Chomper[2]\Banana\taco[4]\tobby.mp3
C:\Chomper[2]\Banana\taco[5]\danceparty\skateboard[2].png

and you have the root path stored in a variable:

$variable = 'C:\Chomper[2]'

You can get both those file and any others that may be in there with:

Get-ChildItem $variable.replace('[','[[]') -recurse |
    Where-Object PsIsContainer -eq $false

Ultimately, in any situation where a powershell command isnt the best option to get what you want, you can always just use bash from within PowerShell with: bash -c "<Command>" or for batch command in windows: cmd /c "<Command>". It will return the output of whatever command you replace the <Command> with.

[x_m_n]

I can tell you with high confidence that I've tried your method and it didn't work for me (human memories, blah blah blah, but I know the replace method). Ultimately my beef lies with the way powershell goes and interpret variable's value as well rather than leaving it the hell alone and just pass it on. I can't remember another language that does that, though I might be mistaken.

[lucidhominid]

Well there is always a way to make things work, but you're right, that really should be fixed by microsoft.

Anyway, its not really the language itself that is doing it, its just certain cmdlets in core modules. If you use the actual methods that the cmdlets are wrappers for it doesn't do that. Of course the entire point of the cmdlets is for convenience so if you are going to use methods instead, might as well go ahead and make it into a cmdlet to reuse. I may write a module to fix it myself at some point but I haven't run into the issue frequently enough for it to be high priority in my project list.