PowerShell basics

What it is

PowerShellA shell from the Windows world that works with objects, not just text. On WolOS it is an option for terminal windows. is a shellThe program inside a terminal that reads what you type and runs it. WolOS uses zsh unless you choose another. that many people know from Windows. Its commands have names made of a verb and a noun (Get-ChildItem, Set-Location), and instead of plain text it hands objects from one command to the next: a list of files is a list of files with names, sizes and dates, not lines of text you have to cut apart.

On WolOS PowerShell is one choice next to zsh. It comes with the Console module and, once installed, you can open it inside any terminal or make it the shell every new terminal window opens in.

Why WolOS does it this way

If you have years of PowerShell in your fingers, you should not have to relearn them to use a terminal on WolOS. So PowerShell gets the same treatment as zsh: the same prompt (folder, project branch, an arrow that turns red after a failure), the same keys, a history of 50,000 lines without duplicates, grey suggestions from your history, and the colours of your theme. What WolOS does not change is the shell your account logs in with, which stays zsh: the desktop and many programs hand it short commands written for zsh, and PowerShell reads those differently.

How

Add PowerShell

1. Open System Settings > Modules.
2. Find Console and click Install. It asks for an administrator's password, because it adds programs for the whole computer; PowerShell itself goes into your account only.
3. Wait until Console shows Ready. See Modules.

Open it

• For one session: in any terminal, type pwsh and press Return. The prompt changes to PowerShell's. Type exit to go back to zsh.
• For every new terminal window: System Settings > General > Shell in the terminal, choose pwsh. You see under the menu "New terminal windows open in it. You still log in with zsh." Windows that are already open keep their shell.

The commands are Verb-Noun

The verbs are few and always mean the same: Get reads, Set changes, New makes, Remove deletes. Once you know them you can often guess a command: Get-Date, Get-Process, Get-Command *Item* (every command with "Item" in its name). Capitals do not matter.

Options start with a dash and can be shortened

Get-ChildItem -Recurse -Filter *.jpg lists every JPEG here and in all folders below. You may shorten an option as long as it stays clear (-Rec), and Tab completes it: type Get-ChildItem - and press Tab to walk through every option.

Objects in the pipeline

The bar | hands the result of one command to the next, as in zsh, but what travels is objects. That makes sorting, filtering and choosing columns one word each:

Get-ChildItem ~/Pictures -Recurse -Filter *.jpg |
    Sort-Object Length -Descending |
    Select-Object -First 5 Name, Length

This lists your five biggest photos with their names and sizes. Sort-Object Length sorts by size because every file object has a Length; nothing had to be cut out of text. Where-Object filters: Get-ChildItem | Where-Object Length -gt 1MB keeps files over one megabyte.

Variables

A name with $ in front holds a value: $folder = "~/Documents", then Get-ChildItem $folder. $HOME is your home folder, and $PROFILE is the path of your own settings file.

Keys

They are the same as in zsh, so switching between the two is painless:

A line that starts with a space is not kept in the history.

Your own settings

Type $PROFILE to see where your settings file is. Open it with code $PROFILE (if you have the Developer module) or any text editor, add your own functions or aliases, and open a new window. WolOS's own settings are read first and yours afterwards, and updates never touch your file.

A worked example

Bill moved to WolOS from Windows. He installs the Console module, chooses pwsh in System Settings > General > Shell in the terminal, and opens a terminal. To find what fills his Downloads folder he types gci ~/Downloads | sort Length -Desc | select -First 3 Name, Length and sees his three biggest downloads. He removes an old installer with Remove-Item ~/Downloads/setup.exe. Later, a tutorial gives him a zsh command; he types zsh, pastes it, and exit brings him back to PowerShell.

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