PowerShell/Misc/FAQ.md
Markus Fleschutz 958265793c
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PowerShell FAQ

What is PowerShell?

PowerShell is a task automation and configuration management framework from Microsoft, consisting of a command-line shell and associated scripting language.

Why use PowerShell?

How to get PowerShell?

  • On Windows 7 and newer PowerShell is provided by default. However, script execution is not allowed by default (execution policy is "restricted"). To enable this, enter as administrator:
    $ Set-ExecutionPolicy RemoteSigned
    
  • On CentOS, Debian, Docker, Fedora, macOS, openSUSE, Red Hat, Ubuntu visit https://github.com/PowerShell/PowerShell for installation.
  • Want to use Snaps? Install the PowerShell snap by executing:
    $ snap install PowerShell
    $ ln -s /snap/bin/pwsh /usr/bin/pwsh
    

How to get the PowerShell Scripts?

How to use PowerShell by Default?

  • On Linux: make sure PowerShell is installed, then execute: chsh -s /usr/bin/pwsh <username>. In case you experience an "invalid shell" error, add "/usr/bin/pwsh" to /etc/shells.
  • On Windows: no need to, PowerShell is the default shell

How to add the Scripts to the Search Path?

Want to use the PowerShell scripts everywhere on the command-line? Then you need to add the Scripts/ subfolder to the search path:

  • On Linux using Bash: edit .profile in your home directory and add the line: PATH="$PATH:/path/to/PowerShell/Scripts"
  • On Windows: open the environment variables dialogue and add the full path to Scripts/ to the system environment variable "Path"

How to use PowerShell in Context Menus?

  • to enable "right-click > New > Windows PowerShell Script" execute Add_ps1_to_New_context_menu.reg in subfolder Misc/
  • to disable this execute Remove_ps1_from_New_context_menu.reg in subfolder Misc/

How to edit the PowerShell Scripts?

  • use PowerShell ISE (Integrated Scripting Environment) to write, test and debug scripts (available for free on Windows only).
  • use Visual Studio Code supporting syntax highlighting, on-the-fly problem checking and an integrated PowerShell Console (available for free on Linux, Mac OS and Windows).
  • or simply use your favorite text editor

How to write good PowerShell Scripts?

Each PowerShell script should follow the 10 golden rules:

  1. the filename should be named <verb>-<object>.ps1
  2. the first line reads #!/usr/bin/pwsh (to support Linux)
  3. the script has execute file permissions: chmod a+rx (to support Linux)
  4. provide a comment-based help with syntax, description, link, author, and license
  5. check the requirements (e.g. #Requires -RunAsAdministrator, or #Requires -Version 3)
  6. prefer command-line options, else ask the user
  7. recommended is Set-StrictMode -Version Latest to enable additional error checking
  8. for readibility use UpperCamelCase for variables and functions, lowerCamelCase for everything else
  9. on error call write-error with keyword "ERROR:" (to support log parsers) and exit the error code (mostly 1)
  10. on success exit with error code 0 (exit 0)

Your Question is not answered here?

Send your question to: markus [at] fleschutz [dot] de