Your First Script

A script is a text file with a .ps1 extension containing PowerShell commands.

Writing and running a script

Create hello.ps1:

# illustrative
# hello.ps1 — my first script
$name = $env:USERNAME ?? $env:USER
Write-Output "Hello, $name!"
Write-Output "Today is $((Get-Date).DayOfWeek)."

Run it by path from the terminal:

PS C:\scripts> .\hello.ps1
Hello, ada!
Today is Tuesday.

The .\ means "in the current folder" — like Bash, PowerShell doesn't run scripts from the current folder by name alone, for security.

Execution policy (Windows)

On Windows, the execution policy may block scripts:

.\hello.ps1 : File C:\scripts\hello.ps1 cannot be loaded because running scripts is disabled on this system.

Allow your own scripts (and signed downloaded ones) for your user account:

# illustrative
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

• RemoteSigned — scripts you wrote run; scripts downloaded from the internet must be signed (or unblocked with Unblock-File). It's the default on Windows Server and a sensible choice for workstations.
• The execution policy is a safety feature against accidents, not a security boundary.
• On Linux and macOS, there's no execution policy.

Running on Linux and macOS

Add a shebang line to run a script directly:

# illustrative
#!/usr/bin/env pwsh
Write-Output "Hello from PowerShell on Linux"

Then chmod +x hello.ps1 and ./hello.ps1.

Dot-sourcing

Running a script normally keeps its variables and functions to itself. Dot-sourcing it (. .\helpers.ps1, with a dot and a space) runs it in the current scope, so its functions stay available — a simple way to load helper functions.

Common mistakes

• Double-clicking a .ps1 file on Windows opens it in Notepad, by design. Run scripts from a terminal.
• Setting the execution policy to Unrestricted or Bypass globally to "fix" errors. RemoteSigned for the current user is enough.