Exercise - Scripting - Training

2 minutes

In this unit, you'll use Azure Cloud Shell on the right side of your screen as your Linux terminal. Azure Cloud Shell is a shell you can access through the Azure portal or at https://shell.azure.com. You don't have to install anything on your computer to use it.

First, you'll learn how to set up a profile so you can customize your working environment the way you want it. You'll then write some basic scripts and get a feeling for interpolation and scope.

Set up a profile

A profile is a script that runs when you start a new session. Having a customized environment can make you more productive.

Enter pwsh in a terminal window to start a PowerShell session:
```
pwsh
```

Run this command:

$Profile | Select-Object *

The output will display something similar to this text:

CurrentUserAllHosts                        CurrentUserCurrentHost
-------------------                        ----------------------
/home/<user>/.config/PowerShell/profile.ps1 /home/<user>/.config/PowerShell/Microsoft.…

Create a profile for the current user and the current host by running the command New-Item:
```
New-Item `
  -ItemType "file" `
  -Value 'Write-Host "Hello <replace with your name>, welcome back" -foregroundcolor Green ' `
  -Path $Profile.CurrentUserCurrentHost -Force
```
The -Force switch will overwrite existing content, so be careful if you run this locally and have an existing profile.
Run pwsh to create a new shell. You should now see the following (in green):
```
Hello <your name>, welcome back
```

Create and run a script

Now that you have a profile set up, it's time to create and run a script.

Ensure you have an existing PowerShell session running. In the console window, enter this code:
```
$PI = 3.14
```
Create a file named PI.ps1 in the current directory and open it in your code editor:
```
New-Item -Path . -Name "PI.ps1" -ItemType "file"
code PI.ps1
```
Add the following content to the file and save it. You can use CTRL+S on Windows and Linux or CMD+S on Mac to save your file.
```
$PI = 3
Write-Host "The value of `$PI is now $PI, inside the script"
```
Run the script by specifying the path to it:
```
./PI.ps1
```
Your output displays the following text:
```
The value of $PI is now 3, inside the script
```
Your script does two things. First, it creates a script-local variable $PI that shadows the $PI variable defined in the local scope. Next, the second row in the script interpolates the $PI variable because you used double quotation marks. It escapes interpolation the first time because you used a back tick.
Enter $PI in the console window:
```
3.14
```
The value is still 3.14. The script didn't change the value.

Continue

Exercise - Scripting

Set up a profile

Create and run a script

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