🟢 1️⃣ Basic Script Structure

Create file:

script.ps1

Run:

.\script.ps1

If execution blocked:

Set-ExecutionPolicy RemoteSigned -Scope CurrentUser

---

🟢 2️⃣ Variables

$name = "Yuva"
$age = 25
$isDevOps = $true

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🟢 3️⃣ Parameters (Command Line Arguments)

param(
    [string]$Name,
    [int]$Age
)

Write-Output "Name: $Name"
Write-Output "Age: $Age"

Run:

.\script.ps1 -Name Yuva -Age 25

---

🟢 4️⃣ If / Else

if ($Age -gt 18) {
    Write-Output "Adult"
}
elseif ($Age -eq 18) {
    Write-Output "Exactly 18"
}
else {
    Write-Output "Minor"
}

Operators:

-eq  -ne  -gt  -lt  -ge  -le
-and -or  -not

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🟢 5️⃣ Switch

switch ($Name) {
    "Yuva" { "DevOps Engineer" }
    "Admin" { "System Admin" }
    default { "Unknown" }
}

---

🟢 6️⃣ Loops

For

for ($i=1; $i -le 5; $i++) {
    Write-Output $i
}

Foreach

$items = @("Azure","AWS","GCP")

foreach ($item in $items) {
    Write-Output $item
}

While

$i = 1
while ($i -le 5) {
    Write-Output $i
    $i++
}

---

🟢 7️⃣ Functions

function Add-Numbers {
    param(
        [int]$a,
        [int]$b
    )

    return $a + $b
}

$result = Add-Numbers -a 5 -b 3
Write-Output $result

---

🟢 8️⃣ Arrays

$servers = @("server1","server2","server3")

$servers[0]
$servers.Count

Add:

$servers += "server4"

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🟢 9️⃣ Hashtable (Dictionary)

$user = @{
    Name = "Yuva"
    Role = "DevOps"
    Location = "India"
}

$user["Name"]

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🟢 🔟 Objects

$obj = [PSCustomObject]@{
    Name = "Yuva"
    Role = "DevOps"
}

$obj.Name

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🟢 11️⃣ Reading File Line by Line

Get-Content file.txt | ForEach-Object {
    Write-Output $_
}

---

🟢 12️⃣ Try / Catch (Error Handling)

try {
    Get-Content "notexist.txt"
}
catch {
    Write-Output "File not found"
}
finally {
    Write-Output "Done"
}

Force error catching:

Get-Content test.txt -ErrorAction Stop

---

🟢 13️⃣ Logging to File

$logFile = "log.txt"
Add-Content $logFile "Script started at $(Get-Date)"

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🟢 14️⃣ Checking If File Exists

if (Test-Path "file.txt") {
    Write-Output "File exists"
}

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🟢 15️⃣ Background Job

Start-Job { Get-Process }
Get-Job
Receive-Job -Id 1

---

🟢 16️⃣ REST API Call

$response = Invoke-RestMethod "https://api.github.com"
$response.current_user_url

POST example:

$body = @{
    name = "demo"
} | ConvertTo-Json

Invoke-RestMethod -Uri "https://api.example.com" -Method Post -Body $body -ContentType "application/json"

---

🟢 17️⃣ Working with Services

$service = Get-Service spooler

if ($service.Status -ne "Running") {
    Start-Service spooler
}

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🟢 18️⃣ Scheduled Task (Basic)

Register-ScheduledTask -Action (New-ScheduledTaskAction -Execute "PowerShell.exe" -Argument "C:\script.ps1") -Trigger (New-ScheduledTaskTrigger -Daily -At 9am) -TaskName "MyTask"

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🟢 19️⃣ Script Template (Production Style)

Copy this template:

param(
    [string]$Environment = "dev"
)

$ErrorActionPreference = "Stop"

function Write-Log {
    param([string]$Message)
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    Add-Content "app.log" "$timestamp - $Message"
}

try {
    Write-Log "Script started for $Environment"

    if (-not (Test-Path "config.json")) {
        throw "Config file missing"
    }

    Write-Log "All checks passed"
}
catch {
    Write-Log "Error: $_"
}
finally {
    Write-Log "Script finished"
}

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🟢 20️⃣ Execution Policy Types

Get-ExecutionPolicy
Set-ExecutionPolicy RemoteSigned

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🟢 21️⃣ Most Used DevOps Commands Inside Scripts

Get-ChildItem
Get-Process
Get-Service
Test-Connection
Invoke-RestMethod
Select-String
Test-Path
Start-Service
Stop-Process

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🔥 DevOps Practical Mini Example

Health check script:

$server = "google.com"

if (Test-Connection $server -Count 2 -Quiet) {
    Write-Output "$server is reachable"
}
else {
    Write-Output "$server is down"
}

---