Powershell Windows

Name: Powershell Windows
Author: sickn33

sickn33/antigravity-awesome-skills

2.3k installs
44k repo stars
Updated July 27, 2026
sickn33/antigravity-awesome-skills

powershell-windows is a community skill for Windows PowerShell syntax pitfalls, null checks, and script templates.

About

PowerShell Windows Patterns documents critical syntax and reliability rules for Windows PowerShell scripts. Operator rules require parentheses around each cmdlet call when combining with -or or -and, because bare Test-Path chains parse incorrectly. Unicode and emoji are banned in scripts; use ASCII markers like [OK], [!], and [WARN] instead. Null checks must guard before accessing Count or Length on possibly empty variables. String interpolation should store complex property paths in variables before embedding in strings. Error handling guidance sets ErrorActionPreference per environment, avoids returning inside try blocks, and uses finally for cleanup. File paths prefer Join-Path with environment variables for cross-platform safety on Windows. JSON operations mandate ConvertTo-Json -Depth 10 for nested objects and UTF8 encoding on Out-File. A script template enables Set-StrictMode, Continue preference, Split-Path script directory resolution, and exit codes in catch blocks. Common error table maps parameter or, unexpected token, and null property failures to fixes.

Wrap cmdlet calls in parentheses when using -or and -and operators.
Use ASCII-only status markers; no emoji or Unicode in scripts.
Guard null before accessing Count or Length on variables.
Always pass -Depth 10 to ConvertTo-Json for nested objects.
Use Join-Path instead of hard-coded Windows path concatenation.

Powershell Windows by the numbers

2,326 all-time installs (skills.sh)
+34 installs in the week ending Jul 28, 2026 (Skillselion tracking)
Ranked #81 of 560 CLI & Terminal skills by installs in the Skillselion catalog
Security screen: LOW risk (skills.sh audit)
Data as of Jul 28, 2026 (Skillselion catalog sync)

At a glance

powershell-windows capabilities & compatibility

Capabilities: logical operator parentheses rules · ascii only output conventions · null safe property access patterns · join path and json depth guidance · try catch script template with exit codes
Use cases: devops · debugging
Platforms: Windows
Runs: Runs locally
Pricing: Free

From the docs

What powershell-windows says it does

Each cmdlet call MUST be in parentheses when using logical operators.

SKILL.md

npx skills add https://github.com/sickn33/antigravity-awesome-skills --skill powershell-windows

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Installs	2.3k
repo stars	★ 44k
Security audit	3 / 3 scanners passed
Last updated	July 27, 2026
Repository	sickn33/antigravity-awesome-skills ↗

Why does my PowerShell if statement fail with parameter 'or' or null property errors?

Write reliable Windows PowerShell scripts with correct operators, null checks, paths, and JSON depth handling.

Who is it for?

Writing or reviewing Windows PowerShell automation and agent-generated scripts.

Skip if: Skip for bash-only Linux workflows or PowerShell Core cross-platform modules without Windows specifics.

When should I use this skill?

User writes PowerShell on Windows or hits operator, Unicode, or JSON depth errors.

What you get

Scripts following parentheses, ASCII, null-safe, and Join-Path conventions with reliable JSON output.

Corrected `.ps1` scripts
Operator-safe conditional expressions

Files

SKILL.mdMarkdownGitHub ↗

PowerShell Windows Patterns

Critical patterns and pitfalls for Windows PowerShell.

---

1. Operator Syntax Rules

CRITICAL: Parentheses Required

❌ Wrong	✅ Correct
`if (Test-Path "a" -or Test-Path "b")`	`if ((Test-Path "a") -or (Test-Path "b"))`
`if (Get-Item $x -and $y -eq 5)`	`if ((Get-Item $x) -and ($y -eq 5))`

Rule: Each cmdlet call MUST be in parentheses when using logical operators.

---

2. Unicode/Emoji Restriction

CRITICAL: No Unicode in Scripts

Purpose	❌ Don't Use	✅ Use
Success	✅ ✓	[OK] [+]
Error	❌ ✗ 🔴	[!] [X]
Warning	⚠️ 🟡	[*] [WARN]
Info	ℹ️ 🔵	[i] [INFO]
Progress	⏳	[...]

Rule: Use ASCII characters only in PowerShell scripts.

---

3. Null Check Patterns

Always Check Before Access

❌ Wrong	✅ Correct
`$array.Count -gt 0`	`$array -and $array.Count -gt 0`
`$text.Length`	`if ($text) { $text.Length }`

---

4. String Interpolation

Complex Expressions

❌ Wrong	✅ Correct
`"Value: $($obj.prop.sub)"`	Store in variable first

Pattern:

$value = $obj.prop.sub
Write-Output "Value: $value"

---

5. Error Handling

ErrorActionPreference

Value	Use
Stop	Development (fail fast)
Continue	Production scripts
SilentlyContinue	When errors expected

Try/Catch Pattern

Don't return inside try block
Use finally for cleanup
Return after try/catch

---

6. File Paths

Windows Path Rules

Pattern	Use
Literal path	`C:\Users\User\file.txt`
Variable path	`Join-Path $env:USERPROFILE "file.txt"`
Relative	`Join-Path $ScriptDir "data"`

Rule: Use Join-Path for cross-platform safety.

---

7. Array Operations

Correct Patterns

Operation	Syntax
Empty array	`$array = @()`
Add item	`$array += $item`
ArrayList add	`$list.Add($item)

---

8. JSON Operations

CRITICAL: Depth Parameter

❌ Wrong	✅ Correct
`ConvertTo-Json`	`ConvertTo-Json -Depth 10`

Rule: Always specify -Depth for nested objects.

File Operations

Operation	Pattern
Read	`Get-Content "file.json" -Raw
Write	`$data

---

9. Common Errors

Error Message	Cause	Fix
"parameter 'or'"	Missing parentheses	Wrap cmdlets in ()
"Unexpected token"	Unicode character	Use ASCII only
"Cannot find property"	Null object	Check null first
"Cannot convert"	Type mismatch	Use .ToString()

---

10. Script Template

# Strict mode
Set-StrictMode -Version Latest
$ErrorActionPreference = "Continue"

# Paths
$ScriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path

# Main
try {
    # Logic here
    Write-Output "[OK] Done"
    exit 0
}
catch {
    Write-Warning "Error: $_"
    exit 1
}

---

Remember: PowerShell has unique syntax rules. Parentheses, ASCII-only, and null checks are non-negotiable.

When to Use

This skill is applicable to execute the workflow or actions described in the overview.

Limitations

Use this skill only when the task clearly matches the scope described above.
Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.