Shell Script Validation

This skill provides guidance for validating shell scripts using the comprehensive validation script.

When to Use This Skill

This skill is applicable for:

•Validating shell script before committing
•Running comprehensive script quality checks
•Ensuring syntax correctness
•Verifying best practice compliance

⚠️ CRITICAL: Always Use the Validation Script

DO NOT run individual commands (bash -n, shellcheck) directly.

The validation script handles everything automatically.

Usage

bash

# Run all validations in the workspace
bash shell-script-validation/scripts/validate.sh

# Validate a specific directory
bash shell-script-validation/scripts/validate.sh ./scripts/new_feature/

# Validate a specific script
bash shell-script-validation/scripts/validate.sh ./scripts/deploy.sh

# With verbose output and auto-fix
bash shell-script-validation/scripts/validate.sh -v -f

What the Script Does

The validation script performs all checks in the correct order:

•bash -n - Syntax check without execution
•shellcheck - Comprehensive static analysis and best practice enforcement
•Project standards - Verify script template compliance

Validation Requirements

Before considering scripts complete:

•✅ All validation checks pass
•✅ No syntax errors
•✅ No shellcheck warnings
•✅ Follows project script standards
•✅ Bats tests pass (if applicable)

Validation Workflow

Before Committing

•Make changes - Edit shell scripts

•Run validation:

bash

bash shell-script-validation/scripts/validate.sh ./script.sh

•Fix issues - Address any failures
•
Run tests (if applicable):
bash
```
bats test/*.bats
```
•Commit - Only commit when all checks pass

Common Failures & Quick Fixes

Syntax Errors

code

Error: bash -n failed
script.sh: line 15: syntax error near unexpected token 'fi'

Fix: Correct the syntax error indicated in the message

shellcheck Errors

code

SC2086: Quote variables to prevent word splitting

Fix: Add quotes around variables

bash

# Bad
cd $dir

# Good
cd "$dir" || exit

Common shellcheck Issues

SC2006: Use $(...) instead of backticks

bash

# Bad
result=`command`

# Good
result=$(command)

SC2046: Quote command substitutions

bash

# Bad
for file in $(find . -name "*.txt"); do

# Good
find . -name "*.txt" | while read -r file; do

SC2086: Quote variables

bash

# Bad
echo $var

# Good
echo "$var"

SC2164: Use cd ... || exit

bash

# Bad
cd /some/path

# Good
cd /some/path || exit

Script Standards

Required Template Elements

Every script must include:

bash

#!/bin/bash
# Error handling: exit on error, unset variable, or failed pipeline
set -euo pipefail

# Secure defaults
umask 027
export LC_ALL=C.UTF-8

# Get script directory for library loading
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
export SCRIPT_DIR

# Load all-in-one library
# shellcheck source=../lib/all.sh
# shellcheck disable=SC1091
source "${SCRIPT_DIR}/../lib/all.sh"

Function Order

Functions must be ordered as follows:

•show_usage / parse_arguments (if present)
•Other functions in alphabetical order
•main function last

Troubleshooting

Validation Script Not Found

bash

# Navigate to project root
cd /workspace

# Verify script exists
ls -la .github/skills/shell-script-validation/scripts/validate.sh

# Run with bash explicitly
bash shell-script-validation/scripts/validate.sh

Permission Denied

bash

# Run with bash explicitly
bash shell-script-validation/scripts/validate.sh ./script.sh

Need More Details

For detailed information, see the reference documentation:

•Individual Commands - Detailed command usage for debugging
•Troubleshooting Guide - Comprehensive error resolution
•Script Standards - Project script template and conventions

Quick Reference

Essential Commands

bash

# Full validation
bash shell-script-validation/scripts/validate.sh

# Specific script
bash shell-script-validation/scripts/validate.sh ./script.sh

# With auto-fix
bash shell-script-validation/scripts/validate.sh -f

Validation Checklist

Before committing:

• Validation script passes
• Bats tests pass (if applicable)
• Follows project script standards
• No security issues

Summary

Shell script validation ensures code quality and reliability:

•Always use the validation script - Never run individual commands
•Validate frequently - Run during development, not just before commit
•Follow standards - Use project template and best practices
•Test with Bats - Cover edge cases and errors (if applicable)
•Ensure security - Validate inputs and quote variables
•Never commit invalid scripts - All checks must pass

For detailed debugging and advanced topics, see the reference documentation.