bash-defensive-patterns
Build safer Bash scripts
Write Bash scripts that fail safely and are easier to debug. This skill provides defensive patterns for errors, inputs, and cleanup.
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Test it
Using "bash-defensive-patterns". Explain how to add strict mode and cleanup to my script
Expected outcome:
- Enable strict mode with set -Eeuo pipefail
- Add an ERR trap that prints the failing line
- Create a temp directory with mktemp -d
- Use an EXIT trap to remove the temp directory
Using "bash-defensive-patterns". How do I safely parse command line arguments in Bash
Expected outcome:
- Use a while loop with case statements for option parsing
- Quote all variables including $1 and $2
- Validate required arguments after parsing
- Show usage help for -h or unknown options
Using "bash-defensive-patterns". Show me a safe way to run background tasks
Expected outcome:
- Store PIDs in an array when starting background jobs
- Create a cleanup function that sends SIGTERM to tracked PIDs
- Trap SIGTERM and SIGINT to call cleanup
- Use wait to join all background processes
Security Audit
SafePure documentation skill containing only instructional markdown and code examples. No executable scripts, file system access, network calls, or data collection capabilities. Content matches stated purpose of teaching defensive Bash programming patterns. All 116 static findings are FALSE POSITIVES - the flagged patterns are the TOPIC being taught, not malicious code.
Risk Factors
🌐 Network access (4)
📁 Filesystem access (9)
⚙️ External commands (78)
Quality Score
What You Can Build
Harden CI scripts
Apply strict mode, traps, and safe file handling to reduce pipeline failures.
Safer maintenance scripts
Build idempotent system scripts with logging and cleanup patterns.
Reliable utilities
Add input validation and dry run support to team utilities.
Try These Prompts
Create a Bash script header with strict mode, error traps, and a cleanup handler for temporary files.
Show a robust argument parser with --verbose, --dry-run, and --output, plus validation.
Provide safe move and safe delete functions with clear error messages.
Give a pattern to start background jobs, track PIDs, and cleanly stop on SIGTERM.
Best Practices
- Enable strict mode and inherit ERR traps
- Quote all variables and validate inputs
- Use traps for cleanup and clear error messages
Avoid
- Using unquoted variables in file operations
- Ignoring command failures in pipelines
- Overwriting files without existence checks
Frequently Asked Questions
Is this compatible with macOS and Linux?
Does it support POSIX sh?
Can I integrate this into CI pipelines?
Does it access my files or secrets?
What if strict mode breaks my script?
How does this compare to a linter?
Developer Details
Author
wshobsonLicense
MIT
Repository
https://github.com/wshobson/agents/tree/main/plugins/shell-scripting/skills/bash-defensive-patternsRef
main
File structure
📄 SKILL.md