Bash Defensive Patterns

What it does

The bash-defensive-patterns skill provides a set of best practices and defensive coding techniques for writing robust, secure, and maintainable Bash scripts. It includes strategies to prevent common pitfalls like command injection, improper error handling, and insecure input processing.

When to use it

• Writing Bash scripts that interact with user inputs or external data sources.
• Developing scripts that require high security and reliability in production environments.
• Ensuring scripts are resilient against unexpected failures or malicious attacks.
• Improving the maintainability of long-term Bash projects by following consistent coding standards.

Key capabilities

• Input validation and sanitization techniques
• Safe use of command substitution and variable expansion
• Error handling with traps and exit codes
• Secure execution of external commands using "$@" and quoting strategies
• Prevention of shell injection vulnerabilities

Example prompts

• "How can I safely handle user input in a Bash script to prevent command injection?"
• "What are the best practices for error handling in Bash scripts?"
• "Can you show me how to use defensive patterns when executing external commands in Bash?"

Tips & gotchas

• Always quote variables and use "$@" instead of $* to avoid unintended word splitting.
• Test scripts with edge cases, such as inputs containing spaces or special characters, to ensure robustness.