Bash Defensive Patterns
CheckedAutomatically applies secure bash scripting patterns to prevent common vulnerabilities like command injection.
Install on your platform
Showing Claude Code. One command installs this skill into any of the agents below.
- 1
Run this in your project
terminal$ npx skills add wshobson/agents --skill bash-defensive-patterns -a claude-code Uses the open-source
skillsCLI and needs Node.js. Add-gto install it for your user instead of this project.
What we know about this skill
Publisher
wshobson
Taken from the source listing. We haven't verified who controls this account.
Install target
Live repository
Not pinned. Installing fetches whatever the repository holds at the time you run the command.
Automated safety checks
This skill passed all 6 checks. We read its files at one commit and looked for the things that make a skill dangerous to run — not for whether it works.
Declares what it does: passed
SKILL.md parses and declares a name and a description.
SKILL.md exists, its frontmatter parses, and it declares a name and a description.
No undeclared network calls: passed
Makes no network calls.
Every host the skill dials — from its scripts, its config endpoints or the commands it tells the agent to run — is either well-known package and API infrastructure or declared in its own frontmatter. Links in documentation are not counted.
No obfuscated payloads: passed
No encoded or obfuscated payloads.
No base64, hex or compressed blob is decoded and then executed, and no encoded shell commands.
No credential access: passed
Reads no keys, tokens, keychains or credential files.
Neither the code nor the SKILL.md instructions read SSH keys, cloud credentials, keychains, token stores, browser cookie databases or dotfiles that hold secrets.
No pipe-to-shell installers: passed
No pipe-to-shell or download-and-run installers.
No `curl … | sh` pattern, in the code or in the instructions, that runs code fetched at run time.
Pinned to a commit: passed
Scanned wshobson/agents at 46891e7e60.
The exact upstream commit SHA that was scanned is recorded, so the result refers to specific bytes.
- Commit
- 46891e7e60
- Scanned
- 2 files, 506 lines
About this skill
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.