Master of defensive Bash scripting for production automation, CI/CD pipelines, and system utilities. Expert in safe, portable, and testable shell scripts.
SkillScore86Maintained
Automatic
◆Coding pack
Last verified 8/29/2026
What it changes
Passed 19 of 22 test cases with the skill, and 18 of 22 without it.
Without skill82%
With skill86%
Checks it passed that the model alone missed
Applies set -Eeuo pipefail for strict error handling
Enables inherit_errexit via shopt for subshell error propagation
Handles command line arguments through standard option parsing routines
and 2 more in the full report
2 fixed17 passed either way2 still failing1 broke
Pass-rate lift
+5 pp
Tokens
+100%
Agent turns
0%
Response time
+21%
Model gemini-3.6-flashMeasured 8/29/2026v119 of 22 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 2 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 2
Prompt
Our deployment shell script fails silently when intermediate commands fail or when input filenames contain spaces. Could you rewrite it into a hardened, portable Bash script with proper option parsing, strict error handling, safe variable handling, and inline header documentation?
What was checked, without and with the skill
Checked
Without skill
With skill
Applies set -Eeuo pipefail for strict error handling
Missed
Passed
Resolves the physical canonical script directory path avoiding symlink issues
Missed
Passed
case-02 · gemini-3.6-flash · 8/29/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md221 linessingle file
Use this skill when
Writing or reviewing Bash scripts for automation, CI/CD, or ops
Hardening shell scripts for safety and portability
Do not use this skill when
You need POSIX-only shell without Bash features
The task requires a higher-level language for complex logic
You need Windows-native scripting (PowerShell)
Instructions
Define script inputs, outputs, and failure modes.
Apply strict mode and safe argument parsing.
Implement core logic with defensive patterns.
Add tests and linting with Bats and ShellCheck.
Safety
Treat input as untrusted; avoid eval and unsafe globbing.
Prefer dry-run modes before destructive actions.
Focus Areas
Defensive programming with strict error handling
POSIX compliance and cross-platform portability
Safe argument parsing and input validation
Robust file operations and temporary resource management
Process orchestration and pipeline safety
Production-grade logging and error reporting
Comprehensive testing with Bats framework
Static analysis with ShellCheck and formatting with shfmt
Modern Bash 5.x features and best practices
CI/CD integration and automation workflows
Approach
Always use strict mode with set -Eeuo pipefail and proper error trapping
Quote all variable expansions to prevent word splitting and globbing issues
Master binary analysis patterns including disassembly, decompilation, control flow analysis, and code pattern recognition. Use when analyzing executables, understanding compiled code, or performing static analysis on binaries.