When should I use bash-script-writing?

bash-script-writing is useful in the following scenarios: • Case 1: Generating robust system administration scripts with integrated logging and fail-fast error handling. • Case 2: Refactoring legacy, monolithic shell scripts into modular, reusable functions for better maintainability. • Case 3: Creating standardized CI/CD pipeline scripts that require clear execution flows and descriptive status reporting. • Case 4: Developing professional CLI utilities with built-in argument parsing, help menus, and color-coded console output.

When & Why to Use This Skill

This Claude skill provides a professional framework for generating production-ready Bash scripts. It emphasizes modern scripting best practices, including strict error handling (set -euo pipefail), modular function architecture, and standardized documentation headers. By automating the creation of clean and maintainable shell code, it helps developers and DevOps engineers eliminate silent failures and build reliable automation tools that are easy to debug and scale.

Use Cases

Case 1: Generating robust system administration scripts with integrated logging and fail-fast error handling.
Case 2: Refactoring legacy, monolithic shell scripts into modular, reusable functions for better maintainability.
Case 3: Creating standardized CI/CD pipeline scripts that require clear execution flows and descriptive status reporting.
Case 4: Developing professional CLI utilities with built-in argument parsing, help menus, and color-coded console output.

name	bash-script-writing
description	Write clean, modular, production-ready bash scripts with proper error handling and maintainable structure. Use when creating new shell scripts, refactoring existing bash code, or when user asks for bash/shell scripting help with terms like "write a script", "bash script", "shell script", or "automate with bash".

Modular Bash Script Writing

Write bash scripts with clear structure, proper error handling, and modular functions.

Core Principles

Strict mode: Start with set -euo pipefail
Functions over monoliths: One function per logical operation
Document at top: Header with purpose, usage, configuration
Fail fast with clarity: Descriptive errors with fix suggestions

Script Structure

Place main() immediately after variables so workflow is visible at file top.

#!/usr/bin/env bash
set -euo pipefail

################################################################################
# Script Title
################################################################################
#
# OVERVIEW
# --------
# Brief description of what this script does
#
# USAGE
# -----
#   script-name arg1 arg2
#
# CONFIGURATION
# -------------
# Environment variables or config requirements
#
################################################################################

# Colors
green='\033[0;32m'
blue='\033[0;34m'
yellow='\033[1;33m'
red='\033[0;31m'
nc='\033[0m'

# Configuration
VAR_ONE=${VAR_ONE:-default}
VAR_TWO=${VAR_TWO:?VAR_TWO is required}

################################################################################
# Main Orchestration
################################################################################

main() {
  parse_arguments "$@"
  step_one
  step_two
  log "Complete!"
}

################################################################################
# Helper Functions
################################################################################

log() { echo -e "${green}==>${nc} ${1}"; }
info() { echo -e "${blue}Info:${nc} ${1}"; }
warn() { echo -e "${yellow}Warning:${nc} ${1}"; }
error() { echo -e "${red}Error:${nc} ${1}" >&2; exit 1; }

################################################################################
# Core Functions
################################################################################

function_name() {
  log "What this function does..."
  # Implementation
  log "Complete"
}

################################################################################
# Script Execution
################################################################################

main "$@"

Function Guidelines

Name clearly: Verb-based names (setup_directory, validate_config)
One purpose: If you need "and" to describe it, split it
Log progress: Start with log "...", end with status
Return codes: return 0 success, return 1 failure
Keep focused: 5-20 lines per function

Error Handling

# Good: Clear error with context
setup_directory() {
  log "Creating deployment directory..."
  if ! ssh "$HOST" "mkdir -p /app/deploy"; then
    error "Failed to create directory on $HOST"
  fi
  log "Directory ready"
}

# Bad: Silent failure
setup_directory() {
  ssh "$HOST" "mkdir -p /app/deploy"
}

Quality Checklist

Strict mode (set -euo pipefail)
Header with overview and usage
Helper functions (log, info, warn, error)
Core logic in named functions
Main() shows clear flow at top
Error messages include context
No silent failures
Meaningful variable names
2-space indentation
Functions grouped with section headers