Claude-skill-registry bash-script

Write robust bash scripts with proper error handling. Use when the user says "write a script", "bash script", "shell script", "automate this", "create a backup script", or asks to script a task.

install

source · Clone the upstream repo

git clone https://github.com/majiayu000/claude-skill-registry

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/data/bash-script" ~/.claude/skills/majiayu000-claude-skill-registry-bash-script && rm -rf "$T"

manifest: skills/data/bash-script/SKILL.md

source content

Bash Script

Write robust, maintainable bash scripts with proper error handling.

Instructions

Understand the task requirements
Design the script structure
Write with safety options and error handling
Test and validate

Script template

#!/usr/bin/env bash
set -euo pipefail
IFS=$'\n\t'

# Description: Brief description of what this script does
# Usage: ./script.sh [options] <args>

readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
readonly SCRIPT_NAME="$(basename "${BASH_SOURCE[0]}")"

# Default values
VERBOSE="${VERBOSE:-false}"

usage() {
    cat <<EOF
Usage: ${SCRIPT_NAME} [OPTIONS] <argument>

Description of what the script does.

Options:
    -h, --help      Show this help message
    -v, --verbose   Enable verbose output

Examples:
    ${SCRIPT_NAME} input.txt
    ${SCRIPT_NAME} --verbose /path/to/file
EOF
}

log() {
    echo "[$(date +'%Y-%m-%d %H:%M:%S')] $*" >&2
}

error() {
    log "ERROR: $*"
    exit 1
}

cleanup() {
    # Remove temp files, restore state, etc.
    rm -f "${TEMP_FILE:-}"
}
trap cleanup EXIT

main() {
    # Parse arguments
    while [[ $# -gt 0 ]]; do
        case "$1" in
            -h|--help) usage; exit 0 ;;
            -v|--verbose) VERBOSE=true; shift ;;
            --) shift; break ;;
            -*) error "Unknown option: $1" ;;
            *) break ;;
        esac
    done

    [[ $# -lt 1 ]] && { usage; exit 1; }

    local input="$1"
    [[ -f "$input" ]] || error "File not found: $input"

    # Main logic here
    log "Processing $input"
}

main "$@"

Safety options explained

Option	Purpose
`set -e`	Exit on error
`set -u`	Error on undefined variables
`set -o pipefail`	Pipeline fails if any command fails
`IFS=$'\n\t'`	Safer word splitting

Best practices

MUST use
```
set -euo pipefail
```
at script start
MUST quote all variables:
```
"$var"
```
not
```
$var
```
MUST use
```
[[
```
for conditionals (not
```
[
```
)
MUST use
```
$()
```
for command substitution (not backticks)
Use
```
readonly
```
for constants
Use
```
local
```
for function variables
Use
```
trap
```
for cleanup
Use
```
mktemp
```
for temp files

Common patterns

# Check if command exists
command -v docker &>/dev/null || error "docker not found"

# Default value
name="${1:-default}"

# Read file line by line
while IFS= read -r line; do
    echo "$line"
done < "$file"

# Process arguments
for arg in "$@"; do
    echo "$arg"
done

# Temp file with cleanup
TEMP_FILE="$(mktemp)"
trap 'rm -f "$TEMP_FILE"' EXIT

Rules

MUST include
```
set -euo pipefail
```
MUST quote all variable expansions
MUST include usage function for scripts with arguments
MUST use trap for cleanup of temp files
Never use
```
eval
```
with user input
Never assume current directory
Always use absolute paths for cron scripts