Shell Scripting & CLI
Review Checklist
Bash Fundamentals
#!/usr/bin/env bash
set -euo pipefail # exit on error, undefined vars, pipe failures
# Logging
log() { echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" >&2; }
# Safe temp directory
tmpdir=$(mktemp -d)
trap "rm -rf '$tmpdir'" EXIT
# Argument parsing
while [[ $# -gt 0 ]]; do
case "$1" in
--name) NAME="$2"; shift 2 ;;
--verbose) VERBOSE=1; shift ;;
--help) usage; exit 0 ;;
*) log "ERROR: Unknown option: $1"; exit 1 ;;
esac
done
# Safe file write (atomic)
echo "$content" > "$file.tmp" && mv "$file.tmp" "$file"
# Check command exists
command -v docker &>/dev/null || { log "ERROR: docker not found"; exit 1; }
Common Mistakes to Flag
# ❌ Unquoted variable — word splitting and glob expansion
rm -rf $dir/* # if dir is empty, becomes rm -rf /*
# ✅ Always quote
rm -rf "$dir"/*
# ❌ [ ] for conditionals (POSIX, fewer features)
if [ "$a" = "$b" ]; then
# ✅ [[ ]] for bash (more features, safer)
if [[ "$a" == "$b" ]]; then
# ❌ Backticks (can't nest, hard to read)
result=`command`
# ✅ $() for command substitution
result=$(command)
Node.js CLI Tools
// Use commander for arg parsing
import { Command } from 'commander'
const program = new Command()
.name('arena')
.option('-p, --port <number>', 'server port', '3000')
.action((opts) => { startServer(opts.port) })
program.parse()
// Use @clack/prompts for interactive
import { intro, text, confirm, spinner } from '@clack/prompts'
intro('Arena Installer')
const name = await text({ message: 'Agent name?' })
const s = spinner()
s.start('Installing...')
await install()
s.stop('Done!')
// Handle Ctrl+C gracefully
process.on('SIGINT', () => {
cleanup()
process.exit(130)
})
OpenClaw Docker Specifics
# Container name
CONTAINER="openclaw-okny-openclaw-1"
# Run command inside
docker exec "$CONTAINER" bash -c 'openclaw status'
# Config location inside container
# /data/.openclaw/openclaw.json
# Restart
docker compose up -d
# Ports: 18789 (gateway internal), 45133 (proxy external)
Sources
- Google Shell Style Guide
- commander.js documentation
- @clack/prompts documentation
Changelog
- 2026-03-21: Initial skill — shell scripting and CLI
nickgallick