Modern Tool Substitution

Replace legacy tools with modern performant alternatives in all generated code.

Core Substitutions

Apply these substitutions unless user explicitly requests the legacy tool:

npm → bun

• npm install → bun install
• npm run → bun run
• npm create → bun create
• npx → bunx
• Scripts remain in package.json unchanged

find → fd

• find . -name '*.py' → fd -e py
• find . -type f -name 'test*' → fd -t f '^test'
• find . -type d → fd -t d
• find . -path '*/node_modules' -prune → fd --exclude node_modules
• Use fd's simpler glob/regex syntax

pip → uv

• pip install pkg → uv pip install pkg
• pip install -r requirements.txt → uv pip install -r requirements.txt
• pip freeze → uv pip freeze
• python -m pip → uv pip
• Virtual envs: uv venv instead of python -m venv

grep → rg

• grep -r pattern → rg pattern
• grep -i pattern → rg -i pattern
• grep -v pattern → rg -v pattern
• grep -l pattern → rg -l pattern
• rg excludes .git, node_modules by default

wget/curl → aria2

• wget URL → aria2c URL
• curl -O URL → aria2c URL
• curl URL → aria2c -d- -o- URL (stdout)
• Multi-connection: aria2c -x16 -s16 URL
• Parallel: aria2c -j5 URL1 URL2 URL3

jq → jaq

• jq '.field' → jaq '.field'
• jq -r '.[]' → jaq -r '.[]'
• jq -c → jaq -c
• jq -s → jaq -s
• Most filters compatible; jaq faster, stricter parsing

eslint/prettier → biome

• eslint . → biome check .
• eslint --fix → biome check --write .
• prettier --write → biome format --write .
• eslint && prettier → biome ci .
• Config: biome.json replaces .eslintrc + .prettierrc

black/flake8/isort → ruff

• black . → ruff format .
• flake8 . → ruff check .
• isort . → ruff check --select I --fix .
• black . && flake8 . && isort . → ruff check --fix . && ruff format .
• Config: ruff.toml or pyproject.toml consolidates all

coreutils → uutils-coreutils

• Drop-in replacement: ls, cat, cp, mv, rm, chmod, etc.
• Install: uu-ls, uu-cat, etc. or multicall binary
• Faster on large operations; Rust safety guarantees
• Syntax identical for common ops

sudo → sudo-rs

• sudo cmd → sudo-rs cmd
• sudo -u user cmd → sudo-rs -u user cmd
• sudo -i → sudo-rs -i
• Drop-in replacement; identical flags
• Rust rewrite; memory-safe vs C sudo

ls → eza

• ls -la → eza -la
• ls -lah → eza -lah
• ls -1 → eza -1
• ls --tree → eza --tree
• Git-aware, colorful, faster on large dirs
• Icons: eza --icons
• Tree view: eza -T or eza --tree

Flag Adaptations

fd syntax:

• Regex by default; globs use -g → fd -g '*.txt'
• Case insensitive: -i
• Fixed strings: -F
• Depth: -d N
• Hidden: -H; no-ignore: -I

rg performance:

• --mmap for large files
• -j$(nproc) parallel
• --sort path when order matters
• --max-count N stop after N

aria2 optimization:

• -x16 -s16 max speed
• -c resume
• --file-allocation=none on SSDs
• --summary-interval=0 reduce output

jaq differences:

• Stricter null handling; use // for null coalescing
• No @base64d (use @base64 | explode | implode)
• Missing some rare filters; document if incompatible

biome vs eslint:

• No plugin system; built-in rules only
• Config minimal: biome.json with linter + formatter sections
• biome migrate eslint converts configs
• Missing custom rules → keep eslint; mention limitation

ruff vs black/flake8:

• 10-100x faster than black
• Combines formatter + linter
• Select rule sets: --select E,F,I (pycodestyle, pyflakes, isort)
• --fix auto-fixes; --unsafe-fixes for aggressive changes
• Missing: complex flake8 plugins → note ruff limitation

uutils performance:

• uu-ls -l faster for huge dirs
• uu-sort parallel by default
• uu-cp shows progress with -v
• 100% compatible for POSIX ops

sudo-rs compatibility:

• Full flag parity with sudo
• Same sudoers config format
• Drop-in binary replacement
• No behavioral changes; security hardened

Edge Cases

bun compatibility:

• Native addons may fail → mention, suggest node fallback

fd vs find:

• -exec → pipe to xargs or fd -x
• -printf → fd output + awk/sed
• Complex boolean → may need find

uv limitations:

• Not for editable installs: uv pip install -e . → keep pip
• Poetry/pipenv → keep; uv is pip replacement only

rg vs grep:

• Binary skip default; rg -a for grep -a
• Symlinks skipped; rg -L to follow
• Multiline: rg -U

aria2 for curl:

• REST APIs → keep curl
• Small file + parse response → keep curl
• Large/parallel downloads → aria2

jaq limitations:

• Missing advanced filters → document, use jq
• Stream processing: jq's --stream not in jaq

biome limitations:

• No plugins → complex rules need eslint
• TypeScript-first; JSX support solid
• Vue/Svelte → keep eslint

ruff limitations:

• Missing niche flake8 plugins → note limitation
• Formatter matches black ~95%; edge cases differ

uutils caveats:

• BSD variants: some flags differ → test
• GNU-specific extensions → check compat

sudo-rs advantages:

• Memory safety vs C sudo
• No historical CVE baggage
• Identical interface; zero migration cost

Exception Handling

Skip substitution when:

• User explicitly names legacy tool
• CI/CD requires specific tool
• Tool unavailable in environment
• Explaining tool differences

Quick Reference

# Package management
bun install pkg          → bun install pkg
uv pip install pandas       → uv pip install pandas

# File operations
find . -name '*.rs'      → fd -e rs
grep -r TODO .           → rg TODO
wget https://x.com/f     → aria2c https://x.com/f

# JSON processing
jq '.data[] | .name'     → jaq '.data[] | .name'
cat file.json | jq -r    → <file.json jaq -r

# Linting/Formatting
eslint --fix .           → biome check --write .
black . && flake8        → ruff check --fix . && ruff format .

# Core utilities
ls -lah                  → uu-ls -lah
cat large.txt            → uu-cat large.txt
sudo systemctl restart   → sudo-rs systemctl restart

# Combined workflows
bun i && eslint --fix    → bun i && biome check --write .
uv pip install -r req.txt   → uv pip install -r req.txt
grep -r TODO | jaq       → rg TODO | jaq
find . -name '*.py'      → fd -e py

Installation Check Pattern

# Graceful fallback pattern
has(){ command -v -- "$1" &>/dev/null; }

# Example: jq/jaq
if has jaq; then
  jaq '.field' file.json
elif has jq; then
  jq '.field' file.json
else
  die "Install jaq (recommended) or jq"
fi

# Example: sudo/sudo-rs
PRIV_CMD=$(has sudo-rs && echo sudo-rs || echo sudo)
$PRIV_CMD systemctl restart service

Apply these substitutions automatically in all code generation unless legacy tool explicitly requested.