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

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: 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
npm install pkg          → bun install pkg
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
npm i && eslint --fix    → bun i && biome check --write .
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.