# Just — A Modern Command Runner and Makefile Alternative

> Just is a command runner, like Make but for modern dev workflows. Write recipes in a Justfile, run them with `just recipe-name`. Simpler syntax than Make, no obscure behaviors, cross-platform, and works great for project tasks.

## Install

Save as a script file and run:

## Quick Use

```bash
# Install
brew install just                           # macOS
cargo install just                          # Rust
scoop install just                          # Windows
```

Create `justfile` in your project root:
```make
# List recipes
default:
  @just --list

# Run tests
test:
  npm test

# Build for production
build:
  npm run build
  @echo "Build complete"

# Deploy with arg
deploy env="staging":
  ./scripts/deploy.sh {{env}}

# Multi-line recipe
release version:
  git tag v{{version}}
  git push --tags
  cargo publish

# Recipe with dependencies
ci: test build
  echo "CI passed"
```

Run:
```bash
just              # default recipe
just test         # run tests
just deploy prod  # with argument
just ci           # runs test then build then echo
```

## Intro

Just is a command runner, inspired by Make but built for modern developer workflows. Written in Rust by Casey Rodarmor, it offers cleaner syntax, cross-platform support, and avoids Make quirks (tab-only indentation, .PHONY gotchas, shell escaping). Perfect for project task automation.

- **Repo**: https://github.com/casey/just
- **Stars**: 32K+
- **Language**: Rust
- **License**: CC0 (public domain)

## What Just Does

- **Recipes** — named task definitions in a justfile
- **Arguments** — positional and named with defaults
- **Dependencies** — recipes can depend on other recipes
- **Shebang recipes** — run entire recipe with python/node/bash
- **String interpolation** — `{{var}}` substitution
- **Env vars** — dotenv support via `set dotenv-load`
- **Conditional** — `if os == "macos" { ... }`
- **Private recipes** — prefix with `_`
- **Groups** — organize recipes into groups

## Architecture

Parses the justfile, builds a DAG of recipes, and runs them via the configured shell (sh by default, or any shebang). No make-style file timestamps or incremental logic — simpler and more predictable.

## Self-Hosting

Single Rust binary.

## Key Features

- Modern clean syntax
- Cross-platform (macOS, Linux, Windows)
- Recipe arguments with defaults
- Dependencies and groups
- Shebang recipes for multi-language tasks
- Env var integration
- Nice error messages
- `just --list` auto-help
- Tab or space indentation

## Comparison

| Tool | Language | Scope | Strengths |
|---|---|---|---|
| Just | Rust | Task runner | Simple modern syntax |
| Make | C | Build + tasks | Ubiquitous, incremental |
| Taskfile | Go | Task runner | YAML-based |
| npm scripts | JS | Node projects | Built into npm |
| mise tasks | Rust | Task runner | Integrated env manager |
| cargo-make | Rust | Rust projects | Rust-focused |

## 常见问题 FAQ

**Q: 和 Make 区别？**
A: Just 不做增量构建（无文件时间戳追踪），专注于任务运行。语法更干净，无 tab 强制、无 .PHONY 坑。适合 project tasks，不适合 C/C++ 大型构建。

**Q: 可以在 CI 用吗？**
A: 非常合适。CI 上 `just ci` 一行跑所有检查，开发者本地完全一样的体验。

**Q: 支持 include 吗？**
A: 支持 `import` 语法（v1.14+）来复用 recipes。

## 来源与致谢 Sources

- Docs: https://just.systems
- GitHub: https://github.com/casey/just
- License: CC0

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Source: https://tokrepo.com/en/workflows/d3b6480b-35cb-11f1-9bc6-00163e2b0d79
Author: Script Depot