Just

Discovery

just --dump Print justfile
just --evaluate Print variable values
just --help Print detailed command-line syntax help
just --list Print recipes with descriptions
just --show <RECIPE> Print recipe source
just --summary Print recipes without descriptiosn

Execution

just Run default recipe
just <RECIPE> Run specific recipe
just <RECIPE> <ARG1> <ARG2 Run recipe with arguments

Syntax

executable := 'main'

# compile main.c
compile:
  cc main.c -o {{ executable }}

# run main
run: compile
  ./{{ executable }}

# run test
test name: compile
  ./bin/test {{ name }}

# start webserver
serve port='8080':
  python -m http.server {{port}}

# publish current tag
publish:
  #!/usr/bin/env bash
  set -euxo pipefail
  tag=`git describe --tags --exact-match`
  ./bin/check-tag $tag
  git push origin $tag

Notes

The comment proceeding a recipe is used as its doc-comment, and included in just --list.

By default, each line of a recipe runs in a fresh shell. Recipes whose bodies start with #! are written to a file and executed as a script.

Commonly used commands and scripts should be turned into just recipes.