Quick Start
See the installation section for how to install just on your
computer. Try running just --version to make sure that it’s installed
correctly.
For an overview of the syntax, check out this cheatsheet.
Once just is installed and working, create a file named justfile in the
root of your project with the following contents:
recipe-name:
echo 'This is a recipe!'
# this is a comment
another-recipe:
@echo 'This is another recipe.'
When you invoke just it looks for file justfile in the current directory
and upwards, so you can invoke it from any subdirectory of your project.
The search for a justfile is case insensitive, so any case, like Justfile,
JUSTFILE, or JuStFiLe, will work. just will also look for files with the
name .justfile, in case you’d like to hide a justfile.
Running just with no arguments runs the first recipe in the justfile:
$ just
echo 'This is a recipe!'
This is a recipe!
One or more arguments specify the recipe(s) to run:
$ just another-recipe
This is another recipe.
just prints each command to standard error before running it, which is why
echo 'This is a recipe!' was printed. This is suppressed for lines starting
with @, which is why echo 'This is another recipe.' was not printed.
Recipes stop running if a command fails. Here cargo publish will only run if
cargo test succeeds:
publish:
cargo test
# tests passed, time to publish!
cargo publish
Recipes can depend on other recipes. Here the test recipe depends on the
build recipe, so build will run before test:
build:
cc main.c foo.c bar.c -o main
test: build
./test
sloc:
@echo "`wc -l *.c` lines of code"
$ just test
cc main.c foo.c bar.c -o main
./test
testing… all tests passed!
Recipes without dependencies will run in the order they’re given on the command line:
$ just build sloc
cc main.c foo.c bar.c -o main
1337 lines of code
Dependencies will always run first, even if they are passed after a recipe that depends on them:
$ just test build
cc main.c foo.c bar.c -o main
./test
testing… all tests passed!