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README.md
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@ -8,55 +8,271 @@ just
Commands are stored in a file called `justfile` with a syntax inspired by `make`:
```make
# test everything. must build first
test-all: build
test --all
./test --all
# run a specific test by passing it as an argument: `just test server-test`
test TEST: build
test --test {{TEST}}
./test --test {{TEST}}
# build the binary
build:
cc *.c -o main
version = "0.2.0"
tardir = "awesomesauce-" + version
tarball = tardir + ".tar.gz"
build-tarball:
rm -f {{tarball}}
mkdir {{tardir}}
cp README.md *.c {{tardir}}
tar zcvf {{tarball}} {{tardir}}
rm -rf {{tardir}}
publish: test build-tarball
scp {{tarball}} me@server.com:release/
# recipes can be written in any language
serve-docs:
#!/usr/bin/env python3
import os, http.server, socketserver
PORT = 8000
Handler = http.server.SimpleHTTPRequestHandler
os.chdir('docs')
httpd = socketserver.TCPServer(("", PORT), Handler)
print("serving at port", PORT)
httpd.serve_forever()
```
`just` avoids `make`'s idiosyncrasies and produces excellent error messages, so debugging a `justfile` is easier and less suprising than debugging a makefile.
`just` produces detailed error messages and avoids `make`'s idiosyncrasies, so debugging a justfile is easier and less suprising than debugging a makefile.
If you need help with `just` please feel free to send me an email. Feature requests and bug reports are always welcome!
getting started
---------------
`just` should run on any system with a reasonable `sh`, and can be installed with `cargo`, the [rust language](https://www.rust-lang.org) package manager:
`just` should run on any system with a reasonable `sh` and can be installed with `cargo`, the [rust language](https://www.rust-lang.org) package manager;
1. Get rust and cargo from [rustup.rs](https://www.rustup.rs)
2. Run `cargo install just`
3. Add `~/.cargo/bin` to your PATH
Then, create a file called `justfile` in the root of your project and start adding recipes to it.
Optionally, you can `alias j=just` for lighting fast command running.
How do I just?
--------------
Once `just` is working, create a file called `justfile` in the root of your project and start adding recipes to it.
Recipes look like this:
```make
recipe-name:
echo 'This is a recipe!'
another-recipe:
@echo 'Another recipe.'
```
Running `just` with no arguments runs the first recipe in the `justfile`:
```sh
$ just
echo 'This is a recipe!'
This is a recipe!
```
When you invoke `just` it looks for a `justfile` in the current directory and upwards, so you can invoke `just` from any subdirectory of your project.
One or more arguments specify the recipes to run:
```sh
$ just another-recipe
Another recipe.
```
`just` prints each command to standard error before running it, which is why `echo 'This is a recipe!'` was printed. Lines starting with `@` will not be printed which is whyc `echo 'Another recipe.'` was not. printed.
Recipes stop running if a command fails. Here `cargo publish` will only run if `cargo test` succeeds:
```make
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`:
```make
build:
cc main.c foo.c bar.c -o main
test: build:
./test
sloc:
@echo "`wc -l *.c` lines of code"
```
```sh
$ 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:
```sh
$ 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:
```sh
$ just test build
cc main.c foo.c bar.c -o main
./test
testing... all tests passed!
```
Assignment, strings, concatination, and substitution with `{{...}}` are supported:
```make
version = "0.2.7"
tardir = "awesomesauce-" + version
tarball = tardir + ".tar.gz"
publish:
rm -f {{tarball}}
mkdir {{tardir}}
cp README.md *.c {{tardir}}
tar zcvf {{tarball}} {{tardir}}
scp {{tarball}} me@server.com:release/
rm -rf {{tarball}} {{tardir}}
```
Recipes may take arguments. Here recipe `build` takes an argument called `target`:
```make
build target:
@echo 'Building {{target}}...'
cd {{target}} && make
```
Only one recipe that takes arguments may given on the command line, and other recipes may not depend on it. To pass arguments put them after the recipe name:
```sh
$ just build my-awesome-project
Building my-awesome-project...
cd my-awesome-project && make
```
Variables can be exported to recipes as environment variables:
```make
export RUST_BACKTRACE = "1"
test:
# will print a stack trace if it crashes
cargo test
```
Backticks can be used to store the result of commands:
```make
localhost = `dumpinterfaces | cut -d: -f2 | sed 's/\/.*//' | sed 's/ //g'
serve:
./serve {{localhost}} 8080
```
Recipes that start with a `#!` are executed as scripts, so you can write recipes in other languages:
```make
polyglot: python js perl sh ruby
python:
#!/usr/bin/env python3
print('Hello from python!')
js:
#!/usr/bin/env node
console.log('Greetings from JavaScript!')
perl:
#!/usr/bin/env perl
print "Larry Wall says Hi!\n";
sh:
#!/usr/bin/env sh
hello='Yo'
echo "$hello from a shell script!"
ruby:
#!/usr/bin/env ruby
puts "Hello from ruby!"
```
```sh
$ just polyglot
Hello from python!
Greetings from JavaScript!
Larry Wall says Hi!
Yo from a shell script!
Hello from ruby!
```
`just` also supports a number of useful command line options for listing, dumping, and debugging recipes and variable:
```sh
$ just --list
js perl polyglot python ruby
$ just --show perl
perl:
#!/usr/bin/env perl
print "Larry Wall says Hi!\n";
$ just --show polyglot
polyglot: python js perl sh ruby
```
Run `just --help` to see all the options.
miscellanea
-----------
### syntax hilighting
`justfile` syntax is close enough to `make` that you may want to tell your editor to use make syntax hilighting for just.
For vim, you can put the following in `~/.vim/filetype.vim`:
```vimscript
if exists("did_load_filetypes")
finish
endif
augroup filetypedetect
au BufNewFile,BufRead justfile setf make
augroup END
```
If you use another editor, feel free to send me the commands necessary to get syntax hilighting working and send them to me, so that I may include them here.
### justfile grammar
A description of the grammar of justfiles can be found in [](grammar.md).
### just.sh
Before `just` was a bloated rust program it was a tiny shell script. If you would rather not or can't install rust you can find the old shellscript in [](extras/just.sh). This version uses `make`, so it may not be portable across systems.
further ramblings
-----------------
`just` is a trivial program, but I personally find it very useful to write a `justfile` for almost every project, big or small.
On a big projects with multiple contributers, it's very useful to have a file with all the commands needed to work on the project close at hand.
There are probably different commands to test, build, lint, deploy, and the like, and having them all in one place is useful and cuts down on the time you have to spend telling people which commands to run and how to type them.
And, with an easy place to put commands, it's likely that you'll come up with other useful things which are part of the project's collective wisdom, but which aren't written down anywhere, like the arcane commands needed for some part of your revision control workflow, install all your project's dependencies, or all the random flags you might need to pass to the build system.
Some ideas for recipes:
* Deploying/publishing the project
* Building in release mode vs debug mode
* Running in debug mode or with logging enabled
* Complex git workflows
* Updating dependencies
* Running different sets of tests, for example fast tests vs slow tests, or running them with verbose output
* Any complex set of commands that you really should write down somewhere, if only to be able to remember them
Even for small, personal projects it's nice to be able to remember commands by name instead of `^R`everse searching my shell history, and it is a huge boon to be able to go into an old project written in a random language with a mysterious build system and know that all the commands you need to do whatever you need to do are in the `justfile`, and that if you type `just` something useful (or at least interesting!) will probably happen.
I hope you enjoy using `just`, and find great success and satisfaction in all your computational endeavors!
😸

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justfile
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@ -13,8 +13,6 @@ build:
check:
cargo check
nop:
publish: clippy build
# make sure version is up to date
git diff --no-ext-diff --quiet --exit-code

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notes
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@ -1,52 +1,7 @@
todo
----
should justfile recipes have arguments or parameters?
After that, the sky is the limit!
Ideas for recipes include:
* Deploying/publishing the project
* Building in release mode vs debug mode
* Running in debug mode/with logging enabled
* Complex git workflows
* Updating dependencies
* Running different sets of tests, for example fast tests vs slow tests
* Any complex set of commands that you really should write down somewhere, if only to be able to remember them
. start with an short example justfile
. recipes, dependencies, assignments, backticks
. make this justfile runnable as a test
. users can email me or open an issue for help, bowing emoji
open issue for feature requests
. ask users to contribute their justfiles as tests
. make it clear it's beta, mention that, as a command runner
there is probably a higher than normal chance of disaster
. installation instructions with cargo or rustup
. vim and emacs syntax hilighting (use makefile syntax hilighting for now)
- command line flags
- advanced recipes
. long example justfile, make runnable as a script
. very low friction to write a script (no new file, chmod, add to rcs)
. `` strips a single newline
. note that exports do not affect backticks in assignments
. polyglot recipes + habit of using clever commands and writing little scripts
. note that shell is invoked with -u
. update tarball dep
. clean
. update logs (repetitive git flow)
. check version string
. quine
. link to grammar.md
. mention extras/just.sh
- extract anything between ``` in readme as a justfile and make sure it parses
. alias .j='just --justfile ~/.justfile --working-directory ~'
@ -57,46 +12,3 @@ Ideas for recipes include:
. irc
. r/rust
. hacker news
how it works
------------
`just` can then be invoked from any subdirectory of your project.
The first recipe in the `justfile` will be run when `just` is invoked with no arguments, which makes it a good candidate for the command that you run most often, for example building and testing your project. Other recipes can be run by supplying their name as an argument, for example `just build` to run the `build` recipe.
- recipes stop if a command fails
- commands are printed before running unless prepended with @
With no arguments `just` runs the default recipe:
`just`
Adding one argument specifies the recipe:
`just compile`
Multiple recipes can be run in order:
`just lint compile test`
Arguments after `--` are exported to environment variables`ARG0`, `ARG1`, ..., `ARGN`, which can be used in the justfile. To run recipe `compile` and export `ARG0=bar` and `ARG1=baz`:
`just compile -- bar baz`
further ramblings
-----------------
`just` is a trivial program, but I personally find it enormously useful and write a `justfile` for almost every project, big or small.
For one, `just` is a full 5 characters shorter than `./main`, and 3 characters shorter than `make`.
On a big project with multiple contributers, it's very useful to have a file with all the commands needed to work on the project. There are probably different commands to test, build, lint, deploy, and the like, and having them all in one place is useful and cuts down on the time you have to spend telling people which commands to run and how to type them. And, with an easy place to put commands, it's likely that you'll come up with other useful things which are part of the project's collective wisdom, but which aren't written down anywhere, like the arcane commands needed for your project's revision control workflow, for updating dependencies, or all the random flags you might need to pass to the build system.
Even for small, personal projects, it's nice to be able to go into an old project written in some random language with some mysterious build system and know that all the commands you need to do whatever you need to do are in the justfile, and that if you type `just` something useful will probably happen.
If you have a feature request, do open an issue and let me know.
I hope you enjoy using `just`, and find great success and satisfaction in all your computational endeavors!
😸