1 # rustfmt [![Build Status](https://travis-ci.org/rust-lang-nursery/rustfmt.svg)](https://travis-ci.org/rust-lang-nursery/rustfmt)
3 A tool for formatting Rust code according to style guidelines.
5 If you'd like to help out (and you should, it's a fun project!), see
6 [Contributing.md](Contributing.md).
16 to run on a cargo project in the current working directory:
24 > **Note:** this method currently requires you to be running cargo 0.6.0 or
31 or if you're using [`multirust`](https://github.com/brson/multirust)
34 multirust run nightly cargo install rustfmt
37 Usually cargo-fmt, which enables usage of Cargo subcommand `cargo fmt`, is
38 installed alongside rustfmt. To only install rustfmt run
41 cargo install --no-default-features rustfmt
46 You can run Rustfmt by just typing `rustfmt filename` if you used `cargo
47 install`. This runs rustfmt on the given file, if the file includes out of line
48 modules, then we reformat those too. So to run on a whole module or crate, you
49 just need to run on the root file (usually mod.rs or lib.rs). Rustfmt can also
50 read data from stdin. Alternatively, you can use `cargo fmt` to format all
51 binary and library targets of your crate.
53 You'll probably want to specify the write mode. Currently, there are modes for
54 replace, overwrite, display, and coverage. The replace mode is the default
55 and overwrites the original files after renaming them. In overwrite mode,
56 rustfmt does not backup the source files. To print the output to stdout, use the
57 display mode. The write mode can be set by passing the `--write-mode` flag on
60 `rustfmt filename --write-mode=display` prints the output of rustfmt to the
63 You can run `rustfmt --help` for more information.
65 `cargo fmt` uses `--write-mode=replace` by default.
68 ## Running Rustfmt from your editor
70 * [Vim](http://johannh.me/blog/rustfmt-vim.html)
71 * [Emacs](https://github.com/fbergroth/emacs-rustfmt)
72 * [Sublime Text 3](https://packagecontrol.io/packages/BeautifyRust)
76 ## How to build and test
78 First make sure you've got Rust **1.4.0** or greater available, then:
80 `cargo build` to build.
82 `cargo test` to run all tests.
84 To run rustfmt after this, use `cargo run --bin rustfmt -- filename`. See the
85 notes above on running rustfmt.
88 ## What style does Rustfmt use?
90 Rustfmt is designed to be very configurable. You can create a TOML file called
91 rustfmt.toml, place it in the project directory and it will apply the options
92 in that file. See `cargo run -- --config-help` for the options which are available,
93 or if you prefer to see source code, [src/config.rs].
95 By default, Rustfmt uses a style which (mostly) conforms to the
96 [Rust style guidelines](https://github.com/rust-lang/rust/tree/master/src/doc/style).
97 There are many details which the style guidelines do not cover, and in these
98 cases we try to adhere to a style similar to that used in the
99 [Rust repo](https://github.com/rust-lang/rust). Once Rustfmt is more complete, and
100 able to re-format large repositories like Rust, we intend to go through the Rust
101 RFC process to nail down the default style in detail.
103 If there are styling choices you don't agree with, we are usually happy to add
104 options covering different styles. File an issue, or even better, submit a PR.
109 * For things you do not want rustfmt to mangle, use one of
113 #[cfg_attr(rustfmt, rustfmt_skip)]
115 * When you run rustfmt, place a file named rustfmt.toml in target file
116 directory or its parents to override the default settings of rustfmt.
117 * After successful compilation, a `rustfmt` executable can be found in the