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 diff, replace, overwrite, display, coverage, and checkstyle.
56 * `replace` Is the default and overwrites the original files after creating backups of the files.
57 * `overwrite` Overwrites the original files _without_ creating backups.
58 * `display` Will print the formatted files to stdout.
59 * `diff` Will print a diff between the original files and formatted files to stdout.
60 * `checkstyle` Will output the lines that need to be corrected as a checkstyle XML file,
61 that can be used by tools like Jenkins.
63 The write mode can be set by passing the `--write-mode` flag on
64 the command line. For example `rustfmt --write-mode=display src/filename.rs`
66 You can run `rustfmt --help` for more information.
68 `cargo fmt` uses `--write-mode=replace` by default.
71 ## Running Rustfmt from your editor
73 * [Vim](http://johannh.me/blog/rustfmt-vim.html)
74 * [Emacs](https://github.com/fbergroth/emacs-rustfmt)
75 * [Sublime Text 3](https://packagecontrol.io/packages/BeautifyRust)
77 * Visual Studio Code using [RustyCode](https://github.com/saviorisdead/RustyCode) or [vsc-rustfmt](https://github.com/Connorcpu/vsc-rustfmt)
79 ## How to build and test
81 `cargo build` to build.
83 `cargo test` to run all tests.
85 To run rustfmt after this, use `cargo run --bin rustfmt -- filename`. See the
86 notes above on running rustfmt.
89 ## Configuring Rustfmt
91 Rustfmt is designed to be very configurable. You can create a TOML file called
92 rustfmt.toml, place it in the project directory and it will apply the options
93 in that file. See `rustfmt --config-help` for the options which are available,
94 or if you prefer to see source code, [src/config.rs](src/config.rs).
96 By default, Rustfmt uses a style which (mostly) conforms to the
97 [Rust style guidelines](https://github.com/rust-lang/rust/tree/master/src/doc/style).
98 There are many details which the style guidelines do not cover, and in these
99 cases we try to adhere to a style similar to that used in the
100 [Rust repo](https://github.com/rust-lang/rust). Once Rustfmt is more complete, and
101 able to re-format large repositories like Rust, we intend to go through the Rust
102 RFC process to nail down the default style in detail.
104 If there are styling choices you don't agree with, we are usually happy to add
105 options covering different styles. File an issue, or even better, submit a PR.
110 * For things you do not want rustfmt to mangle, use one of
113 #[rustfmt_skip] // requires nightly and #![feature(custom_attribute)] in crate root
114 #[cfg_attr(rustfmt, rustfmt_skip)] // works in stable
116 * When you run rustfmt, place a file named rustfmt.toml in target file
117 directory or its parents to override the default settings of rustfmt.
118 * After successful compilation, a `rustfmt` executable can be found in the