-# rustfmt [](https://travis-ci.org/rust-lang-nursery/rustfmt) [](https://ci.appveyor.com/api/projects/status/github/rust-lang-nursery/rustfmt)
+# rustfmt [](https://travis-ci.org/rust-lang-nursery/rustfmt) [](https://ci.appveyor.com/project/nrc/rustfmt) [](https://crates.io/crates/rustfmt-nightly)
A tool for formatting Rust code according to style guidelines.
## Quick start
-You must be using a nightly compiler toolchain.
+You must be using the latest nightly compiler toolchain.
To install:
or if you're using [Rustup](https://www.rustup.rs/)
```
+rustup update
rustup run nightly cargo install rustfmt-nightly
```
binary and library targets of your crate.
You'll probably want to specify the write mode. Currently, there are modes for
-diff, replace, overwrite, display, coverage, and checkstyle.
+`diff`, `replace`, `overwrite`, `display`, `coverage`, `checkstyle`, and `plain`.
-* `replace` Is the default and overwrites the original files after creating backups of the files.
-* `overwrite` Overwrites the original files _without_ creating backups.
+* `overwrite` Is the default and overwrites the original files _without_ creating backups.
+* `replace` Overwrites the original files after creating backups of the files.
* `display` Will print the formatted files to stdout.
+* `plain` Also writes to stdout, but with no metadata.
* `diff` Will print a diff between the original files and formatted files to stdout.
Will also exit with an error code if there are any differences.
* `checkstyle` Will output the lines that need to be corrected as a checkstyle XML file,
The write mode can be set by passing the `--write-mode` flag on
the command line. For example `rustfmt --write-mode=display src/filename.rs`
-`cargo fmt` uses `--write-mode=replace` by default.
+`cargo fmt` uses `--write-mode=overwrite` by default.
If you want to restrict reformatting to specific sets of lines, you can
use the `--file-lines` option. Its argument is a JSON array of objects
If `rustfmt` successfully reformatted the code it will exit with `0` exit
status. Exit status `1` signals some unexpected error, like an unknown option or
a failure to read a file. Exit status `2` is returned if there are syntax errors
-in the input files. `rustfmt` can't format syntatically invalid code. Finally,
+in the input files. `rustfmt` can't format syntactically invalid code. Finally,
exit status `3` is returned if there are some issues which can't be resolved
automatically. For example, if you have a very long comment line `rustfmt`
doesn't split it. Instead it prints a warning and exits with `3`.
rustfmt to exit with an error code if the input is not formatted correctly.
It will also print any found differences.
-(These instructions use the Syntex version of Rustfmt. If you want to use the
-nightly version replace `install rustfmt` with `install rustfmt-nightly`,
-however you must then only run this with the nightly toolchain).
+(These instructions use the nightly version of Rustfmt. If you want to use the
+Syntex version replace `install rustfmt-nightly` with `install rustfmt`).
A minimal Travis setup could look like this:
cache: cargo
before_script:
- export PATH="$PATH:$HOME/.cargo/bin"
-- which rustfmt || cargo install rustfmt
+- which rustfmt || cargo install rustfmt-nightly
script:
- cargo fmt -- --write-mode=diff
- cargo build
visual style previews, [Configurations.md](Configurations.md).
By default, Rustfmt uses a style which conforms to the [Rust style guide][style
-guide]. For details that have not yet been formalized through the [style RFC
-process][fmt rfcs], we try to adhere to a style similar to that used in the
-[Rust repo][rust].
+guide] that has been formalized through the [style RFC
+process][fmt rfcs].
-If there are styling choices you don't agree with, we are usually happy to add
-options covering different styles. File an issue, or even better, submit a PR.
+Configuration options are either stable or unstable. Stable options can always
+be used, while unstable ones are only available on a nightly toolchain, and opt-in.
+See [Configurations.md](Configurations.md) for details.
## Tips
```
* When you run rustfmt, place a file named `rustfmt.toml` or `.rustfmt.toml` in
target file directory or its parents to override the default settings of
- rustfmt.
+ rustfmt. You can generate a file containing the default configuration with
+ `rustfmt --dump-default-config rustfmt.toml` and customize as needed.
* After successful compilation, a `rustfmt` executable can be found in the
target directory.
* If you're having issues compiling Rustfmt (or compile errors when trying to
install), make sure you have the most recent version of Rust installed.
+* If you get an error like `error while loading shared libraries` while starting
+ up rustfmt you should try the following:
+
+ On Linux:
+
+ ```
+ export LD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$LD_LIBRARY_PATH
+ ```
+
+ On MacOS:
+
+ ```
+ export DYLD_LIBRARY_PATH=$(rustc --print sysroot)/lib:$DYLD_LIBRARY_PATH
+ ```
+
+ On Windows (Git Bash/Mingw):
+
+ ```
+ export PATH=$(rustc --print sysroot)/lib/rustlib/x86_64-pc-windows-gnu/lib/:$PATH
+ ```
+
+ (Substitute `x86_64` by `i686` and `gnu` by `msvc` depending on which version of rustc was used to install rustfmt).
## License
projects / rust.git / blobdiff