# rustup doc

> Open the offline Rust documentation for the current toolchain.
> There are a lot more documentation pages not mentioned here. See `rustup help doc` for more information.
> More information: <https://rust-lang.github.io/rustup>.

- Open the main page:

`rustup doc`

- Open the documentation for a specific topic (a module in the standard library, a type, a keyword, etc.):

`rustup doc {{std::fs|usize|fn|...}}`

- Open the Rust Programming Language book:

`rustup doc --book`

- Open the Cargo book:

`rustup doc --cargo`

- Open the Rust Reference:

`rustup doc --reference`
