Installing and Using Rust

This guide explains how to install Rust, a popular programming language designed to maximize performance and safety. It also discusses how to create, compile, and run a simple Rust project. Rust is somewhat similar to C++, although it is able to guarantee memory and thread safety. Rust was originally developed for use at Mozilla Research, but it has recently gained in popularity throughout the software industry. For many years now, Rust has been rated one of the top programming languages in industry surveys.

Before You Begin

1. Familiarize yourself with our Getting Started guide and complete the steps for setting your Linode’s hostname and timezone.

2. This guide uses sudo wherever possible. Complete the sections of Linode’s Securing Your Server to create a standard user account, harden SSH access and remove unnecessary network services. Do not follow the Configure a Firewall section yet–this guide includes firewall rules specifically for an OpenVPN server.

3. Update the system:

   sudo apt-get update && sudo apt-get upgrade
   

Note

This guide is written for a non-root user. Commands that require elevated privileges are prefixed with sudo. For information about the sudo command, see the Users and Groups guide.

Advantages of the Rust Programming Language

Rust runs as quickly as C++ does, but is safer to use. This is because it emphasizes memory and thread safety through the use of a borrow checker and reference validation. Unlike many memory-safe languages, Rust does not use a garbage collector, which means it is relatively memory efficient. Rust allows direct access to the hardware layer and control over the memory layout. This makes it a good choice for embedded systems. It is suitable for highly concurrent systems and for applications requiring large-system integrity. Rust includes a library that allows for calls to, or from, C++ with very little overhead.

Installing Rust

The typical, and most straightforward, way to install Rust is by using rustup. This is Rust’s main installation program and version manager. These instructions are designed for Ubuntu, but are generally applicable to most Linux distributions.

Note

To experiment with Rust before downloading it, try the Rust Playground. This is an open source educational program that allows beginners to write and run simple Rust programs.

1. Download rustup, which manages the Rust download process.

   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
   

   Note

   For those who do not want to use curl, it is also possible to download rustup-init directly. A list of all the versions of rustup-init can be found on Rust’s installation methods page. For Ubuntu systems, select thex86_64-unknown-linux-gnu file.

2. Rust displays some background details about the installation, including the location of default directories and environmental settings for its various components. It then provides the following three choices:

   1) Proceed with installation (default)
   2) Customize installation
   3) Cancel installation

3. In most cases, customization is not required. To accept the defaults and proceed with the installation, enter 1. To customize the Rust installation, first carefully review the information about the various settings and note any necessary changes. Then enter 2 to begin the customization process.

   When the process is complete, Rust confirms the installation is successful.

   Rust is installed now. Great!

4. To apply the environment changes, either source the Rust env file or log in to a new console session. Then verify the correct version of Rust has been installed by using the version flag.

   source $HOME/.cargo/env
   rustc --version
   

   You should see a similar output:

   rustc 1.50.0 (cb75ad5db 2021-02-10)

5. If the version command still does not work, manually add the ~/.cargo/bin directory to the PATH variable in ~/.bashrc. Source the .bashrc file and try the command again.

   File: ~/.bashrc

   1 2 3 4

   ... export PATH="$HOME/.cargo/bin:$PATH" ...

Note

It is also possible to use Git to install Rust. Clone the Rust GitHub repository and run cargo run --release. See the rustup installation page for more information.

Updating or Uninstalling Rust

1. To update Rust, use the rustup tool.

   rustup update
   

2. To remove Rust from your system, run the following command.

   rustup self uninstall
   

Using Rust

Rust support is available for many editors, including Vi/Vim, VS Code, and Emacs.

Building a Small Project in Rust

As with most programming languages, it is easiest to learn the basics with a simple “Hello, World” program. This short tutorial explains how to create, write, compile, and run a program in Rust. Compiling and running a program are separate steps. A program must be compiled before it can run.

1. Create a directory named projects to store all of your Rust projects. Then, create a sub-directory for the “Hello World” project and move into the new directory.

   mkdir ~/projects
   cd ~/projects
   mkdir hello
   cd hello
   

2. Create a new source file named hello.rs inside the hello directory. All Rust files must end with the .rs extension.

   touch hello.rs
   

3. Open the hello.rs file in a text editor, and add the code required to display “Hello, World!” to the main function. The main function is the first code to execute in any Rust project. Here are a few things to note about this program:

   • Parentheses () are used to enclose any function parameters. There are no parameters in this case.
   • The body of the function is enclosed inside curly braces {}.
   • Inside the function, println! is a macro that sends text to the standard output device. The ! symbol at the end of the macro name means println is a macro and not an actual function.
   • The arguments passed to println are contained inside the trailing parentheses. Here there is only one parameter, which contains the text to be printed.
   • Each expression ends with a ; symbol.

   Consult Rust’s documentation for further discussion of Rust’s style conventions.

   File: ~/projects/hello/hello.rs

   1 2 3 4

   fn main() { println!("Hello, world!"); }

4. Save and close the hello.rs file.

5. Compile the program using the rustc compiler. Provide the name of the file as an argument to rustc. This creates an executable named hello. The name of the executable is the name of the source file containing the main routine, minus the .rs extension.

   rustc hello.rs
   

6. Run the program from the hello directory by specifying the name of the executable.

   ./hello
   

   Provided there are no errors, the program displays “Hello, world!” in the console window. If the program does not work as expected, verify the syntax of the hello.rs file is correct.

   Hello, world!

Using the Cargo Build Tool and Package Manager

The lightweight process in the previous section works well with small applications because it imposes no extra overhead. For larger applications with dependencies, it is preferable to use Cargo, Rust’s build tool and package manager. Cargo, which is installed by rustup alongside Rust, can be used to simplify many common development tasks. The following examples demonstrate some of Cargo’s functionality.

1. Confirm Cargo is installed and verify the version number using the version flag.

   cargo --version
   

   cargo 1.50.0 (f04e7fab7 2021-02-04)

2. Create a new project using the new command. The following example indicates how to create a project named cargo_project.

   cargo new cargo_project
   

3. Compile and build a project, linking in any dependencies, using the build command.

   cargo build
   

4. Compile, build, and run any Rust project using the run command. If the source code has not changed since the last build, the compile and build steps are skipped.

   cargo run
   

5. To use Cargo to test a Rust project, run the following command.

   cargo test
   

6. Use Cargo to build documentation for a project using the doc command.

   cargo doc
   

7. Publish a package to the Crates repository using the publish command.

   cargo publish
   

For Further Reference

The Rust website provides extensive documentation, including tutorials, examples, and a link to the Rust Programming Language text. In particular, the Rustlings Course serves as a good quick introduction to the language. The short tutorial at the bottom of the Getting Started page is also useful. The Rust documentation also contains guides to the Cargo package manager and the rustc compiler.

More Information

You may wish to consult the following resources for additional information on this topic. While these are provided in the hope that they will be useful, please note that we cannot vouch for the accuracy or timeliness of externally hosted materials.

• Rust Programming Language