Cargo is designed so you can extend it with new subcommands without having to
modify Cargo. If a binary in your
$PATH is named
cargo-something, you can
run it as if it was a Cargo subcommand by running
cargo something. Custom
commands like this are also listed when you run
cargo --list. Being able to
cargo install to install extensions and then run them just like the
built-in Cargo tools is a super convenient benefit of Cargo’s design!
Sharing code with Cargo and crates.io is part of what makes the Rust ecosystem useful for many different tasks. Rust’s standard library is small and stable, but crates are easy to share, use, and improve on a timeline different from that of the language. Don’t be shy about sharing code that’s useful to you on crates.io; it’s likely that it will be useful to someone else as well!