usbrelay-rs is both an executable binary that can be run, and a library that can be used in Rust programs.
Installing the sainsmart executable
Assuming you have Rust/Cargo installed, run this command in a terminal:
cargo install usbrelay-rs
It will make the sainsmart command available in your PATH if you've allowed the PATH to be modified when installing Rust. cargo uninstall usbrelay-rs uninstalls.
Adding usbrelay_rs library as a dependency
Run this command in a terminal, in your project's directory:
cargo add usbrelay-rs
To add it manually, edit your project's Cargo.toml file and add to the [dependencies] section:
usbrelay-rs = "0.1.0"
The usbrelay_rs library will be automatically available globally.
Read the usbrelay_rs library documentation.