Hands-On Microservices with Rust

Parsing arguments

Since our command supports three subcommands, we have to add them to a clap::App instance:

let matches = App::new(crate_name!())    .version(crate_version!())    .author(crate_authors!())    .about(crate_description!())    .setting(AppSettings::SubcommandRequired)    .arg(        Arg::with_name("database")        .short("d")        .long("db")        .value_name("ADDR")        .help("Sets an address of db connection")        .takes_value(true),        )    .subcommand(SubCommand::with_name(CMD_ADD).about("add a session")                .arg(Arg::with_name("TOKEN")                     .help("Sets the token of a user")                     .required(true)                     .index(1))                .arg(Arg::with_name("UID")                     .help("Sets the uid of a user")                     .required(true)                     .index(2)))    .subcommand(SubCommand::with_name(CMD_REMOVE).about("remove a session") .arg(Arg::with_name("TOKEN") ...