Hands-On Microservices with Rust

Parsing arguments

Similar to the examples in the previous chapter, we have a parser for arguments. It has the following declaration:

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("FILE")        .help("Sets a file name of a database")        .takes_value(true),        )    .subcommand(SubCommand::with_name(CMD_ADD).about("add user to the table")                .arg(Arg::with_name("NAME")                     .help("Sets the name of a user")                     .required(true)                     .index(1))                .arg(Arg::with_name("EMAIL")                     .help("Sets the email of a user")                     .required(true)                     .index(2))) .subcommand(SubCommand::with_name(CMD_LIST).about("prints a list ...