Attribute Macro option

#[option]

Declares a command option.

Any option declaration must contains the name of the argument for example: #[option(name)].

By default any function argument is considered a command option, Use this attribute to provide additional information like arg, alias, description or min, max, default and values arguments.

Options

• name: Name of the option, by default is the function argument name.
• arg: Name of the option argument, by default is the function argument name.
• alias: Alias of the function argument.
• description: Description of the option.
• min: Min number of values the option takes.
• max: Max number of values the option takes.
• default: Default value(s) of the option.
• values: Valid values of the option.
• hidden: If the option is hidden for the help.
• multiple: If the option allow multiple declarations.
• flag: If the option is a bool flag, by default is true
• error: Error show when the value is invalid.
• require_assign: If the option requires to use = to assign the value, by default false,
• global: If the option is global, by default false.
• from_global: If the option is declared as global in a parent, by default false.

Function arguments can be declared as the following types:

• Any type that implement FromStr.
• Vec<T> where T implements FromStr.
• &[T] slices where T implements FromStr.
• Option<T> where T implements FromStr.

Example:

use clapi::macros::*;

#[command]
#[option(repeat, alias="r", default=1)]
#[option(upper_case, alias="u", description="Display the message in uppercase")]
fn main(repeat: u32, upper_case: bool){
    for _ in 0..repeat {
        if upper_case {
            println!("HELLO WORLD");
        } else {
            println!("hello world");
        }
    }
}