Struct Tool 

pub struct Tool {
    pub name: &'static str,
    pub verb: &'static str,
    pub section: u8,
    pub about: &'static str,
    pub usage_exit: u8,
    pub command: fn() -> Command,
    pub run: fn(&ArgMatches) -> Result<Outcome, CliError>,
}

One dotted name, and the program behind it.

Fields

name: &'static str

The name it is installed and invoked under: mkfs.<fs>.

verb: &'static str

The word that selects it after the repository name: rust-fs-<fs> mkfs ....

section: u8

Its manual section: 8 for mkfs.* and fsck.*, 1 otherwise.

about: &'static str

One line for the repository’s help.

usage_exit: u8

The exit status of a wrong command line: 2 by the shared contract, but a tool whose name promises another scheme keeps that scheme’s (fsck.* answers 16, as fsck(8) documents, because 2 there means “reboot”).

command: fn() -> Command

Its arguments. The name and version are set by the caller.

run: fn(&ArgMatches) -> Result<Outcome, CliError>

Run it. Ok is printed on stdout in the format asked for; Err as a structured error on stderr, with its code as the exit status.