Struct Cli 

pub struct Cli { /* private fields */ }

A program CLI. Register options and arguments before parsing; registration errors panic.

Implementations

impl Cli

pub fn new() -> Cli

A CLI named after argv[0], rooted at the current directory, reading the process environment.

pub fn name(&mut self, name: &str) -> &mut Self

Program name shown in usage.

pub fn root(&mut self, root: &str) -> &mut Self

Base directory for default/env path values and search dirs (relative to cwd).

pub fn cwd(&mut self, cwd: &str) -> &mut Self

Directory command-line paths are relative to.

pub fn env<I: IntoIterator<Item = (String, String)>>( &mut self, env: I, ) -> &mut Self

Replace the environment options are read from.

pub fn description(&mut self, text: &str) -> &mut Self

Set the description below the usage line and return this CLI.

pub fn epilog(&mut self, text: &str) -> &mut Self

Set the final help text and return this CLI.

pub fn effects(&mut self, effects: &[&str]) -> &mut Self

What running the program does: read-only, idempotent, destructive, network.

pub fn stdin(&mut self, description: &str, content_type: &str) -> &mut Self

What the program reads on stdin; content_type is a MIME type or a comma-separated list.

pub fn stdout(&mut self, description: &str, content_type: &str) -> &mut Self

What the program writes on stdout; undeclared means text.

pub fn exclusive(&mut self, longs: &[&str]) -> &mut Self

At most one of these options may be given.

pub fn requires(&mut self, long: &str, longs: &[&str]) -> &mut Self

When long is given, the others must be too.

pub fn one_of(&mut self, longs: &[&str]) -> &mut Self

At least one of these options must be given.

pub fn command(&mut self, name: &str, description: &str) -> &mut Cli

Register a command (spec section 1.7) and return it, to register its options and arguments on.

pub fn command_path(&self) -> Vec<String>

The command words selected by the last parse, e.g. ["db", "migrate"].

pub fn config(&mut self, option: &str, prefixes: &str) -> &mut Self

option holds the config file path; prefixes is comma-separated.

pub fn require_command( &mut self, command: &str, description: &str, install_hint: &str, ) -> &mut Self

Require an executable on PATH when parsing, with a description and optional installation hint.

pub fn path_search(&mut self, long: &str, dirs: &str) -> &mut Self

Fallback dirs (colon-separated, relative to root) for bare relative values of a path option.

pub fn opt( &mut self, var: &str, long: &str, short: &str, default: &str, description: &str, ) -> OptRef<'_>

Register an option. default is a value, “flag”, “optional”, or “” (required).

pub fn opt_array( &mut self, var: &str, long: &str, short: &str, description: &str, ) -> OptRef<'_>

Register a repeatable option whose values accumulate into a list.

pub fn arg( &mut self, name: &str, description: &str, default: &str, rule: &str, ) -> ArgRef<'_>

Register a positional argument. An empty default makes it required.

pub fn arg_variadic( &mut self, name: &str, description: &str, rule: &str, ) -> ArgRef<'_>

Register a final positional argument that collects all remaining tokens.

pub fn parse<S: AsRef<str>>(&mut self, argv: &[S]) -> Parsed

Parse without exiting. Values are available via Cli::values when the result is Parsed::Ok.

pub fn run(&mut self) -> Values

Parse std::env::args() like a CLI: handles –help, –help-json-schema and –bash-completion, prints errors and exits on failure. Returns the values.

pub fn run_with<S: AsRef<str>>(&mut self, argv: &[S]) -> Values

Cli::run with explicit arguments (excluding the program name).

pub fn values(&self) -> &Values

Read resolved values from the last successful parse.

pub fn source(&self, long: &str) -> &'static str

Where an option’s value came from: cli, config, env, default or unset.

pub fn is_set(&self, long: &str) -> bool

Whether an option came from the command line.

pub fn is_explicitly_set(&self, long: &str) -> bool

Whether an option came from CLI, config, or environment rather than a default.

pub fn values_json(&self) -> String

Resolved values as JSON (spec section 10).

pub fn usage(&mut self) -> String

Help text (spec section 7), for the selected command.

pub fn json_schema(&mut self) -> String

JSON description of the CLI (spec section 8).

pub fn completion_script(&self, shell: &str) -> Option<String>

Shell script that enables completion for this program (spec section 9): eval "$(prog --completion bash)". None for an unknown shell.

pub fn completion_data(&mut self) -> String

Tab-separated completion records (spec section 9).

pub fn completion_data_for(&mut self, words: &[&str]) -> String

Completion records for the words typed after the program name: a program with commands follows them (spec section 9).

Trait Implementations

impl Clone for Cli

fn clone(&self) -> Cli

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Cli

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Cli

fn default() -> Self

Returns the “default value” for a type.