Struct args::Args

pub struct Args { /* fields omitted */ }

A dead simple implementation of command line argument parsing and validation.

Methods

impl Args

fn new(program_name: &str, description: &str) -> Args

Creates an empty set of command line options.

fn flag(&mut self, short_name: &str, long_name: &str, desc: &str) -> &mut Args

Registers an optional flag argument that does not take an argument and defaults to false.

• short_name - e.g. "h" for a -h option, or "" for none
• long_name - e.g. "help" for a --help option, or "" for none
• desc - A description of the flag for the usage message

fn full_usage(&self) -> String

Generates a combination of the short and verbose usage messages.

fn has_options(&self) -> bool

Returns a bool indicating whether or not any options are registered.

fn has_value(&self, opt_name: &str) -> bool

Returns a bool indicating whether or not a argument is present.

fn iter(&self) -> Iter<String, String>

Returns an iterator visiting all key-value pairs in alphabetical order.

fn option(
    &mut self,
    short_name: &str,
    long_name: &str,
    desc: &str,
    hint: &str,
    occur: Occur,
    default: Option<String>
) -> &mut Args

Registers an option explicitly.

• short_name - e.g. "h" for a -h option, or "" for none
• long_name - e.g. "help" for a --help option, or "" for none
• desc - A description of the flag for the usage message
• hint - A hint to be used in place of the argument in the usage message, e.g. "FILE" for a -o FILE option
• occur - An enum representing whether the option is required or not
• default - The default value for this option if there should be one

fn parse<C: IntoIterator>(&mut self, raw_args: C) -> Result<(), ArgsError> where
    C::Item: AsRef<OsStr>, 

Parses arguments according to the registered options.

Failures

Fails if any errors are encountered during parsing.

fn parse_from_cli(&mut self) -> Result<(), ArgsError>

Parses arguments directly from the command line according to the registered options.

Failures

Fails if any errors are encountered during parsing.

fn short_usage(&self) -> String

Generates a one-line usage summary from the registered options.

fn usage(&self) -> String

Generates a verbose usage summary from the registered options.

fn optional_validated_value_of<T>(
    &self,
    opt_name: &str,
    validations: &[Box<Validation<T = T>>]
) -> Result<Option<T>, ArgsError> where
    T: FromStr, 

Retrieves the optional value of the Opt identified by opt_name, casts it to the type specified by T, runs all provided Validations, and wraps it in an Option.

Failures

See validated_value_of

fn optional_value_of<T: FromStr>(
    &self,
    opt_name: &str
) -> Result<Option<T>, ArgsError>

Retrieves the optional value of the Opt identified by opt_name, casts it to the type specified by T and wraps it in an optional.

Failures

See value_of

fn validated_value_of<T>(
    &self,
    opt_name: &str,
    validations: &[Box<Validation<T = T>>]
) -> Result<T, ArgsError> where
    T: FromStr, 

Retrieves the value of the Opt identified by opt_name, casts it to the type specified by T and then runs all provided Validations.

Failures

Returns Err(ArgsError) if no Opt correspond to opt_name, if the value cannot be cast to type T or if any validation is considered invalid.

fn value_of<T: FromStr>(&self, opt_name: &str) -> Result<T, ArgsError>

Retrieves the value for the Opt identified by opt_name and casts it to the type specified by T.

Failures

Returns Err(ArgsError) if no Opt corresponds to opt_name or if the value cannot be cast to type T.

fn values_of<T: FromStr>(&self, opt_name: &str) -> Result<Vec<T>, ArgsError>

Retrieves a vector of values for the Opt identified by opt_name and casts each of them to the type specified by T.

Failures

Returns Err(ArgsError) if no Opt corresponds to opt_name or if any of the values cannot be cast to type T.

Trait Implementations

impl Display for Args

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

Formats the value using the given formatter.