Enum clap::ErrorKind [] [src]

pub enum ErrorKind {
    InvalidValue,
    UnknownArgument,
    InvalidSubcommand,
    UnrecognizedSubcommand,
    EmptyValue,
    ValueValidation,
    TooManyValues,
    TooFewValues,
    WrongNumberOfValues,
    ArgumentConflict,
    MissingRequiredArgument,
    MissingSubcommand,
    MissingArgumentOrSubcommand,
    UnexpectedMultipleUsage,
    InvalidUtf8,
    HelpDisplayed,
    VersionDisplayed,
    ArgumentNotFound,
    Io,
    Format,
}

Command line argument parser kind of error

Variants

Occurs when an Arg has a set of possible values, and the user provides a value which isn't in that set.

Examples

let result = App::new("prog")
    .arg(Arg::with_name("speed")
        .possible_value("fast")
        .possible_value("slow"))
    .get_matches_from_safe(vec!["prog", "other"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::InvalidValue);

Occurs when a user provides a flag, option, argument or subcommand which isn't defined.

Examples

let result = App::new("prog")
    .arg(Arg::from_usage("--flag 'some flag'"))
    .get_matches_from_safe(vec!["prog", "--other"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::UnknownArgument);

Occurs when the user provides an unrecognized SubCommand which meets the threshold for being similar enough to an existing subcommand. If it doesn't meet the threshold, or the 'suggestions' feature is disabled, the more general UnknownArgument error is returned.

Examples

let result = App::new("prog")
    .subcommand(SubCommand::with_name("config")
        .about("Used for configuration")
        .arg(Arg::with_name("config_file")
            .help("The configuration file to use")
            .index(1)))
    .get_matches_from_safe(vec!["prog", "confi"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::InvalidSubcommand);

Occurs when the user provides an unrecognized SubCommand which either doesn't meet the threshold for being similar enough to an existing subcommand, or the 'sggestions' feature is disabled. Otherwise the more detailed InvalidSubcommand error is returned.

This error typically happens when passing additional subcommand names to the help subcommand. Otherwise, the more general UnknownArgument error is used.

Examples

let result = App::new("prog")
    .subcommand(SubCommand::with_name("config")
        .about("Used for configuration")
        .arg(Arg::with_name("config_file")
            .help("The configuration file to use")
            .index(1)))
    .get_matches_from_safe(vec!["prog", "help", "nothing"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::UnrecognizedSubcommand);

Occurs when the user provides an empty value for an option that does not allow empty values.

Examples

let res = App::new("prog")
    .arg(Arg::with_name("color")
         .long("color")
         .empty_values(false))
    .get_matches_from_safe(vec!["prog", "--color="]);
assert!(res.is_err());
assert_eq!(res.unwrap_err().kind, ErrorKind::EmptyValue);

Occurs when the user provides a value for an argument with a custom validation and the value fails that validation.

Examples

fn is_numeric(val: String) -> Result<(), String> {
    match val.parse::<i64>() {
        Ok(..) => Ok(()),
        Err(..) => Err(String::from("Value wasn't a number!")),
    }
}

let result = App::new("prog")
    .arg(Arg::with_name("num")
         .validator(is_numeric))
    .get_matches_from_safe(vec!["prog", "NotANumber"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::ValueValidation);

Occurs when a user provides more values for an argument than were defined by setting Arg::max_values.

Examples

let result = App::new("prog")
    .arg(Arg::with_name("arg")
        .multiple(true)
        .max_values(2))
    .get_matches_from_safe(vec!["prog", "too", "many", "values"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::TooManyValues);

Occurs when the user provides fewer values for an argument than were defined by setting Arg::min_values.

Examples

let result = App::new("prog")
    .arg(Arg::with_name("some_opt")
        .long("opt")
        .min_values(3))
    .get_matches_from_safe(vec!["prog", "--opt", "too", "few"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::TooFewValues);

Occurs when the user provides a different number of values for an argument than what's been defined by setting Arg::number_of_values or than was implicitly set by Arg::value_names.

Examples

let result = App::new("prog")
    .arg(Arg::with_name("some_opt")
        .long("opt")
        .takes_value(true)
        .number_of_values(2))
    .get_matches_from_safe(vec!["prog", "--opt", "wrong"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::WrongNumberOfValues);

Arg::number_of_values

Occurs when the user provides two values which conflict with each other and can't be used together.

Examples

let result = App::new("prog")
    .arg(Arg::with_name("debug")
        .long("debug")
        .conflicts_with("color"))
    .arg(Arg::with_name("color")
        .long("color"))
    .get_matches_from_safe(vec!["prog", "--debug", "--color"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::ArgumentConflict);

Occurs when the user does not provide one or more required arguments.

Examples

let result = App::new("prog")
    .arg(Arg::with_name("debug")
        .required(true))
    .get_matches_from_safe(vec!["prog"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::MissingRequiredArgument);

Occurs when a subcommand is required (as defined by AppSettings::SubcommandRequired), but the user does not provide one.

Examples

let err = App::new("prog")
    .setting(AppSettings::SubcommandRequired)
    .subcommand(SubCommand::with_name("test"))
    .get_matches_from_safe(vec![
        "myprog",
    ]);
assert!(err.is_err());
assert_eq!(err.unwrap_err().kind, ErrorKind::MissingSubcommand);

Occurs when either an argument or SubCommand is required, as defined by AppSettings::ArgRequiredElseHelp, but the user did not provide one.

Examples

let result = App::new("prog")
    .setting(AppSettings::ArgRequiredElseHelp)
    .subcommand(SubCommand::with_name("config")
        .about("Used for configuration")
        .arg(Arg::with_name("config_file")
            .help("The configuration file to use")))
    .get_matches_from_safe(vec!["prog"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::MissingArgumentOrSubcommand);

Occurs when the user provides multiple values to an argument which doesn't allow that.

Examples

let result = App::new("prog")
    .arg(Arg::with_name("debug")
        .long("debug")
        .multiple(false))
    .get_matches_from_safe(vec!["prog", "--debug", "--debug"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::UnexpectedMultipleUsage);

Occurs when the user provides a value containing invalid UTF-8 for an argument and AppSettings::StrictUtf8 is set.

Platform Speicific

Non-Windows platforms only (such as Linux, Unix, OSX, etc.)

Examples

let result = App::new("prog")
    .setting(AppSettings::StrictUtf8)
    .arg(Arg::with_name("utf8")
        .short("u")
        .takes_value(true))
    .get_matches_from_safe(vec![OsString::from("myprog"),
                                OsString::from("-u"),
                                OsString::from_vec(vec![0xE9])]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::InvalidUtf8);

Not a true "error" as it means --help or similar was used. The help message will be sent to stdout.

Note: If the help is displayed due to an error (such as missing subcommands) it will be sent to stderr instead of stdout.

Examples

let result = App::new("prog")
    .get_matches_from_safe(vec!["prog", "--help"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::HelpDisplayed);

Not a true "error" as it means --version or similar was used. The message will be sent to stdout.

Examples

let result = App::new("prog")
    .get_matches_from_safe(vec!["prog", "--version"]);
assert!(result.is_err());
assert_eq!(result.unwrap_err().kind, ErrorKind::VersionDisplayed);

Occurs when using the value_t! and values_t! macros to convert an argument value into type T, but the argument you requested wasn't used. I.e. you asked for an argument with name config to be converted, but config wasn't used by the user.

Represents an I/O error. Can occur when writing to stderr or stdout or reading a configuration file.

Represents a Format error. Typically caused by writing to stderr or stdout.

Trait Implementations

impl Debug for ErrorKind
[src]

Formats the value using the given formatter.

impl Copy for ErrorKind
[src]

impl Clone for ErrorKind
[src]

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

impl PartialEq for ErrorKind
[src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.