1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440
/// Command line argument parser kind of error
#[derive(Debug, Copy, Clone, PartialEq)]
#[non_exhaustive]
pub enum ErrorKind {
/// Occurs when an [`Arg`][crate::Arg] has a set of possible values,
/// and the user provides a value which isn't in that set.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .arg(Arg::new("speed")
/// .value_parser(["fast", "slow"]))
/// .try_get_matches_from(vec!["prog", "other"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::InvalidValue);
/// ```
InvalidValue,
/// Occurs when a user provides a flag, option, argument or subcommand which isn't defined.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, arg, ErrorKind};
/// let result = Command::new("prog")
/// .arg(arg!(--flag "some flag"))
/// .try_get_matches_from(vec!["prog", "--other"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::UnknownArgument);
/// ```
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
///
#[cfg_attr(not(feature = "suggestions"), doc = " ```no_run")]
#[cfg_attr(feature = "suggestions", doc = " ```")]
/// # use clap::{Command, Arg, ErrorKind, };
/// let result = Command::new("prog")
/// .subcommand(Command::new("config")
/// .about("Used for configuration")
/// .arg(Arg::new("config_file")
/// .help("The configuration file to use")))
/// .try_get_matches_from(vec!["prog", "confi"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::InvalidSubcommand);
/// ```
///
/// [`Subcommand`]: crate::Subcommand
/// [`UnknownArgument`]: ErrorKind::UnknownArgument
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 'suggestions' 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
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind, };
/// let result = Command::new("prog")
/// .subcommand(Command::new("config")
/// .about("Used for configuration")
/// .arg(Arg::new("config_file")
/// .help("The configuration file to use")))
/// .try_get_matches_from(vec!["prog", "help", "nothing"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::UnrecognizedSubcommand);
/// ```
///
/// [`Subcommand`]: crate::Subcommand
/// [`InvalidSubcommand`]: ErrorKind::InvalidSubcommand
/// [`UnknownArgument`]: ErrorKind::UnknownArgument
UnrecognizedSubcommand,
/// Occurs when the user provides an empty value for an option that does not allow empty
/// values.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let res = Command::new("prog")
/// .arg(Arg::new("color")
/// .takes_value(true)
/// .forbid_empty_values(true)
/// .long("color"))
/// .try_get_matches_from(vec!["prog", "--color="]);
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::EmptyValue);
/// ```
EmptyValue,
/// Occurs when the user doesn't use equals for an option that requires equal
/// sign to provide values.
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let res = Command::new("prog")
/// .arg(Arg::new("color")
/// .takes_value(true)
/// .require_equals(true)
/// .long("color"))
/// .try_get_matches_from(vec!["prog", "--color", "red"]);
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::NoEquals);
/// ```
NoEquals,
/// Occurs when the user provides a value for an argument with a custom validation and the
/// value fails that validation.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// fn is_numeric(val: &str) -> Result<(), String> {
/// match val.parse::<i64>() {
/// Ok(..) => Ok(()),
/// Err(..) => Err(String::from("Value wasn't a number!")),
/// }
/// }
///
/// let result = Command::new("prog")
/// .arg(Arg::new("num")
/// .validator(is_numeric))
/// .try_get_matches_from(vec!["prog", "NotANumber"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::ValueValidation);
/// ```
ValueValidation,
/// Occurs when a user provides more values for an argument than were defined by setting
/// [`Arg::max_values`].
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .arg(Arg::new("arg")
/// .max_values(2))
/// .try_get_matches_from(vec!["prog", "too", "many", "values"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::TooManyValues);
/// ```
/// [`Arg::max_values`]: crate::Arg::max_values()
TooManyValues,
/// Occurs when the user provides fewer values for an argument than were defined by setting
/// [`Arg::min_values`].
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .arg(Arg::new("some_opt")
/// .long("opt")
/// .min_values(3))
/// .try_get_matches_from(vec!["prog", "--opt", "too", "few"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::TooFewValues);
/// ```
/// [`Arg::min_values`]: crate::Arg::min_values()
TooFewValues,
/// Occurs when a user provides more occurrences for an argument than were defined by setting
/// [`Arg::max_occurrences`].
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .arg(Arg::new("verbosity")
/// .short('v')
/// .max_occurrences(2))
/// .try_get_matches_from(vec!["prog", "-vvv"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::TooManyOccurrences);
/// ```
/// [`Arg::max_occurrences`]: crate::Arg::max_occurrences()
TooManyOccurrences,
/// 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
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .arg(Arg::new("some_opt")
/// .long("opt")
/// .takes_value(true)
/// .number_of_values(2))
/// .try_get_matches_from(vec!["prog", "--opt", "wrong"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::WrongNumberOfValues);
/// ```
///
/// [`Arg::number_of_values`]: crate::Arg::number_of_values()
/// [`Arg::value_names`]: crate::Arg::value_names()
WrongNumberOfValues,
/// Occurs when the user provides two values which conflict with each other and can't be used
/// together.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .arg(Arg::new("debug")
/// .long("debug")
/// .conflicts_with("color"))
/// .arg(Arg::new("color")
/// .long("color"))
/// .try_get_matches_from(vec!["prog", "--debug", "--color"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::ArgumentConflict);
/// ```
ArgumentConflict,
/// Occurs when the user does not provide one or more required arguments.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .arg(Arg::new("debug")
/// .required(true))
/// .try_get_matches_from(vec!["prog"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
MissingRequiredArgument,
/// Occurs when a subcommand is required (as defined by [`Command::subcommand_required`]),
/// but the user does not provide one.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, ErrorKind};
/// let err = Command::new("prog")
/// .subcommand_required(true)
/// .subcommand(Command::new("test"))
/// .try_get_matches_from(vec![
/// "myprog",
/// ]);
/// assert!(err.is_err());
/// assert_eq!(err.unwrap_err().kind(), ErrorKind::MissingSubcommand);
/// # ;
/// ```
///
/// [`Command::subcommand_required`]: crate::Command::subcommand_required
MissingSubcommand,
/// Occurs when the user provides multiple values to an argument which doesn't allow that.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .arg(Arg::new("debug")
/// .long("debug")
/// .multiple_occurrences(false))
/// .try_get_matches_from(vec!["prog", "--debug", "--debug"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::UnexpectedMultipleUsage);
/// ```
UnexpectedMultipleUsage,
/// Occurs when the user provides a value containing invalid UTF-8.
///
/// To allow arbitrary data
/// - Set [`Arg::allow_invalid_utf8`] for argument values
/// - Set [`Command::allow_invalid_utf8_for_external_subcommands`] for external-subcommand
/// values
///
/// # Platform Specific
///
/// Non-Windows platforms only (such as Linux, Unix, OSX, etc.)
///
/// # Examples
///
#[cfg_attr(not(unix), doc = " ```ignore")]
#[cfg_attr(unix, doc = " ```")]
/// # use clap::{Command, Arg, ErrorKind};
/// # use std::os::unix::ffi::OsStringExt;
/// # use std::ffi::OsString;
/// let result = Command::new("prog")
/// .arg(Arg::new("utf8")
/// .short('u')
/// .takes_value(true))
/// .try_get_matches_from(vec![OsString::from("myprog"),
/// OsString::from("-u"),
/// OsString::from_vec(vec![0xE9])]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::InvalidUtf8);
/// ```
///
/// [`Arg::allow_invalid_utf8`]: crate::Arg::allow_invalid_utf8
/// [`Command::allow_invalid_utf8_for_external_subcommands`]: crate::Command::allow_invalid_utf8_for_external_subcommands
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
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .try_get_matches_from(vec!["prog", "--help"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::DisplayHelp);
/// ```
DisplayHelp,
/// Occurs when either an argument or a [`Subcommand`] is required, as defined by
/// [`Command::arg_required_else_help`] , but the user did not provide
/// one.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind, };
/// let result = Command::new("prog")
/// .arg_required_else_help(true)
/// .subcommand(Command::new("config")
/// .about("Used for configuration")
/// .arg(Arg::new("config_file")
/// .help("The configuration file to use")))
/// .try_get_matches_from(vec!["prog"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::DisplayHelpOnMissingArgumentOrSubcommand);
/// ```
///
/// [`Subcommand`]: crate::Subcommand
/// [`Command::arg_required_else_help`]: crate::Command::arg_required_else_help
DisplayHelpOnMissingArgumentOrSubcommand,
/// Not a true "error" as it means `--version` or similar was used.
/// The message will be sent to `stdout`.
///
/// # Examples
///
/// ```rust
/// # use clap::{Command, Arg, ErrorKind};
/// let result = Command::new("prog")
/// .version("3.0")
/// .try_get_matches_from(vec!["prog", "--version"]);
/// assert!(result.is_err());
/// assert_eq!(result.unwrap_err().kind(), ErrorKind::DisplayVersion);
/// ```
DisplayVersion,
/// Occurs when using the [`ArgMatches::value_of_t`] and friends 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.
///
/// [`ArgMatches::value_of_t`]: crate::ArgMatches::value_of_t()
ArgumentNotFound,
/// Represents an [I/O error].
/// Can occur when writing to `stderr` or `stdout` or reading a configuration file.
///
/// [I/O error]: std::io::Error
Io,
/// Represents a [Format error] (which is a part of [`Display`]).
/// Typically caused by writing to `stderr` or `stdout`.
///
/// [`Display`]: std::fmt::Display
/// [Format error]: std::fmt::Error
Format,
}
impl ErrorKind {
/// End-user description of the error case, where relevant
pub fn as_str(self) -> Option<&'static str> {
match self {
Self::InvalidValue => Some("One of the values isn't valid for an argument"),
Self::UnknownArgument => {
Some("Found an argument which wasn't expected or isn't valid in this context")
}
Self::InvalidSubcommand => Some("A subcommand wasn't recognized"),
Self::UnrecognizedSubcommand => Some("A subcommand wasn't recognized"),
Self::EmptyValue => Some("An argument requires a value but none was supplied"),
Self::NoEquals => Some("Equal is needed when assigning values to one of the arguments"),
Self::ValueValidation => Some("Invalid value for one of the arguments"),
Self::TooManyValues => Some("An argument received an unexpected value"),
Self::TooFewValues => Some("An argument requires more values"),
Self::TooManyOccurrences => Some("An argument occurred too many times"),
Self::WrongNumberOfValues => Some("An argument received too many or too few values"),
Self::ArgumentConflict => {
Some("An argument cannot be used with one or more of the other specified arguments")
}
Self::MissingRequiredArgument => {
Some("One or more required arguments were not provided")
}
Self::MissingSubcommand => Some("A subcommand is required but one was not provided"),
Self::UnexpectedMultipleUsage => {
Some("An argument was provided more than once but cannot be used multiple times")
}
Self::InvalidUtf8 => Some("Invalid UTF-8 was detected in one or more arguments"),
Self::DisplayHelp => None,
Self::DisplayHelpOnMissingArgumentOrSubcommand => None,
Self::DisplayVersion => None,
Self::ArgumentNotFound => Some("An argument wasn't found"),
Self::Io => None,
Self::Format => None,
}
}
}
impl std::fmt::Display for ErrorKind {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
self.as_str().unwrap_or_default().fmt(f)
}
}