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// Std
#[cfg(feature = "env")]
use std::env;
#[cfg(feature = "env")]
use std::ffi::OsString;
use std::{
cmp::{Ord, Ordering},
fmt::{self, Display, Formatter},
str,
};
// Internal
use super::{ArgFlags, ArgSettings};
#[cfg(feature = "unstable-ext")]
use crate::builder::ext::Extension;
use crate::builder::ext::Extensions;
use crate::builder::ArgPredicate;
use crate::builder::IntoResettable;
use crate::builder::OsStr;
use crate::builder::PossibleValue;
use crate::builder::Str;
use crate::builder::StyledStr;
use crate::builder::Styles;
use crate::builder::ValueRange;
use crate::util::AnyValueId;
use crate::ArgAction;
use crate::Id;
use crate::ValueHint;
use crate::INTERNAL_ERROR_MSG;
/// The abstract representation of a command line argument. Used to set all the options and
/// relationships that define a valid argument for the program.
///
/// There are two methods for constructing [`Arg`]s, using the builder pattern and setting options
/// manually, or using a usage string which is far less verbose but has fewer options. You can also
/// use a combination of the two methods to achieve the best of both worlds.
///
/// - [Basic API][crate::Arg#basic-api]
/// - [Value Handling][crate::Arg#value-handling]
/// - [Help][crate::Arg#help-1]
/// - [Advanced Argument Relations][crate::Arg#advanced-argument-relations]
/// - [Reflection][crate::Arg#reflection]
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Arg, arg, ArgAction};
/// // Using the traditional builder pattern and setting each option manually
/// let cfg = Arg::new("config")
/// .short('c')
/// .long("config")
/// .action(ArgAction::Set)
/// .value_name("FILE")
/// .help("Provides a config file to myprog");
/// // Using a usage string (setting a similar argument to the one above)
/// let input = arg!(-i --input <FILE> "Provides an input file to the program");
/// ```
#[derive(Default, Clone)]
pub struct Arg {
pub(crate) id: Id,
pub(crate) help: Option<StyledStr>,
pub(crate) long_help: Option<StyledStr>,
pub(crate) action: Option<ArgAction>,
pub(crate) value_parser: Option<super::ValueParser>,
pub(crate) blacklist: Vec<Id>,
pub(crate) settings: ArgFlags,
pub(crate) overrides: Vec<Id>,
pub(crate) groups: Vec<Id>,
pub(crate) requires: Vec<(ArgPredicate, Id)>,
pub(crate) r_ifs: Vec<(Id, OsStr)>,
pub(crate) r_ifs_all: Vec<(Id, OsStr)>,
pub(crate) r_unless: Vec<Id>,
pub(crate) r_unless_all: Vec<Id>,
pub(crate) short: Option<char>,
pub(crate) long: Option<Str>,
pub(crate) aliases: Vec<(Str, bool)>, // (name, visible)
pub(crate) short_aliases: Vec<(char, bool)>, // (name, visible)
pub(crate) disp_ord: Option<usize>,
pub(crate) val_names: Vec<Str>,
pub(crate) num_vals: Option<ValueRange>,
pub(crate) val_delim: Option<char>,
pub(crate) default_vals: Vec<OsStr>,
pub(crate) default_vals_ifs: Vec<(Id, ArgPredicate, Option<OsStr>)>,
pub(crate) default_missing_vals: Vec<OsStr>,
#[cfg(feature = "env")]
pub(crate) env: Option<(OsStr, Option<OsString>)>,
pub(crate) terminator: Option<Str>,
pub(crate) index: Option<usize>,
pub(crate) help_heading: Option<Option<Str>>,
pub(crate) ext: Extensions,
}
/// # Basic API
impl Arg {
/// Create a new [`Arg`] with a unique name.
///
/// The name is used to check whether or not the argument was used at
/// runtime, get values, set relationships with other args, etc..
///
/// **NOTE:** In the case of arguments that take values (i.e. [`Arg::action(ArgAction::Set)`])
/// and positional arguments (i.e. those without a preceding `-` or `--`) the name will also
/// be displayed when the user prints the usage/help information of the program.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// Arg::new("config")
/// # ;
/// ```
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
pub fn new(id: impl Into<Id>) -> Self {
Arg::default().id(id)
}
/// Set the identifier used for referencing this argument in the clap API.
///
/// See [`Arg::new`] for more details.
#[must_use]
pub fn id(mut self, id: impl Into<Id>) -> Self {
self.id = id.into();
self
}
/// Sets the short version of the argument without the preceding `-`.
///
/// By default `V` and `h` are used by the auto-generated `version` and `help` arguments,
/// respectively. You will need to disable the auto-generated flags
/// ([`disable_help_flag`][crate::Command::disable_help_flag],
/// [`disable_version_flag`][crate::Command::disable_version_flag]) and define your own.
///
/// # Examples
///
/// When calling `short`, use a single valid UTF-8 character which will allow using the
/// argument via a single hyphen (`-`) such as `-c`:
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("config")
/// .short('c')
/// .action(ArgAction::Set))
/// .get_matches_from(vec![
/// "prog", "-c", "file.toml"
/// ]);
///
/// assert_eq!(m.get_one::<String>("config").map(String::as_str), Some("file.toml"));
/// ```
///
/// To use `-h` for your own flag and still have help:
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .disable_help_flag(true)
/// .arg(Arg::new("host")
/// .short('h')
/// .long("host"))
/// .arg(Arg::new("help")
/// .long("help")
/// .global(true)
/// .action(ArgAction::Help))
/// .get_matches_from(vec![
/// "prog", "-h", "wikipedia.org"
/// ]);
///
/// assert_eq!(m.get_one::<String>("host").map(String::as_str), Some("wikipedia.org"));
/// ```
#[inline]
#[must_use]
pub fn short(mut self, s: impl IntoResettable<char>) -> Self {
if let Some(s) = s.into_resettable().into_option() {
debug_assert!(s != '-', "short option name cannot be `-`");
self.short = Some(s);
} else {
self.short = None;
}
self
}
/// Sets the long version of the argument without the preceding `--`.
///
/// By default `version` and `help` are used by the auto-generated `version` and `help`
/// arguments, respectively. You may use the word `version` or `help` for the long form of your
/// own arguments, in which case `clap` simply will not assign those to the auto-generated
/// `version` or `help` arguments.
///
/// **NOTE:** Any leading `-` characters will be stripped
///
/// # Examples
///
/// To set `long` use a word containing valid UTF-8. If you supply a double leading
/// `--` such as `--config` they will be stripped. Hyphens in the middle of the word, however,
/// will *not* be stripped (i.e. `config-file` is allowed).
///
/// Setting `long` allows using the argument via a double hyphen (`--`) such as `--config`
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .long("config")
/// .action(ArgAction::Set))
/// .get_matches_from(vec![
/// "prog", "--config", "file.toml"
/// ]);
///
/// assert_eq!(m.get_one::<String>("cfg").map(String::as_str), Some("file.toml"));
/// ```
#[inline]
#[must_use]
pub fn long(mut self, l: impl IntoResettable<Str>) -> Self {
self.long = l.into_resettable().into_option();
self
}
/// Add an alias, which functions as a hidden long flag.
///
/// This is more efficient, and easier than creating multiple hidden arguments as one only
/// needs to check for the existence of this command, and not all variants.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("test")
/// .long("test")
/// .alias("alias")
/// .action(ArgAction::Set))
/// .get_matches_from(vec![
/// "prog", "--alias", "cool"
/// ]);
/// assert_eq!(m.get_one::<String>("test").unwrap(), "cool");
/// ```
#[must_use]
pub fn alias(mut self, name: impl IntoResettable<Str>) -> Self {
if let Some(name) = name.into_resettable().into_option() {
self.aliases.push((name, false));
} else {
self.aliases.clear();
}
self
}
/// Add an alias, which functions as a hidden short flag.
///
/// This is more efficient, and easier than creating multiple hidden arguments as one only
/// needs to check for the existence of this command, and not all variants.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("test")
/// .short('t')
/// .short_alias('e')
/// .action(ArgAction::Set))
/// .get_matches_from(vec![
/// "prog", "-e", "cool"
/// ]);
/// assert_eq!(m.get_one::<String>("test").unwrap(), "cool");
/// ```
#[must_use]
pub fn short_alias(mut self, name: impl IntoResettable<char>) -> Self {
if let Some(name) = name.into_resettable().into_option() {
debug_assert!(name != '-', "short alias name cannot be `-`");
self.short_aliases.push((name, false));
} else {
self.short_aliases.clear();
}
self
}
/// Add aliases, which function as hidden long flags.
///
/// This is more efficient, and easier than creating multiple hidden subcommands as one only
/// needs to check for the existence of this command, and not all variants.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("test")
/// .long("test")
/// .aliases(["do-stuff", "do-tests", "tests"])
/// .action(ArgAction::SetTrue)
/// .help("the file to add")
/// .required(false))
/// .get_matches_from(vec![
/// "prog", "--do-tests"
/// ]);
/// assert_eq!(m.get_flag("test"), true);
/// ```
#[must_use]
pub fn aliases(mut self, names: impl IntoIterator<Item = impl Into<Str>>) -> Self {
self.aliases
.extend(names.into_iter().map(|x| (x.into(), false)));
self
}
/// Add aliases, which functions as a hidden short flag.
///
/// This is more efficient, and easier than creating multiple hidden subcommands as one only
/// needs to check for the existence of this command, and not all variants.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("test")
/// .short('t')
/// .short_aliases(['e', 's'])
/// .action(ArgAction::SetTrue)
/// .help("the file to add")
/// .required(false))
/// .get_matches_from(vec![
/// "prog", "-s"
/// ]);
/// assert_eq!(m.get_flag("test"), true);
/// ```
#[must_use]
pub fn short_aliases(mut self, names: impl IntoIterator<Item = char>) -> Self {
for s in names {
debug_assert!(s != '-', "short alias name cannot be `-`");
self.short_aliases.push((s, false));
}
self
}
/// Add an alias, which functions as a visible long flag.
///
/// Like [`Arg::alias`], except that they are visible inside the help message.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("test")
/// .visible_alias("something-awesome")
/// .long("test")
/// .action(ArgAction::Set))
/// .get_matches_from(vec![
/// "prog", "--something-awesome", "coffee"
/// ]);
/// assert_eq!(m.get_one::<String>("test").unwrap(), "coffee");
/// ```
/// [`Command::alias`]: Arg::alias()
#[must_use]
pub fn visible_alias(mut self, name: impl IntoResettable<Str>) -> Self {
if let Some(name) = name.into_resettable().into_option() {
self.aliases.push((name, true));
} else {
self.aliases.clear();
}
self
}
/// Add an alias, which functions as a visible short flag.
///
/// Like [`Arg::short_alias`], except that they are visible inside the help message.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("test")
/// .long("test")
/// .visible_short_alias('t')
/// .action(ArgAction::Set))
/// .get_matches_from(vec![
/// "prog", "-t", "coffee"
/// ]);
/// assert_eq!(m.get_one::<String>("test").unwrap(), "coffee");
/// ```
#[must_use]
pub fn visible_short_alias(mut self, name: impl IntoResettable<char>) -> Self {
if let Some(name) = name.into_resettable().into_option() {
debug_assert!(name != '-', "short alias name cannot be `-`");
self.short_aliases.push((name, true));
} else {
self.short_aliases.clear();
}
self
}
/// Add aliases, which function as visible long flags.
///
/// Like [`Arg::aliases`], except that they are visible inside the help message.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("test")
/// .long("test")
/// .action(ArgAction::SetTrue)
/// .visible_aliases(["something", "awesome", "cool"]))
/// .get_matches_from(vec![
/// "prog", "--awesome"
/// ]);
/// assert_eq!(m.get_flag("test"), true);
/// ```
/// [`Command::aliases`]: Arg::aliases()
#[must_use]
pub fn visible_aliases(mut self, names: impl IntoIterator<Item = impl Into<Str>>) -> Self {
self.aliases
.extend(names.into_iter().map(|n| (n.into(), true)));
self
}
/// Add aliases, which function as visible short flags.
///
/// Like [`Arg::short_aliases`], except that they are visible inside the help message.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("test")
/// .long("test")
/// .action(ArgAction::SetTrue)
/// .visible_short_aliases(['t', 'e']))
/// .get_matches_from(vec![
/// "prog", "-t"
/// ]);
/// assert_eq!(m.get_flag("test"), true);
/// ```
#[must_use]
pub fn visible_short_aliases(mut self, names: impl IntoIterator<Item = char>) -> Self {
for n in names {
debug_assert!(n != '-', "short alias name cannot be `-`");
self.short_aliases.push((n, true));
}
self
}
/// Specifies the index of a positional argument **starting at** 1.
///
/// **NOTE:** The index refers to position according to **other positional argument**. It does
/// not define position in the argument list as a whole.
///
/// **NOTE:** You can optionally leave off the `index` method, and the index will be
/// assigned in order of evaluation. Utilizing the `index` method allows for setting
/// indexes out of order
///
/// **NOTE:** This is only meant to be used for positional arguments and shouldn't to be used
/// with [`Arg::short`] or [`Arg::long`].
///
/// **NOTE:** When utilized with [`Arg::num_args(1..)`], only the **last** positional argument
/// may be defined as having a variable number of arguments (i.e. with the highest index)
///
/// # Panics
///
/// [`Command`] will [`panic!`] if indexes are skipped (such as defining `index(1)` and `index(3)`
/// but not `index(2)`, or a positional argument is defined as multiple and is not the highest
/// index (debug builds)
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// Arg::new("config")
/// .index(1)
/// # ;
/// ```
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("mode")
/// .index(1))
/// .arg(Arg::new("debug")
/// .long("debug")
/// .action(ArgAction::SetTrue))
/// .get_matches_from(vec![
/// "prog", "--debug", "fast"
/// ]);
///
/// assert!(m.contains_id("mode"));
/// assert_eq!(m.get_one::<String>("mode").unwrap(), "fast"); // notice index(1) means "first positional"
/// // *not* first argument
/// ```
/// [`Arg::short`]: Arg::short()
/// [`Arg::long`]: Arg::long()
/// [`Arg::num_args(true)`]: Arg::num_args()
/// [`Command`]: crate::Command
#[inline]
#[must_use]
pub fn index(mut self, idx: impl IntoResettable<usize>) -> Self {
self.index = idx.into_resettable().into_option();
self
}
/// This is a "var arg" and everything that follows should be captured by it, as if the user had
/// used a `--`.
///
/// **NOTE:** To start the trailing "var arg" on unknown flags (and not just a positional
/// value), set [`allow_hyphen_values`][Arg::allow_hyphen_values]. Either way, users still
/// have the option to explicitly escape ambiguous arguments with `--`.
///
/// **NOTE:** [`Arg::value_delimiter`] still applies if set.
///
/// **NOTE:** Setting this requires [`Arg::num_args(..)`].
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, arg};
/// let m = Command::new("myprog")
/// .arg(arg!(<cmd> ... "commands to run").trailing_var_arg(true))
/// .get_matches_from(vec!["myprog", "arg1", "-r", "val1"]);
///
/// let trail: Vec<_> = m.get_many::<String>("cmd").unwrap().collect();
/// assert_eq!(trail, ["arg1", "-r", "val1"]);
/// ```
/// [`Arg::num_args(..)`]: crate::Arg::num_args()
pub fn trailing_var_arg(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::TrailingVarArg)
} else {
self.unset_setting(ArgSettings::TrailingVarArg)
}
}
/// This arg is the last, or final, positional argument (i.e. has the highest
/// index) and is *only* able to be accessed via the `--` syntax (i.e. `$ prog args --
/// last_arg`).
///
/// Even, if no other arguments are left to parse, if the user omits the `--` syntax
/// they will receive an [`UnknownArgument`] error. Setting an argument to `.last(true)` also
/// allows one to access this arg early using the `--` syntax. Accessing an arg early, even with
/// the `--` syntax is otherwise not possible.
///
/// **NOTE:** This will change the usage string to look like `$ prog [OPTIONS] [-- <ARG>]` if
/// `ARG` is marked as `.last(true)`.
///
/// **NOTE:** This setting will imply [`crate::Command::dont_collapse_args_in_usage`] because failing
/// to set this can make the usage string very confusing.
///
/// **NOTE**: This setting only applies to positional arguments, and has no effect on OPTIONS
///
/// **NOTE:** Setting this requires [taking values][Arg::num_args]
///
/// **CAUTION:** Using this setting *and* having child subcommands is not
/// recommended with the exception of *also* using
/// [`crate::Command::args_conflicts_with_subcommands`]
/// (or [`crate::Command::subcommand_negates_reqs`] if the argument marked `Last` is also
/// marked [`Arg::required`])
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Arg, ArgAction};
/// Arg::new("args")
/// .action(ArgAction::Set)
/// .last(true)
/// # ;
/// ```
///
/// Setting `last` ensures the arg has the highest [index] of all positional args
/// and requires that the `--` syntax be used to access it early.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("first"))
/// .arg(Arg::new("second"))
/// .arg(Arg::new("third")
/// .action(ArgAction::Set)
/// .last(true))
/// .try_get_matches_from(vec![
/// "prog", "one", "--", "three"
/// ]);
///
/// assert!(res.is_ok());
/// let m = res.unwrap();
/// assert_eq!(m.get_one::<String>("third").unwrap(), "three");
/// assert_eq!(m.get_one::<String>("second"), None);
/// ```
///
/// Even if the positional argument marked `Last` is the only argument left to parse,
/// failing to use the `--` syntax results in an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("first"))
/// .arg(Arg::new("second"))
/// .arg(Arg::new("third")
/// .action(ArgAction::Set)
/// .last(true))
/// .try_get_matches_from(vec![
/// "prog", "one", "two", "three"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::UnknownArgument);
/// ```
/// [index]: Arg::index()
/// [`UnknownArgument`]: crate::error::ErrorKind::UnknownArgument
#[inline]
#[must_use]
pub fn last(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::Last)
} else {
self.unset_setting(ArgSettings::Last)
}
}
/// Specifies that the argument must be present.
///
/// Required by default means it is required, when no other conflicting rules or overrides have
/// been evaluated. Conflicting rules take precedence over being required.
///
/// **Pro tip:** Flags (i.e. not positional, or arguments that take values) shouldn't be
/// required by default. This is because if a flag were to be required, it should simply be
/// implied. No additional information is required from user. Flags by their very nature are
/// simply boolean on/off switches. The only time a user *should* be required to use a flag
/// is if the operation is destructive in nature, and the user is essentially proving to you,
/// "Yes, I know what I'm doing."
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .required(true)
/// # ;
/// ```
///
/// Setting required requires that the argument be used at runtime.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required(true)
/// .action(ArgAction::Set)
/// .long("config"))
/// .try_get_matches_from(vec![
/// "prog", "--config", "file.conf",
/// ]);
///
/// assert!(res.is_ok());
/// ```
///
/// Setting required and then *not* supplying that argument at runtime is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required(true)
/// .action(ArgAction::Set)
/// .long("config"))
/// .try_get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
#[inline]
#[must_use]
pub fn required(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::Required)
} else {
self.unset_setting(ArgSettings::Required)
}
}
/// Sets an argument that is required when this one is present
///
/// i.e. when using this argument, the following argument *must* be present.
///
/// **NOTE:** [Conflicting] rules and [override] rules take precedence over being required
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .requires("input")
/// # ;
/// ```
///
/// Setting [`Arg::requires(name)`] requires that the argument be used at runtime if the
/// defining argument is used. If the defining argument isn't used, the other argument isn't
/// required
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .requires("input")
/// .long("config"))
/// .arg(Arg::new("input"))
/// .try_get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert!(res.is_ok()); // We didn't use cfg, so input wasn't required
/// ```
///
/// Setting [`Arg::requires(name)`] and *not* supplying that argument is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .requires("input")
/// .long("config"))
/// .arg(Arg::new("input"))
/// .try_get_matches_from(vec![
/// "prog", "--config", "file.conf"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
/// [`Arg::requires(name)`]: Arg::requires()
/// [Conflicting]: Arg::conflicts_with()
/// [override]: Arg::overrides_with()
#[must_use]
pub fn requires(mut self, arg_id: impl IntoResettable<Id>) -> Self {
if let Some(arg_id) = arg_id.into_resettable().into_option() {
self.requires.push((ArgPredicate::IsPresent, arg_id));
} else {
self.requires.clear();
}
self
}
/// This argument must be passed alone; it conflicts with all other arguments.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .exclusive(true)
/// # ;
/// ```
///
/// Setting an exclusive argument and having any other arguments present at runtime
/// is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("exclusive")
/// .action(ArgAction::Set)
/// .exclusive(true)
/// .long("exclusive"))
/// .arg(Arg::new("debug")
/// .long("debug"))
/// .arg(Arg::new("input"))
/// .try_get_matches_from(vec![
/// "prog", "--exclusive", "file.conf", "file.txt"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::ArgumentConflict);
/// ```
#[inline]
#[must_use]
pub fn exclusive(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::Exclusive)
} else {
self.unset_setting(ArgSettings::Exclusive)
}
}
/// Specifies that an argument can be matched to all child [`Subcommand`]s.
///
/// **NOTE:** Global arguments *only* propagate down, **not** up (to parent commands), however
/// their values once a user uses them will be propagated back up to parents. In effect, this
/// means one should *define* all global arguments at the top level, however it doesn't matter
/// where the user *uses* the global argument.
///
/// # Examples
///
/// Assume an application with two subcommands, and you'd like to define a
/// `--verbose` flag that can be called on any of the subcommands and parent, but you don't
/// want to clutter the source with three duplicate [`Arg`] definitions.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("verb")
/// .long("verbose")
/// .short('v')
/// .action(ArgAction::SetTrue)
/// .global(true))
/// .subcommand(Command::new("test"))
/// .subcommand(Command::new("do-stuff"))
/// .get_matches_from(vec![
/// "prog", "do-stuff", "--verbose"
/// ]);
///
/// assert_eq!(m.subcommand_name(), Some("do-stuff"));
/// let sub_m = m.subcommand_matches("do-stuff").unwrap();
/// assert_eq!(sub_m.get_flag("verb"), true);
/// ```
///
/// [`Subcommand`]: crate::Subcommand
#[inline]
#[must_use]
pub fn global(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::Global)
} else {
self.unset_setting(ArgSettings::Global)
}
}
#[inline]
pub(crate) fn is_set(&self, s: ArgSettings) -> bool {
self.settings.is_set(s)
}
#[inline]
#[must_use]
pub(crate) fn setting(mut self, setting: ArgSettings) -> Self {
self.settings.set(setting);
self
}
#[inline]
#[must_use]
pub(crate) fn unset_setting(mut self, setting: ArgSettings) -> Self {
self.settings.unset(setting);
self
}
/// Extend [`Arg`] with [`ArgExt`] data
#[cfg(feature = "unstable-ext")]
#[allow(clippy::should_implement_trait)]
pub fn add<T: ArgExt + Extension>(mut self, tagged: T) -> Self {
self.ext.set(tagged);
self
}
}
/// # Value Handling
impl Arg {
/// Specify how to react to an argument when parsing it.
///
/// [`ArgAction`] controls things like
/// - Overwriting previous values with new ones
/// - Appending new values to all previous ones
/// - Counting how many times a flag occurs
///
/// The default action is `ArgAction::Set`
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Command;
/// # use clap::Arg;
/// let cmd = Command::new("mycmd")
/// .arg(
/// Arg::new("flag")
/// .long("flag")
/// .action(clap::ArgAction::Append)
/// );
///
/// let matches = cmd.try_get_matches_from(["mycmd", "--flag", "value"]).unwrap();
/// assert!(matches.contains_id("flag"));
/// assert_eq!(
/// matches.get_many::<String>("flag").unwrap_or_default().map(|v| v.as_str()).collect::<Vec<_>>(),
/// vec!["value"]
/// );
/// ```
#[inline]
#[must_use]
pub fn action(mut self, action: impl IntoResettable<ArgAction>) -> Self {
self.action = action.into_resettable().into_option();
self
}
/// Specify the typed behavior of the argument.
///
/// This allows parsing and validating a value before storing it into
/// [`ArgMatches`][crate::ArgMatches] as the given type.
///
/// Possible value parsers include:
/// - [`value_parser!(T)`][crate::value_parser!] for auto-selecting a value parser for a given type
/// - Or [range expressions like `0..=1`][std::ops::RangeBounds] as a shorthand for [`RangedI64ValueParser`][crate::builder::RangedI64ValueParser]
/// - `Fn(&str) -> Result<T, E>`
/// - `[&str]` and [`PossibleValuesParser`][crate::builder::PossibleValuesParser] for static enumerated values
/// - [`BoolishValueParser`][crate::builder::BoolishValueParser], and [`FalseyValueParser`][crate::builder::FalseyValueParser] for alternative `bool` implementations
/// - [`NonEmptyStringValueParser`][crate::builder::NonEmptyStringValueParser] for basic validation for strings
/// - or any other [`TypedValueParser`][crate::builder::TypedValueParser] implementation
///
/// The default value is [`ValueParser::string`][crate::builder::ValueParser::string].
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::ArgAction;
/// let mut cmd = clap::Command::new("raw")
/// .arg(
/// clap::Arg::new("color")
/// .long("color")
/// .value_parser(["always", "auto", "never"])
/// .default_value("auto")
/// )
/// .arg(
/// clap::Arg::new("hostname")
/// .long("hostname")
/// .value_parser(clap::builder::NonEmptyStringValueParser::new())
/// .action(ArgAction::Set)
/// .required(true)
/// )
/// .arg(
/// clap::Arg::new("port")
/// .long("port")
/// .value_parser(clap::value_parser!(u16).range(3000..))
/// .action(ArgAction::Set)
/// .required(true)
/// );
///
/// let m = cmd.try_get_matches_from_mut(
/// ["cmd", "--hostname", "rust-lang.org", "--port", "3001"]
/// ).unwrap();
///
/// let color: &String = m.get_one("color")
/// .expect("default");
/// assert_eq!(color, "auto");
///
/// let hostname: &String = m.get_one("hostname")
/// .expect("required");
/// assert_eq!(hostname, "rust-lang.org");
///
/// let port: u16 = *m.get_one("port")
/// .expect("required");
/// assert_eq!(port, 3001);
/// ```
pub fn value_parser(mut self, parser: impl IntoResettable<super::ValueParser>) -> Self {
self.value_parser = parser.into_resettable().into_option();
self
}
/// Specifies the number of arguments parsed per occurrence
///
/// For example, if you had a `-f <file>` argument where you wanted exactly 3 'files' you would
/// set `.num_args(3)`, and this argument wouldn't be satisfied unless the user
/// provided 3 and only 3 values.
///
/// Users may specify values for arguments in any of the following methods
///
/// - Using a space such as `-o value` or `--option value`
/// - Using an equals and no space such as `-o=value` or `--option=value`
/// - Use a short and no space such as `-ovalue`
///
/// **WARNING:**
///
/// Setting a variable number of values (e.g. `1..=10`) for an argument without
/// other details can be dangerous in some circumstances. Because multiple values are
/// allowed, `--option val1 val2 val3` is perfectly valid. Be careful when designing a CLI
/// where **positional arguments** or **subcommands** are *also* expected as `clap` will continue
/// parsing *values* until one of the following happens:
///
/// - It reaches the maximum number of values
/// - It reaches a specific number of values
/// - It finds another flag or option (i.e. something that starts with a `-`)
/// - It reaches the [`Arg::value_terminator`] if set
///
/// Alternatively,
/// - Use a delimiter between values with [`Arg::value_delimiter`]
/// - Require a flag occurrence per value with [`ArgAction::Append`]
/// - Require positional arguments to appear after `--` with [`Arg::last`]
///
/// # Examples
///
/// Option:
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("mode")
/// .long("mode")
/// .num_args(1))
/// .get_matches_from(vec![
/// "prog", "--mode", "fast"
/// ]);
///
/// assert_eq!(m.get_one::<String>("mode").unwrap(), "fast");
/// ```
///
/// Flag/option hybrid (see also [`default_missing_value`][Arg::default_missing_value])
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let cmd = Command::new("prog")
/// .arg(Arg::new("mode")
/// .long("mode")
/// .default_missing_value("slow")
/// .default_value("plaid")
/// .num_args(0..=1));
///
/// let m = cmd.clone()
/// .get_matches_from(vec![
/// "prog", "--mode", "fast"
/// ]);
/// assert_eq!(m.get_one::<String>("mode").unwrap(), "fast");
///
/// let m = cmd.clone()
/// .get_matches_from(vec![
/// "prog", "--mode",
/// ]);
/// assert_eq!(m.get_one::<String>("mode").unwrap(), "slow");
///
/// let m = cmd.clone()
/// .get_matches_from(vec![
/// "prog",
/// ]);
/// assert_eq!(m.get_one::<String>("mode").unwrap(), "plaid");
/// ```
///
/// Tuples
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let cmd = Command::new("prog")
/// .arg(Arg::new("file")
/// .action(ArgAction::Set)
/// .num_args(2)
/// .short('F'));
///
/// let m = cmd.clone()
/// .get_matches_from(vec![
/// "prog", "-F", "in-file", "out-file"
/// ]);
/// assert_eq!(
/// m.get_many::<String>("file").unwrap_or_default().map(|v| v.as_str()).collect::<Vec<_>>(),
/// vec!["in-file", "out-file"]
/// );
///
/// let res = cmd.clone()
/// .try_get_matches_from(vec![
/// "prog", "-F", "file1"
/// ]);
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::WrongNumberOfValues);
/// ```
///
/// A common mistake is to define an option which allows multiple values and a positional
/// argument.
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let cmd = Command::new("prog")
/// .arg(Arg::new("file")
/// .action(ArgAction::Set)
/// .num_args(0..)
/// .short('F'))
/// .arg(Arg::new("word"));
///
/// let m = cmd.clone().get_matches_from(vec![
/// "prog", "-F", "file1", "file2", "file3", "word"
/// ]);
/// let files: Vec<_> = m.get_many::<String>("file").unwrap().collect();
/// assert_eq!(files, ["file1", "file2", "file3", "word"]); // wait...what?!
/// assert!(!m.contains_id("word")); // but we clearly used word!
///
/// // but this works
/// let m = cmd.clone().get_matches_from(vec![
/// "prog", "word", "-F", "file1", "file2", "file3",
/// ]);
/// let files: Vec<_> = m.get_many::<String>("file").unwrap().collect();
/// assert_eq!(files, ["file1", "file2", "file3"]);
/// assert_eq!(m.get_one::<String>("word").unwrap(), "word");
/// ```
/// The problem is `clap` doesn't know when to stop parsing values for "file".
///
/// A solution for the example above is to limit how many values with a maximum, or specific
/// number, or to say [`ArgAction::Append`] is ok, but multiple values are not.
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("file")
/// .action(ArgAction::Append)
/// .short('F'))
/// .arg(Arg::new("word"))
/// .get_matches_from(vec![
/// "prog", "-F", "file1", "-F", "file2", "-F", "file3", "word"
/// ]);
///
/// let files: Vec<_> = m.get_many::<String>("file").unwrap().collect();
/// assert_eq!(files, ["file1", "file2", "file3"]);
/// assert_eq!(m.get_one::<String>("word").unwrap(), "word");
/// ```
#[inline]
#[must_use]
pub fn num_args(mut self, qty: impl IntoResettable<ValueRange>) -> Self {
self.num_vals = qty.into_resettable().into_option();
self
}
#[doc(hidden)]
#[cfg_attr(
feature = "deprecated",
deprecated(since = "4.0.0", note = "Replaced with `Arg::num_args`")
)]
pub fn number_of_values(self, qty: usize) -> Self {
self.num_args(qty)
}
/// Placeholder for the argument's value in the help message / usage.
///
/// This name is cosmetic only; the name is **not** used to access arguments.
/// This setting can be very helpful when describing the type of input the user should be
/// using, such as `FILE`, `INTERFACE`, etc. Although not required, it's somewhat convention to
/// use all capital letters for the value name.
///
/// **NOTE:** implicitly sets [`Arg::action(ArgAction::Set)`]
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// Arg::new("cfg")
/// .long("config")
/// .value_name("FILE")
/// # ;
/// ```
///
/// ```rust
/// # use clap_builder as clap;
/// # #[cfg(feature = "help")] {
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("config")
/// .long("config")
/// .value_name("FILE")
/// .help("Some help text"))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
/// # }
/// ```
/// Running the above program produces the following output
///
/// ```text
/// valnames
///
/// Usage: valnames [OPTIONS]
///
/// Options:
/// --config <FILE> Some help text
/// -h, --help Print help information
/// -V, --version Print version information
/// ```
/// [positional]: Arg::index()
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
#[inline]
#[must_use]
pub fn value_name(mut self, name: impl IntoResettable<Str>) -> Self {
if let Some(name) = name.into_resettable().into_option() {
self.value_names([name])
} else {
self.val_names.clear();
self
}
}
/// Placeholders for the argument's values in the help message / usage.
///
/// These names are cosmetic only, used for help and usage strings only. The names are **not**
/// used to access arguments. The values of the arguments are accessed in numeric order (i.e.
/// if you specify two names `one` and `two` `one` will be the first matched value, `two` will
/// be the second).
///
/// This setting can be very helpful when describing the type of input the user should be
/// using, such as `FILE`, `INTERFACE`, etc. Although not required, it's somewhat convention to
/// use all capital letters for the value name.
///
/// **Pro Tip:** It may help to use [`Arg::next_line_help(true)`] if there are long, or
/// multiple value names in order to not throw off the help text alignment of all options.
///
/// **NOTE:** implicitly sets [`Arg::action(ArgAction::Set)`] and [`Arg::num_args(1..)`].
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// Arg::new("speed")
/// .short('s')
/// .value_names(["fast", "slow"]);
/// ```
///
/// ```rust
/// # use clap_builder as clap;
/// # #[cfg(feature = "help")] {
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("io")
/// .long("io-files")
/// .value_names(["INFILE", "OUTFILE"]))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
/// # }
/// ```
///
/// Running the above program produces the following output
///
/// ```text
/// valnames
///
/// Usage: valnames [OPTIONS]
///
/// Options:
/// -h, --help Print help information
/// --io-files <INFILE> <OUTFILE> Some help text
/// -V, --version Print version information
/// ```
/// [`Arg::next_line_help(true)`]: Arg::next_line_help()
/// [`Arg::num_args`]: Arg::num_args()
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
/// [`Arg::num_args(1..)`]: Arg::num_args()
#[must_use]
pub fn value_names(mut self, names: impl IntoIterator<Item = impl Into<Str>>) -> Self {
self.val_names = names.into_iter().map(|s| s.into()).collect();
self
}
/// Provide the shell a hint about how to complete this argument.
///
/// See [`ValueHint`] for more information.
///
/// **NOTE:** implicitly sets [`Arg::action(ArgAction::Set)`].
///
/// For example, to take a username as argument:
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Arg, ValueHint};
/// Arg::new("user")
/// .short('u')
/// .long("user")
/// .value_hint(ValueHint::Username);
/// ```
///
/// To take a full command line and its arguments (for example, when writing a command wrapper):
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ValueHint, ArgAction};
/// Command::new("prog")
/// .trailing_var_arg(true)
/// .arg(
/// Arg::new("command")
/// .action(ArgAction::Set)
/// .num_args(1..)
/// .value_hint(ValueHint::CommandWithArguments)
/// );
/// ```
#[must_use]
pub fn value_hint(mut self, value_hint: impl IntoResettable<ValueHint>) -> Self {
// HACK: we should use `Self::add` and `Self::remove` to type-check that `ArgExt` is used
match value_hint.into_resettable().into_option() {
Some(value_hint) => {
self.ext.set(value_hint);
}
None => {
self.ext.remove::<ValueHint>();
}
}
self
}
/// Match values against [`PossibleValuesParser`][crate::builder::PossibleValuesParser] without matching case.
///
/// When other arguments are conditionally required based on the
/// value of a case-insensitive argument, the equality check done
/// by [`Arg::required_if_eq`], [`Arg::required_if_eq_any`], or
/// [`Arg::required_if_eq_all`] is case-insensitive.
///
///
/// **NOTE:** Setting this requires [taking values][Arg::num_args]
///
/// **NOTE:** To do unicode case folding, enable the `unicode` feature flag.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("pv")
/// .arg(Arg::new("option")
/// .long("option")
/// .action(ArgAction::Set)
/// .ignore_case(true)
/// .value_parser(["test123"]))
/// .get_matches_from(vec![
/// "pv", "--option", "TeSt123",
/// ]);
///
/// assert!(m.get_one::<String>("option").unwrap().eq_ignore_ascii_case("test123"));
/// ```
///
/// This setting also works when multiple values can be defined:
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("pv")
/// .arg(Arg::new("option")
/// .short('o')
/// .long("option")
/// .action(ArgAction::Set)
/// .ignore_case(true)
/// .num_args(1..)
/// .value_parser(["test123", "test321"]))
/// .get_matches_from(vec![
/// "pv", "--option", "TeSt123", "teST123", "tESt321"
/// ]);
///
/// let matched_vals = m.get_many::<String>("option").unwrap().collect::<Vec<_>>();
/// assert_eq!(&*matched_vals, &["TeSt123", "teST123", "tESt321"]);
/// ```
#[inline]
#[must_use]
pub fn ignore_case(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::IgnoreCase)
} else {
self.unset_setting(ArgSettings::IgnoreCase)
}
}
/// Allows values which start with a leading hyphen (`-`)
///
/// To limit values to just numbers, see
/// [`allow_negative_numbers`][Arg::allow_negative_numbers].
///
/// See also [`trailing_var_arg`][Arg::trailing_var_arg].
///
/// **NOTE:** Setting this requires [taking values][Arg::num_args]
///
/// **WARNING:** Prior arguments with `allow_hyphen_values(true)` get precedence over known
/// flags but known flags get precedence over the next possible positional argument with
/// `allow_hyphen_values(true)`. When combined with [`Arg::num_args(..)`],
/// [`Arg::value_terminator`] is one way to ensure processing stops.
///
/// **WARNING**: Take caution when using this setting combined with another argument using
/// [`Arg::num_args`], as this becomes ambiguous `$ prog --arg -- -- val`. All
/// three `--, --, val` will be values when the user may have thought the second `--` would
/// constitute the normal, "Only positional args follow" idiom.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("pat")
/// .action(ArgAction::Set)
/// .allow_hyphen_values(true)
/// .long("pattern"))
/// .get_matches_from(vec![
/// "prog", "--pattern", "-file"
/// ]);
///
/// assert_eq!(m.get_one::<String>("pat").unwrap(), "-file");
/// ```
///
/// Not setting `Arg::allow_hyphen_values(true)` and supplying a value which starts with a
/// hyphen is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("pat")
/// .action(ArgAction::Set)
/// .long("pattern"))
/// .try_get_matches_from(vec![
/// "prog", "--pattern", "-file"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::UnknownArgument);
/// ```
/// [`Arg::num_args(1)`]: Arg::num_args()
#[inline]
#[must_use]
pub fn allow_hyphen_values(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::AllowHyphenValues)
} else {
self.unset_setting(ArgSettings::AllowHyphenValues)
}
}
/// Allows negative numbers to pass as values.
///
/// This is similar to [`Arg::allow_hyphen_values`] except that it only allows numbers,
/// all other undefined leading hyphens will fail to parse.
///
/// **NOTE:** Setting this requires [taking values][Arg::num_args]
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let res = Command::new("myprog")
/// .arg(Arg::new("num").allow_negative_numbers(true))
/// .try_get_matches_from(vec![
/// "myprog", "-20"
/// ]);
/// assert!(res.is_ok());
/// let m = res.unwrap();
/// assert_eq!(m.get_one::<String>("num").unwrap(), "-20");
/// ```
#[inline]
pub fn allow_negative_numbers(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::AllowNegativeNumbers)
} else {
self.unset_setting(ArgSettings::AllowNegativeNumbers)
}
}
/// Requires that options use the `--option=val` syntax
///
/// i.e. an equals between the option and associated value.
///
/// **NOTE:** Setting this requires [taking values][Arg::num_args]
///
/// # Examples
///
/// Setting `require_equals` requires that the option have an equals sign between
/// it and the associated value.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .require_equals(true)
/// .long("config"))
/// .try_get_matches_from(vec![
/// "prog", "--config=file.conf"
/// ]);
///
/// assert!(res.is_ok());
/// ```
///
/// Setting `require_equals` and *not* supplying the equals will cause an
/// error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .require_equals(true)
/// .long("config"))
/// .try_get_matches_from(vec![
/// "prog", "--config", "file.conf"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::NoEquals);
/// ```
#[inline]
#[must_use]
pub fn require_equals(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::RequireEquals)
} else {
self.unset_setting(ArgSettings::RequireEquals)
}
}
#[doc(hidden)]
#[cfg_attr(
feature = "deprecated",
deprecated(since = "4.0.0", note = "Replaced with `Arg::value_delimiter`")
)]
pub fn use_value_delimiter(mut self, yes: bool) -> Self {
if yes {
self.val_delim.get_or_insert(',');
} else {
self.val_delim = None;
}
self
}
/// Allow grouping of multiple values via a delimiter.
///
/// i.e. allow values (`val1,val2,val3`) to be parsed as three values (`val1`, `val2`,
/// and `val3`) instead of one value (`val1,val2,val3`).
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("config")
/// .short('c')
/// .long("config")
/// .value_delimiter(','))
/// .get_matches_from(vec![
/// "prog", "--config=val1,val2,val3"
/// ]);
///
/// assert_eq!(m.get_many::<String>("config").unwrap().collect::<Vec<_>>(), ["val1", "val2", "val3"])
/// ```
/// [`Arg::value_delimiter(',')`]: Arg::value_delimiter()
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
#[inline]
#[must_use]
pub fn value_delimiter(mut self, d: impl IntoResettable<char>) -> Self {
self.val_delim = d.into_resettable().into_option();
self
}
/// Sentinel to **stop** parsing multiple values of a given argument.
///
/// By default when
/// one sets [`num_args(1..)`] on an argument, clap will continue parsing values for that
/// argument until it reaches another valid argument, or one of the other more specific settings
/// for multiple values is used (such as [`num_args`]).
///
/// **NOTE:** This setting only applies to [options] and [positional arguments]
///
/// **NOTE:** When the terminator is passed in on the command line, it is **not** stored as one
/// of the values
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// Arg::new("vals")
/// .action(ArgAction::Set)
/// .num_args(1..)
/// .value_terminator(";")
/// # ;
/// ```
///
/// The following example uses two arguments, a sequence of commands, and the location in which
/// to perform them
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("cmds")
/// .action(ArgAction::Set)
/// .num_args(1..)
/// .allow_hyphen_values(true)
/// .value_terminator(";"))
/// .arg(Arg::new("location"))
/// .get_matches_from(vec![
/// "prog", "find", "-type", "f", "-name", "special", ";", "/home/clap"
/// ]);
/// let cmds: Vec<_> = m.get_many::<String>("cmds").unwrap().collect();
/// assert_eq!(&cmds, &["find", "-type", "f", "-name", "special"]);
/// assert_eq!(m.get_one::<String>("location").unwrap(), "/home/clap");
/// ```
/// [options]: Arg::action
/// [positional arguments]: Arg::index()
/// [`num_args(1..)`]: Arg::num_args()
/// [`num_args`]: Arg::num_args()
#[inline]
#[must_use]
pub fn value_terminator(mut self, term: impl IntoResettable<Str>) -> Self {
self.terminator = term.into_resettable().into_option();
self
}
/// Consume all following arguments.
///
/// Do not be parse them individually, but rather pass them in entirety.
///
/// It is worth noting that setting this requires all values to come after a `--` to indicate
/// they should all be captured. For example:
///
/// ```text
/// --foo something -- -v -v -v -b -b -b --baz -q -u -x
/// ```
///
/// Will result in everything after `--` to be considered one raw argument. This behavior
/// may not be exactly what you are expecting and using [`Arg::trailing_var_arg`]
/// may be more appropriate.
///
/// **NOTE:** Implicitly sets [`Arg::action(ArgAction::Set)`] [`Arg::num_args(1..)`],
/// [`Arg::allow_hyphen_values(true)`], and [`Arg::last(true)`] when set to `true`.
///
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
/// [`Arg::num_args(1..)`]: Arg::num_args()
/// [`Arg::allow_hyphen_values(true)`]: Arg::allow_hyphen_values()
/// [`Arg::last(true)`]: Arg::last()
#[inline]
#[must_use]
pub fn raw(mut self, yes: bool) -> Self {
if yes {
self.num_vals.get_or_insert_with(|| (1..).into());
}
self.allow_hyphen_values(yes).last(yes)
}
/// Value for the argument when not present.
///
/// **NOTE:** If the user *does not* use this argument at runtime [`ArgMatches::contains_id`] will
/// still return `true`. If you wish to determine whether the argument was used at runtime or
/// not, consider [`ArgMatches::value_source`][crate::ArgMatches::value_source].
///
/// **NOTE:** This setting is perfectly compatible with [`Arg::default_value_if`] but slightly
/// different. `Arg::default_value` *only* takes effect when the user has not provided this arg
/// at runtime. `Arg::default_value_if` however only takes effect when the user has not provided
/// a value at runtime **and** these other conditions are met as well. If you have set
/// `Arg::default_value` and `Arg::default_value_if`, and the user **did not** provide this arg
/// at runtime, nor were the conditions met for `Arg::default_value_if`, the `Arg::default_value`
/// will be applied.
///
/// Like with command-line values, this will be split by [`Arg::value_delimiter`].
///
/// # Examples
///
/// First we use the default value without providing any value at runtime.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, parser::ValueSource};
/// let m = Command::new("prog")
/// .arg(Arg::new("opt")
/// .long("myopt")
/// .default_value("myval"))
/// .get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert_eq!(m.get_one::<String>("opt").unwrap(), "myval");
/// assert!(m.contains_id("opt"));
/// assert_eq!(m.value_source("opt"), Some(ValueSource::DefaultValue));
/// ```
///
/// Next we provide a value at runtime to override the default.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, parser::ValueSource};
/// let m = Command::new("prog")
/// .arg(Arg::new("opt")
/// .long("myopt")
/// .default_value("myval"))
/// .get_matches_from(vec![
/// "prog", "--myopt=non_default"
/// ]);
///
/// assert_eq!(m.get_one::<String>("opt").unwrap(), "non_default");
/// assert!(m.contains_id("opt"));
/// assert_eq!(m.value_source("opt"), Some(ValueSource::CommandLine));
/// ```
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
/// [`ArgMatches::contains_id`]: crate::ArgMatches::contains_id()
/// [`Arg::default_value_if`]: Arg::default_value_if()
#[inline]
#[must_use]
pub fn default_value(mut self, val: impl IntoResettable<OsStr>) -> Self {
if let Some(val) = val.into_resettable().into_option() {
self.default_values([val])
} else {
self.default_vals.clear();
self
}
}
#[inline]
#[must_use]
#[doc(hidden)]
#[cfg_attr(
feature = "deprecated",
deprecated(since = "4.0.0", note = "Replaced with `Arg::default_value`")
)]
pub fn default_value_os(self, val: impl Into<OsStr>) -> Self {
self.default_values([val])
}
/// Value for the argument when not present.
///
/// See [`Arg::default_value`].
///
/// [`Arg::default_value`]: Arg::default_value()
#[inline]
#[must_use]
pub fn default_values(mut self, vals: impl IntoIterator<Item = impl Into<OsStr>>) -> Self {
self.default_vals = vals.into_iter().map(|s| s.into()).collect();
self
}
#[inline]
#[must_use]
#[doc(hidden)]
#[cfg_attr(
feature = "deprecated",
deprecated(since = "4.0.0", note = "Replaced with `Arg::default_values`")
)]
pub fn default_values_os(self, vals: impl IntoIterator<Item = impl Into<OsStr>>) -> Self {
self.default_values(vals)
}
/// Value for the argument when the flag is present but no value is specified.
///
/// This configuration option is often used to give the user a shortcut and allow them to
/// efficiently specify an option argument without requiring an explicitly value. The `--color`
/// argument is a common example. By supplying a default, such as `default_missing_value("always")`,
/// the user can quickly just add `--color` to the command line to produce the desired color output.
///
/// **NOTE:** using this configuration option requires the use of the
/// [`.num_args(0..N)`][Arg::num_args] and the
/// [`.require_equals(true)`][Arg::require_equals] configuration option. These are required in
/// order to unambiguously determine what, if any, value was supplied for the argument.
///
/// Like with command-line values, this will be split by [`Arg::value_delimiter`].
///
/// # Examples
///
/// For POSIX style `--color`:
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, parser::ValueSource};
/// fn cli() -> Command {
/// Command::new("prog")
/// .arg(Arg::new("color").long("color")
/// .value_name("WHEN")
/// .value_parser(["always", "auto", "never"])
/// .default_value("auto")
/// .num_args(0..=1)
/// .require_equals(true)
/// .default_missing_value("always")
/// .help("Specify WHEN to colorize output.")
/// )
/// }
///
/// // first, we'll provide no arguments
/// let m = cli().get_matches_from(vec![
/// "prog"
/// ]);
/// assert_eq!(m.get_one::<String>("color").unwrap(), "auto");
/// assert_eq!(m.value_source("color"), Some(ValueSource::DefaultValue));
///
/// // next, we'll provide a runtime value to override the default (as usually done).
/// let m = cli().get_matches_from(vec![
/// "prog", "--color=never"
/// ]);
/// assert_eq!(m.get_one::<String>("color").unwrap(), "never");
/// assert_eq!(m.value_source("color"), Some(ValueSource::CommandLine));
///
/// // finally, we will use the shortcut and only provide the argument without a value.
/// let m = cli().get_matches_from(vec![
/// "prog", "--color"
/// ]);
/// assert_eq!(m.get_one::<String>("color").unwrap(), "always");
/// assert_eq!(m.value_source("color"), Some(ValueSource::CommandLine));
/// ```
///
/// For bool literals:
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, parser::ValueSource, value_parser};
/// fn cli() -> Command {
/// Command::new("prog")
/// .arg(Arg::new("create").long("create")
/// .value_name("BOOL")
/// .value_parser(value_parser!(bool))
/// .num_args(0..=1)
/// .require_equals(true)
/// .default_missing_value("true")
/// )
/// }
///
/// // first, we'll provide no arguments
/// let m = cli().get_matches_from(vec![
/// "prog"
/// ]);
/// assert_eq!(m.get_one::<bool>("create").copied(), None);
///
/// // next, we'll provide a runtime value to override the default (as usually done).
/// let m = cli().get_matches_from(vec![
/// "prog", "--create=false"
/// ]);
/// assert_eq!(m.get_one::<bool>("create").copied(), Some(false));
/// assert_eq!(m.value_source("create"), Some(ValueSource::CommandLine));
///
/// // finally, we will use the shortcut and only provide the argument without a value.
/// let m = cli().get_matches_from(vec![
/// "prog", "--create"
/// ]);
/// assert_eq!(m.get_one::<bool>("create").copied(), Some(true));
/// assert_eq!(m.value_source("create"), Some(ValueSource::CommandLine));
/// ```
///
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
/// [`Arg::default_value`]: Arg::default_value()
#[inline]
#[must_use]
pub fn default_missing_value(mut self, val: impl IntoResettable<OsStr>) -> Self {
if let Some(val) = val.into_resettable().into_option() {
self.default_missing_values_os([val])
} else {
self.default_missing_vals.clear();
self
}
}
/// Value for the argument when the flag is present but no value is specified.
///
/// See [`Arg::default_missing_value`].
///
/// [`Arg::default_missing_value`]: Arg::default_missing_value()
/// [`OsStr`]: std::ffi::OsStr
#[inline]
#[must_use]
pub fn default_missing_value_os(self, val: impl Into<OsStr>) -> Self {
self.default_missing_values_os([val])
}
/// Value for the argument when the flag is present but no value is specified.
///
/// See [`Arg::default_missing_value`].
///
/// [`Arg::default_missing_value`]: Arg::default_missing_value()
#[inline]
#[must_use]
pub fn default_missing_values(self, vals: impl IntoIterator<Item = impl Into<OsStr>>) -> Self {
self.default_missing_values_os(vals)
}
/// Value for the argument when the flag is present but no value is specified.
///
/// See [`Arg::default_missing_values`].
///
/// [`Arg::default_missing_values`]: Arg::default_missing_values()
/// [`OsStr`]: std::ffi::OsStr
#[inline]
#[must_use]
pub fn default_missing_values_os(
mut self,
vals: impl IntoIterator<Item = impl Into<OsStr>>,
) -> Self {
self.default_missing_vals = vals.into_iter().map(|s| s.into()).collect();
self
}
/// Read from `name` environment variable when argument is not present.
///
/// If it is not present in the environment, then default
/// rules will apply.
///
/// If user sets the argument in the environment:
/// - When [`Arg::action(ArgAction::Set)`] is not set, the flag is considered raised.
/// - When [`Arg::action(ArgAction::Set)`] is set,
/// [`ArgMatches::get_one`][crate::ArgMatches::get_one] will
/// return value of the environment variable.
///
/// If user doesn't set the argument in the environment:
/// - When [`Arg::action(ArgAction::Set)`] is not set, the flag is considered off.
/// - When [`Arg::action(ArgAction::Set)`] is set,
/// [`ArgMatches::get_one`][crate::ArgMatches::get_one] will
/// return the default specified.
///
/// Like with command-line values, this will be split by [`Arg::value_delimiter`].
///
/// # Examples
///
/// In this example, we show the variable coming from the environment:
///
/// ```rust
/// # use clap_builder as clap;
/// # use std::env;
/// # use clap::{Command, Arg, ArgAction};
///
/// env::set_var("MY_FLAG", "env");
///
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .env("MY_FLAG")
/// .action(ArgAction::Set))
/// .get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert_eq!(m.get_one::<String>("flag").unwrap(), "env");
/// ```
///
/// In this example, because `prog` is a flag that accepts an optional, case-insensitive
/// boolean literal.
///
/// Note that the value parser controls how flags are parsed. In this case we've selected
/// [`FalseyValueParser`][crate::builder::FalseyValueParser]. A `false` literal is `n`, `no`,
/// `f`, `false`, `off` or `0`. An absent environment variable will also be considered as
/// `false`. Anything else will considered as `true`.
///
/// ```rust
/// # use clap_builder as clap;
/// # use std::env;
/// # use clap::{Command, Arg, ArgAction};
/// # use clap::builder::FalseyValueParser;
///
/// env::set_var("TRUE_FLAG", "true");
/// env::set_var("FALSE_FLAG", "0");
///
/// let m = Command::new("prog")
/// .arg(Arg::new("true_flag")
/// .long("true_flag")
/// .action(ArgAction::SetTrue)
/// .value_parser(FalseyValueParser::new())
/// .env("TRUE_FLAG"))
/// .arg(Arg::new("false_flag")
/// .long("false_flag")
/// .action(ArgAction::SetTrue)
/// .value_parser(FalseyValueParser::new())
/// .env("FALSE_FLAG"))
/// .arg(Arg::new("absent_flag")
/// .long("absent_flag")
/// .action(ArgAction::SetTrue)
/// .value_parser(FalseyValueParser::new())
/// .env("ABSENT_FLAG"))
/// .get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert!(m.get_flag("true_flag"));
/// assert!(!m.get_flag("false_flag"));
/// assert!(!m.get_flag("absent_flag"));
/// ```
///
/// In this example, we show the variable coming from an option on the CLI:
///
/// ```rust
/// # use clap_builder as clap;
/// # use std::env;
/// # use clap::{Command, Arg, ArgAction};
///
/// env::set_var("MY_FLAG", "env");
///
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .env("MY_FLAG")
/// .action(ArgAction::Set))
/// .get_matches_from(vec![
/// "prog", "--flag", "opt"
/// ]);
///
/// assert_eq!(m.get_one::<String>("flag").unwrap(), "opt");
/// ```
///
/// In this example, we show the variable coming from the environment even with the
/// presence of a default:
///
/// ```rust
/// # use clap_builder as clap;
/// # use std::env;
/// # use clap::{Command, Arg, ArgAction};
///
/// env::set_var("MY_FLAG", "env");
///
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .env("MY_FLAG")
/// .action(ArgAction::Set)
/// .default_value("default"))
/// .get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert_eq!(m.get_one::<String>("flag").unwrap(), "env");
/// ```
///
/// In this example, we show the use of multiple values in a single environment variable:
///
/// ```rust
/// # use clap_builder as clap;
/// # use std::env;
/// # use clap::{Command, Arg, ArgAction};
///
/// env::set_var("MY_FLAG_MULTI", "env1,env2");
///
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .env("MY_FLAG_MULTI")
/// .action(ArgAction::Set)
/// .num_args(1..)
/// .value_delimiter(','))
/// .get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert_eq!(m.get_many::<String>("flag").unwrap().collect::<Vec<_>>(), vec!["env1", "env2"]);
/// ```
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
/// [`Arg::value_delimiter(',')`]: Arg::value_delimiter()
#[cfg(feature = "env")]
#[inline]
#[must_use]
pub fn env(mut self, name: impl IntoResettable<OsStr>) -> Self {
if let Some(name) = name.into_resettable().into_option() {
let value = env::var_os(&name);
self.env = Some((name, value));
} else {
self.env = None;
}
self
}
#[cfg(feature = "env")]
#[doc(hidden)]
#[cfg_attr(
feature = "deprecated",
deprecated(since = "4.0.0", note = "Replaced with `Arg::env`")
)]
pub fn env_os(self, name: impl Into<OsStr>) -> Self {
self.env(name)
}
}
/// # Help
impl Arg {
/// Sets the description of the argument for short help (`-h`).
///
/// Typically, this is a short (one line) description of the arg.
///
/// If [`Arg::long_help`] is not specified, this message will be displayed for `--help`.
///
/// **NOTE:** Only `Arg::help` is used in completion script generation in order to be concise
///
/// # Examples
///
/// Any valid UTF-8 is allowed in the help text. The one exception is when one wishes to
/// include a newline in the help text and have the following text be properly aligned with all
/// the other help text.
///
/// Setting `help` displays a short message to the side of the argument when the user passes
/// `-h` or `--help` (by default).
///
/// ```rust
/// # #[cfg(feature = "help")] {
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .long("config")
/// .help("Some help text describing the --config arg"))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
/// # }
/// ```
///
/// The above example displays
///
/// ```notrust
/// helptest
///
/// Usage: helptest [OPTIONS]
///
/// Options:
/// --config Some help text describing the --config arg
/// -h, --help Print help information
/// -V, --version Print version information
/// ```
/// [`Arg::long_help`]: Arg::long_help()
#[inline]
#[must_use]
pub fn help(mut self, h: impl IntoResettable<StyledStr>) -> Self {
self.help = h.into_resettable().into_option();
self
}
/// Sets the description of the argument for long help (`--help`).
///
/// Typically this a more detailed (multi-line) message
/// that describes the arg.
///
/// If [`Arg::help`] is not specified, this message will be displayed for `-h`.
///
/// **NOTE:** Only [`Arg::help`] is used in completion script generation in order to be concise
///
/// # Examples
///
/// Any valid UTF-8 is allowed in the help text. The one exception is when one wishes to
/// include a newline in the help text and have the following text be properly aligned with all
/// the other help text.
///
/// Setting `help` displays a short message to the side of the argument when the user passes
/// `-h` or `--help` (by default).
///
/// ```rust
/// # #[cfg(feature = "help")] {
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .long("config")
/// .long_help(
/// "The config file used by the myprog must be in JSON format
/// with only valid keys and may not contain other nonsense
/// that cannot be read by this program. Obviously I'm going on
/// and on, so I'll stop now."))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
/// # }
/// ```
///
/// The above example displays
///
/// ```text
/// prog
///
/// Usage: prog [OPTIONS]
///
/// Options:
/// --config
/// The config file used by the myprog must be in JSON format
/// with only valid keys and may not contain other nonsense
/// that cannot be read by this program. Obviously I'm going on
/// and on, so I'll stop now.
///
/// -h, --help
/// Print help information
///
/// -V, --version
/// Print version information
/// ```
/// [`Arg::help`]: Arg::help()
#[inline]
#[must_use]
pub fn long_help(mut self, h: impl IntoResettable<StyledStr>) -> Self {
self.long_help = h.into_resettable().into_option();
self
}
/// Allows custom ordering of args within the help message.
///
/// `Arg`s with a lower value will be displayed first in the help message.
/// Those with the same display order will be sorted.
///
/// `Arg`s are automatically assigned a display order based on the order they are added to the
/// [`Command`][crate::Command].
/// Overriding this is helpful when the order arguments are added in isn't the same as the
/// display order, whether in one-off cases or to automatically sort arguments.
///
/// To change, see [`Command::next_display_order`][crate::Command::next_display_order].
///
/// **NOTE:** This setting is ignored for [positional arguments] which are always displayed in
/// [index] order.
///
/// # Examples
///
/// ```rust
/// # #[cfg(feature = "help")] {
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("boat")
/// .short('b')
/// .long("boat")
/// .action(ArgAction::Set)
/// .display_order(0) // Sort
/// .help("Some help and text"))
/// .arg(Arg::new("airplane")
/// .short('a')
/// .long("airplane")
/// .action(ArgAction::Set)
/// .display_order(0) // Sort
/// .help("I should be first!"))
/// .arg(Arg::new("custom-help")
/// .short('?')
/// .action(ArgAction::Help)
/// .display_order(100) // Don't sort
/// .help("Alt help"))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
/// # }
/// ```
///
/// The above example displays the following help message
///
/// ```text
/// cust-ord
///
/// Usage: cust-ord [OPTIONS]
///
/// Options:
/// -a, --airplane <airplane> I should be first!
/// -b, --boat <boar> Some help and text
/// -h, --help Print help information
/// -? Alt help
/// ```
/// [positional arguments]: Arg::index()
/// [index]: Arg::index()
#[inline]
#[must_use]
pub fn display_order(mut self, ord: impl IntoResettable<usize>) -> Self {
self.disp_ord = ord.into_resettable().into_option();
self
}
/// Override the [current] help section.
///
/// [current]: crate::Command::next_help_heading
#[inline]
#[must_use]
pub fn help_heading(mut self, heading: impl IntoResettable<Str>) -> Self {
self.help_heading = Some(heading.into_resettable().into_option());
self
}
/// Render the [help][Arg::help] on the line after the argument.
///
/// This can be helpful for arguments with very long or complex help messages.
/// This can also be helpful for arguments with very long flag names, or many/long value names.
///
/// **NOTE:** To apply this setting to all arguments and subcommands, consider using
/// [`crate::Command::next_line_help`]
///
/// # Examples
///
/// ```rust
/// # #[cfg(feature = "help")] {
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("opt")
/// .long("long-option-flag")
/// .short('o')
/// .action(ArgAction::Set)
/// .next_line_help(true)
/// .value_names(["value1", "value2"])
/// .help("Some really long help and complex\n\
/// help that makes more sense to be\n\
/// on a line after the option"))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
/// # }
/// ```
///
/// The above example displays the following help message
///
/// ```text
/// nlh
///
/// Usage: nlh [OPTIONS]
///
/// Options:
/// -h, --help Print help information
/// -V, --version Print version information
/// -o, --long-option-flag <value1> <value2>
/// Some really long help and complex
/// help that makes more sense to be
/// on a line after the option
/// ```
#[inline]
#[must_use]
pub fn next_line_help(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::NextLineHelp)
} else {
self.unset_setting(ArgSettings::NextLineHelp)
}
}
/// Do not display the argument in help message.
///
/// **NOTE:** This does **not** hide the argument from usage strings on error
///
/// # Examples
///
/// Setting `Hidden` will hide the argument when displaying help text
///
/// ```rust
/// # #[cfg(feature = "help")] {
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .long("config")
/// .hide(true)
/// .help("Some help text describing the --config arg"))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
/// # }
/// ```
///
/// The above example displays
///
/// ```text
/// helptest
///
/// Usage: helptest [OPTIONS]
///
/// Options:
/// -h, --help Print help information
/// -V, --version Print version information
/// ```
#[inline]
#[must_use]
pub fn hide(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::Hidden)
} else {
self.unset_setting(ArgSettings::Hidden)
}
}
/// Do not display the [possible values][crate::builder::ValueParser::possible_values] in the help message.
///
/// This is useful for args with many values, or ones which are explained elsewhere in the
/// help text.
///
/// **NOTE:** Setting this requires [taking values][Arg::num_args]
///
/// To set this for all arguments, see
/// [`Command::hide_possible_values`][crate::Command::hide_possible_values].
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("mode")
/// .long("mode")
/// .value_parser(["fast", "slow"])
/// .action(ArgAction::Set)
/// .hide_possible_values(true));
/// ```
/// If we were to run the above program with `--help` the `[values: fast, slow]` portion of
/// the help text would be omitted.
#[inline]
#[must_use]
pub fn hide_possible_values(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::HidePossibleValues)
} else {
self.unset_setting(ArgSettings::HidePossibleValues)
}
}
/// Do not display the default value of the argument in the help message.
///
/// This is useful when default behavior of an arg is explained elsewhere in the help text.
///
/// **NOTE:** Setting this requires [taking values][Arg::num_args]
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("connect")
/// .arg(Arg::new("host")
/// .long("host")
/// .default_value("localhost")
/// .action(ArgAction::Set)
/// .hide_default_value(true));
///
/// ```
///
/// If we were to run the above program with `--help` the `[default: localhost]` portion of
/// the help text would be omitted.
#[inline]
#[must_use]
pub fn hide_default_value(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::HideDefaultValue)
} else {
self.unset_setting(ArgSettings::HideDefaultValue)
}
}
/// Do not display in help the environment variable name.
///
/// This is useful when the variable option is explained elsewhere in the help text.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("mode")
/// .long("mode")
/// .env("MODE")
/// .action(ArgAction::Set)
/// .hide_env(true));
/// ```
///
/// If we were to run the above program with `--help` the `[env: MODE]` portion of the help
/// text would be omitted.
#[cfg(feature = "env")]
#[inline]
#[must_use]
pub fn hide_env(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::HideEnv)
} else {
self.unset_setting(ArgSettings::HideEnv)
}
}
/// Do not display in help any values inside the associated ENV variables for the argument.
///
/// This is useful when ENV vars contain sensitive values.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("connect")
/// .arg(Arg::new("host")
/// .long("host")
/// .env("CONNECT")
/// .action(ArgAction::Set)
/// .hide_env_values(true));
///
/// ```
///
/// If we were to run the above program with `$ CONNECT=super_secret connect --help` the
/// `[default: CONNECT=super_secret]` portion of the help text would be omitted.
#[cfg(feature = "env")]
#[inline]
#[must_use]
pub fn hide_env_values(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::HideEnvValues)
} else {
self.unset_setting(ArgSettings::HideEnvValues)
}
}
/// Hides an argument from short help (`-h`).
///
/// **NOTE:** This does **not** hide the argument from usage strings on error
///
/// **NOTE:** Setting this option will cause next-line-help output style to be used
/// when long help (`--help`) is called.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// Arg::new("debug")
/// .hide_short_help(true);
/// ```
///
/// Setting `hide_short_help(true)` will hide the argument when displaying short help text
///
/// ```rust
/// # #[cfg(feature = "help")] {
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .long("config")
/// .hide_short_help(true)
/// .help("Some help text describing the --config arg"))
/// .get_matches_from(vec![
/// "prog", "-h"
/// ]);
/// # }
/// ```
///
/// The above example displays
///
/// ```text
/// helptest
///
/// Usage: helptest [OPTIONS]
///
/// Options:
/// -h, --help Print help information
/// -V, --version Print version information
/// ```
///
/// However, when --help is called
///
/// ```rust
/// # #[cfg(feature = "help")] {
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .long("config")
/// .hide_short_help(true)
/// .help("Some help text describing the --config arg"))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
/// # }
/// ```
///
/// Then the following would be displayed
///
/// ```text
/// helptest
///
/// Usage: helptest [OPTIONS]
///
/// Options:
/// --config Some help text describing the --config arg
/// -h, --help Print help information
/// -V, --version Print version information
/// ```
#[inline]
#[must_use]
pub fn hide_short_help(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::HiddenShortHelp)
} else {
self.unset_setting(ArgSettings::HiddenShortHelp)
}
}
/// Hides an argument from long help (`--help`).
///
/// **NOTE:** This does **not** hide the argument from usage strings on error
///
/// **NOTE:** Setting this option will cause next-line-help output style to be used
/// when long help (`--help`) is called.
///
/// # Examples
///
/// Setting `hide_long_help(true)` will hide the argument when displaying long help text
///
/// ```rust
/// # #[cfg(feature = "help")] {
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .long("config")
/// .hide_long_help(true)
/// .help("Some help text describing the --config arg"))
/// .get_matches_from(vec![
/// "prog", "--help"
/// ]);
/// # }
/// ```
///
/// The above example displays
///
/// ```text
/// helptest
///
/// Usage: helptest [OPTIONS]
///
/// Options:
/// -h, --help Print help information
/// -V, --version Print version information
/// ```
///
/// However, when -h is called
///
/// ```rust
/// # #[cfg(feature = "help")] {
/// # use clap_builder as clap;
/// # use clap::{Command, Arg};
/// let m = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .long("config")
/// .hide_long_help(true)
/// .help("Some help text describing the --config arg"))
/// .get_matches_from(vec![
/// "prog", "-h"
/// ]);
/// # }
/// ```
///
/// Then the following would be displayed
///
/// ```text
/// helptest
///
/// Usage: helptest [OPTIONS]
///
/// OPTIONS:
/// --config Some help text describing the --config arg
/// -h, --help Print help information
/// -V, --version Print version information
/// ```
#[inline]
#[must_use]
pub fn hide_long_help(self, yes: bool) -> Self {
if yes {
self.setting(ArgSettings::HiddenLongHelp)
} else {
self.unset_setting(ArgSettings::HiddenLongHelp)
}
}
}
/// # Advanced Argument Relations
impl Arg {
/// The name of the [`ArgGroup`] the argument belongs to.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// Arg::new("debug")
/// .long("debug")
/// .action(ArgAction::SetTrue)
/// .group("mode")
/// # ;
/// ```
///
/// Multiple arguments can be a member of a single group and then the group checked as if it
/// was one of said arguments.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("debug")
/// .long("debug")
/// .action(ArgAction::SetTrue)
/// .group("mode"))
/// .arg(Arg::new("verbose")
/// .long("verbose")
/// .action(ArgAction::SetTrue)
/// .group("mode"))
/// .get_matches_from(vec![
/// "prog", "--debug"
/// ]);
/// assert!(m.contains_id("mode"));
/// ```
///
/// [`ArgGroup`]: crate::ArgGroup
#[must_use]
pub fn group(mut self, group_id: impl IntoResettable<Id>) -> Self {
if let Some(group_id) = group_id.into_resettable().into_option() {
self.groups.push(group_id);
} else {
self.groups.clear();
}
self
}
/// The names of [`ArgGroup`]'s the argument belongs to.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// Arg::new("debug")
/// .long("debug")
/// .action(ArgAction::SetTrue)
/// .groups(["mode", "verbosity"])
/// # ;
/// ```
///
/// Arguments can be members of multiple groups and then the group checked as if it
/// was one of said arguments.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("debug")
/// .long("debug")
/// .action(ArgAction::SetTrue)
/// .groups(["mode", "verbosity"]))
/// .arg(Arg::new("verbose")
/// .long("verbose")
/// .action(ArgAction::SetTrue)
/// .groups(["mode", "verbosity"]))
/// .get_matches_from(vec![
/// "prog", "--debug"
/// ]);
/// assert!(m.contains_id("mode"));
/// assert!(m.contains_id("verbosity"));
/// ```
///
/// [`ArgGroup`]: crate::ArgGroup
#[must_use]
pub fn groups(mut self, group_ids: impl IntoIterator<Item = impl Into<Id>>) -> Self {
self.groups.extend(group_ids.into_iter().map(Into::into));
self
}
/// Specifies the value of the argument if `arg` has been used at runtime.
///
/// If `default` is set to `None`, `default_value` will be removed.
///
/// **NOTE:** This setting is perfectly compatible with [`Arg::default_value`] but slightly
/// different. `Arg::default_value` *only* takes effect when the user has not provided this arg
/// at runtime. This setting however only takes effect when the user has not provided a value at
/// runtime **and** these other conditions are met as well. If you have set `Arg::default_value`
/// and `Arg::default_value_if`, and the user **did not** provide this arg at runtime, nor were
/// the conditions met for `Arg::default_value_if`, the `Arg::default_value` will be applied.
///
/// Like with command-line values, this will be split by [`Arg::value_delimiter`].
///
/// # Examples
///
/// First we use the default value only if another arg is present at runtime.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// # use clap::builder::{ArgPredicate};
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("other")
/// .long("other")
/// .default_value_if("flag", ArgPredicate::IsPresent, Some("default")))
/// .get_matches_from(vec![
/// "prog", "--flag"
/// ]);
///
/// assert_eq!(m.get_one::<String>("other").unwrap(), "default");
/// ```
///
/// Next we run the same test, but without providing `--flag`.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("other")
/// .long("other")
/// .default_value_if("flag", "true", Some("default")))
/// .get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert_eq!(m.get_one::<String>("other"), None);
/// ```
///
/// Now lets only use the default value if `--opt` contains the value `special`.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("opt")
/// .action(ArgAction::Set)
/// .long("opt"))
/// .arg(Arg::new("other")
/// .long("other")
/// .default_value_if("opt", "special", Some("default")))
/// .get_matches_from(vec![
/// "prog", "--opt", "special"
/// ]);
///
/// assert_eq!(m.get_one::<String>("other").unwrap(), "default");
/// ```
///
/// We can run the same test and provide any value *other than* `special` and we won't get a
/// default value.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("opt")
/// .action(ArgAction::Set)
/// .long("opt"))
/// .arg(Arg::new("other")
/// .long("other")
/// .default_value_if("opt", "special", Some("default")))
/// .get_matches_from(vec![
/// "prog", "--opt", "hahaha"
/// ]);
///
/// assert_eq!(m.get_one::<String>("other"), None);
/// ```
///
/// If we want to unset the default value for an Arg based on the presence or
/// value of some other Arg.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("other")
/// .long("other")
/// .default_value("default")
/// .default_value_if("flag", "true", None))
/// .get_matches_from(vec![
/// "prog", "--flag"
/// ]);
///
/// assert_eq!(m.get_one::<String>("other"), None);
/// ```
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
/// [`Arg::default_value`]: Arg::default_value()
#[must_use]
pub fn default_value_if(
mut self,
arg_id: impl Into<Id>,
predicate: impl Into<ArgPredicate>,
default: impl IntoResettable<OsStr>,
) -> Self {
self.default_vals_ifs.push((
arg_id.into(),
predicate.into(),
default.into_resettable().into_option(),
));
self
}
#[must_use]
#[doc(hidden)]
#[cfg_attr(
feature = "deprecated",
deprecated(since = "4.0.0", note = "Replaced with `Arg::default_value_if`")
)]
pub fn default_value_if_os(
self,
arg_id: impl Into<Id>,
predicate: impl Into<ArgPredicate>,
default: impl IntoResettable<OsStr>,
) -> Self {
self.default_value_if(arg_id, predicate, default)
}
/// Specifies multiple values and conditions in the same manner as [`Arg::default_value_if`].
///
/// The method takes a slice of tuples in the `(arg, predicate, default)` format.
///
/// **NOTE**: The conditions are stored in order and evaluated in the same order. I.e. the first
/// if multiple conditions are true, the first one found will be applied and the ultimate value.
///
/// Like with command-line values, this will be split by [`Arg::value_delimiter`].
///
/// # Examples
///
/// First we use the default value only if another arg is present at runtime.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("opt")
/// .long("opt")
/// .action(ArgAction::Set))
/// .arg(Arg::new("other")
/// .long("other")
/// .default_value_ifs([
/// ("flag", "true", Some("default")),
/// ("opt", "channal", Some("chan")),
/// ]))
/// .get_matches_from(vec![
/// "prog", "--opt", "channal"
/// ]);
///
/// assert_eq!(m.get_one::<String>("other").unwrap(), "chan");
/// ```
///
/// Next we run the same test, but without providing `--flag`.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("other")
/// .long("other")
/// .default_value_ifs([
/// ("flag", "true", Some("default")),
/// ("opt", "channal", Some("chan")),
/// ]))
/// .get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert_eq!(m.get_one::<String>("other"), None);
/// ```
///
/// We can also see that these values are applied in order, and if more than one condition is
/// true, only the first evaluated "wins"
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// # use clap::builder::ArgPredicate;
/// let m = Command::new("prog")
/// .arg(Arg::new("flag")
/// .long("flag")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("opt")
/// .long("opt")
/// .action(ArgAction::Set))
/// .arg(Arg::new("other")
/// .long("other")
/// .default_value_ifs([
/// ("flag", ArgPredicate::IsPresent, Some("default")),
/// ("opt", ArgPredicate::Equals("channal".into()), Some("chan")),
/// ]))
/// .get_matches_from(vec![
/// "prog", "--opt", "channal", "--flag"
/// ]);
///
/// assert_eq!(m.get_one::<String>("other").unwrap(), "default");
/// ```
/// [`Arg::action(ArgAction::Set)`]: Arg::action()
/// [`Arg::default_value_if`]: Arg::default_value_if()
#[must_use]
pub fn default_value_ifs(
mut self,
ifs: impl IntoIterator<
Item = (
impl Into<Id>,
impl Into<ArgPredicate>,
impl IntoResettable<OsStr>,
),
>,
) -> Self {
for (arg, predicate, default) in ifs {
self = self.default_value_if(arg, predicate, default);
}
self
}
#[must_use]
#[doc(hidden)]
#[cfg_attr(
feature = "deprecated",
deprecated(since = "4.0.0", note = "Replaced with `Arg::default_value_ifs`")
)]
pub fn default_value_ifs_os(
self,
ifs: impl IntoIterator<
Item = (
impl Into<Id>,
impl Into<ArgPredicate>,
impl IntoResettable<OsStr>,
),
>,
) -> Self {
self.default_value_ifs(ifs)
}
/// Set this arg as [required] as long as the specified argument is not present at runtime.
///
/// **Pro Tip:** Using `Arg::required_unless_present` implies [`Arg::required`] and is therefore not
/// mandatory to also set.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .required_unless_present("debug")
/// # ;
/// ```
///
/// In the following example, the required argument is *not* provided,
/// but it's not an error because the `unless` arg has been supplied.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_unless_present("dbg")
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("dbg")
/// .long("debug")
/// .action(ArgAction::SetTrue))
/// .try_get_matches_from(vec![
/// "prog", "--debug"
/// ]);
///
/// assert!(res.is_ok());
/// ```
///
/// Setting `Arg::required_unless_present(name)` and *not* supplying `name` or this arg is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_unless_present("dbg")
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("dbg")
/// .long("debug"))
/// .try_get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
/// [required]: Arg::required()
#[must_use]
pub fn required_unless_present(mut self, arg_id: impl IntoResettable<Id>) -> Self {
if let Some(arg_id) = arg_id.into_resettable().into_option() {
self.r_unless.push(arg_id);
} else {
self.r_unless.clear();
}
self
}
/// Sets this arg as [required] unless *all* of the specified arguments are present at runtime.
///
/// In other words, parsing will succeed only if user either
/// * supplies the `self` arg.
/// * supplies *all* of the `names` arguments.
///
/// **NOTE:** If you wish for this argument to only be required unless *any of* these args are
/// present see [`Arg::required_unless_present_any`]
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .required_unless_present_all(["cfg", "dbg"])
/// # ;
/// ```
///
/// In the following example, the required argument is *not* provided, but it's not an error
/// because *all* of the `names` args have been supplied.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_unless_present_all(["dbg", "infile"])
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("dbg")
/// .long("debug")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("infile")
/// .short('i')
/// .action(ArgAction::Set))
/// .try_get_matches_from(vec![
/// "prog", "--debug", "-i", "file"
/// ]);
///
/// assert!(res.is_ok());
/// ```
///
/// Setting [`Arg::required_unless_present_all(names)`] and *not* supplying
/// either *all* of `unless` args or the `self` arg is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_unless_present_all(["dbg", "infile"])
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("dbg")
/// .long("debug")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("infile")
/// .short('i')
/// .action(ArgAction::Set))
/// .try_get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
/// [required]: Arg::required()
/// [`Arg::required_unless_present_any`]: Arg::required_unless_present_any()
/// [`Arg::required_unless_present_all(names)`]: Arg::required_unless_present_all()
#[must_use]
pub fn required_unless_present_all(
mut self,
names: impl IntoIterator<Item = impl Into<Id>>,
) -> Self {
self.r_unless_all.extend(names.into_iter().map(Into::into));
self
}
/// Sets this arg as [required] unless *any* of the specified arguments are present at runtime.
///
/// In other words, parsing will succeed only if user either
/// * supplies the `self` arg.
/// * supplies *one or more* of the `unless` arguments.
///
/// **NOTE:** If you wish for this argument to be required unless *all of* these args are
/// present see [`Arg::required_unless_present_all`]
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .required_unless_present_any(["cfg", "dbg"])
/// # ;
/// ```
///
/// Setting [`Arg::required_unless_present_any(names)`] requires that the argument be used at runtime
/// *unless* *at least one of* the args in `names` are present. In the following example, the
/// required argument is *not* provided, but it's not an error because one the `unless` args
/// have been supplied.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_unless_present_any(["dbg", "infile"])
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("dbg")
/// .long("debug")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("infile")
/// .short('i')
/// .action(ArgAction::Set))
/// .try_get_matches_from(vec![
/// "prog", "--debug"
/// ]);
///
/// assert!(res.is_ok());
/// ```
///
/// Setting [`Arg::required_unless_present_any(names)`] and *not* supplying *at least one of* `names`
/// or this arg is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_unless_present_any(["dbg", "infile"])
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("dbg")
/// .long("debug")
/// .action(ArgAction::SetTrue))
/// .arg(Arg::new("infile")
/// .short('i')
/// .action(ArgAction::Set))
/// .try_get_matches_from(vec![
/// "prog"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
/// [required]: Arg::required()
/// [`Arg::required_unless_present_any(names)`]: Arg::required_unless_present_any()
/// [`Arg::required_unless_present_all`]: Arg::required_unless_present_all()
#[must_use]
pub fn required_unless_present_any(
mut self,
names: impl IntoIterator<Item = impl Into<Id>>,
) -> Self {
self.r_unless.extend(names.into_iter().map(Into::into));
self
}
/// This argument is [required] only if the specified `arg` is present at runtime and its value
/// equals `val`.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .required_if_eq("other_arg", "value")
/// # ;
/// ```
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .required_if_eq("other", "special")
/// .long("config"))
/// .arg(Arg::new("other")
/// .long("other")
/// .action(ArgAction::Set))
/// .try_get_matches_from(vec![
/// "prog", "--other", "not-special"
/// ]);
///
/// assert!(res.is_ok()); // We didn't use --other=special, so "cfg" wasn't required
///
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .required_if_eq("other", "special")
/// .long("config"))
/// .arg(Arg::new("other")
/// .long("other")
/// .action(ArgAction::Set))
/// .try_get_matches_from(vec![
/// "prog", "--other", "special"
/// ]);
///
/// // We did use --other=special so "cfg" had become required but was missing.
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
///
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .required_if_eq("other", "special")
/// .long("config"))
/// .arg(Arg::new("other")
/// .long("other")
/// .action(ArgAction::Set))
/// .try_get_matches_from(vec![
/// "prog", "--other", "SPECIAL"
/// ]);
///
/// // By default, the comparison is case-sensitive, so "cfg" wasn't required
/// assert!(res.is_ok());
///
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .required_if_eq("other", "special")
/// .long("config"))
/// .arg(Arg::new("other")
/// .long("other")
/// .ignore_case(true)
/// .action(ArgAction::Set))
/// .try_get_matches_from(vec![
/// "prog", "--other", "SPECIAL"
/// ]);
///
/// // However, case-insensitive comparisons can be enabled. This typically occurs when using Arg::possible_values().
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
/// [`Arg::requires(name)`]: Arg::requires()
/// [Conflicting]: Arg::conflicts_with()
/// [required]: Arg::required()
#[must_use]
pub fn required_if_eq(mut self, arg_id: impl Into<Id>, val: impl Into<OsStr>) -> Self {
self.r_ifs.push((arg_id.into(), val.into()));
self
}
/// Specify this argument is [required] based on multiple conditions.
///
/// The conditions are set up in a `(arg, val)` style tuple. The requirement will only become
/// valid if one of the specified `arg`'s value equals its corresponding `val`.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .required_if_eq_any([
/// ("extra", "val"),
/// ("option", "spec")
/// ])
/// # ;
/// ```
///
/// Setting `Arg::required_if_eq_any([(arg, val)])` makes this arg required if any of the `arg`s
/// are used at runtime and it's corresponding value is equal to `val`. If the `arg`'s value is
/// anything other than `val`, this argument isn't required.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_if_eq_any([
/// ("extra", "val"),
/// ("option", "spec")
/// ])
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("extra")
/// .action(ArgAction::Set)
/// .long("extra"))
/// .arg(Arg::new("option")
/// .action(ArgAction::Set)
/// .long("option"))
/// .try_get_matches_from(vec![
/// "prog", "--option", "other"
/// ]);
///
/// assert!(res.is_ok()); // We didn't use --option=spec, or --extra=val so "cfg" isn't required
/// ```
///
/// Setting `Arg::required_if_eq_any([(arg, val)])` and having any of the `arg`s used with its
/// value of `val` but *not* using this arg is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_if_eq_any([
/// ("extra", "val"),
/// ("option", "spec")
/// ])
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("extra")
/// .action(ArgAction::Set)
/// .long("extra"))
/// .arg(Arg::new("option")
/// .action(ArgAction::Set)
/// .long("option"))
/// .try_get_matches_from(vec![
/// "prog", "--option", "spec"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
/// [`Arg::requires(name)`]: Arg::requires()
/// [Conflicting]: Arg::conflicts_with()
/// [required]: Arg::required()
#[must_use]
pub fn required_if_eq_any(
mut self,
ifs: impl IntoIterator<Item = (impl Into<Id>, impl Into<OsStr>)>,
) -> Self {
self.r_ifs
.extend(ifs.into_iter().map(|(id, val)| (id.into(), val.into())));
self
}
/// Specify this argument is [required] based on multiple conditions.
///
/// The conditions are set up in a `(arg, val)` style tuple. The requirement will only become
/// valid if every one of the specified `arg`'s value equals its corresponding `val`.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .required_if_eq_all([
/// ("extra", "val"),
/// ("option", "spec")
/// ])
/// # ;
/// ```
///
/// Setting `Arg::required_if_eq_all([(arg, val)])` makes this arg required if all of the `arg`s
/// are used at runtime and every value is equal to its corresponding `val`. If the `arg`'s value is
/// anything other than `val`, this argument isn't required.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_if_eq_all([
/// ("extra", "val"),
/// ("option", "spec")
/// ])
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("extra")
/// .action(ArgAction::Set)
/// .long("extra"))
/// .arg(Arg::new("option")
/// .action(ArgAction::Set)
/// .long("option"))
/// .try_get_matches_from(vec![
/// "prog", "--option", "spec"
/// ]);
///
/// assert!(res.is_ok()); // We didn't use --option=spec --extra=val so "cfg" isn't required
/// ```
///
/// Setting `Arg::required_if_eq_all([(arg, val)])` and having all of the `arg`s used with its
/// value of `val` but *not* using this arg is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .required_if_eq_all([
/// ("extra", "val"),
/// ("option", "spec")
/// ])
/// .action(ArgAction::Set)
/// .long("config"))
/// .arg(Arg::new("extra")
/// .action(ArgAction::Set)
/// .long("extra"))
/// .arg(Arg::new("option")
/// .action(ArgAction::Set)
/// .long("option"))
/// .try_get_matches_from(vec![
/// "prog", "--extra", "val", "--option", "spec"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
/// [required]: Arg::required()
#[must_use]
pub fn required_if_eq_all(
mut self,
ifs: impl IntoIterator<Item = (impl Into<Id>, impl Into<OsStr>)>,
) -> Self {
self.r_ifs_all
.extend(ifs.into_iter().map(|(id, val)| (id.into(), val.into())));
self
}
/// Require another argument if this arg matches the [`ArgPredicate`]
///
/// This method takes `value, another_arg` pair. At runtime, clap will check
/// if this arg (`self`) matches the [`ArgPredicate`].
/// If it does, `another_arg` will be marked as required.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .requires_if("val", "arg")
/// # ;
/// ```
///
/// Setting `Arg::requires_if(val, arg)` requires that the `arg` be used at runtime if the
/// defining argument's value is equal to `val`. If the defining argument is anything other than
/// `val`, the other argument isn't required.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .requires_if("my.cfg", "other")
/// .long("config"))
/// .arg(Arg::new("other"))
/// .try_get_matches_from(vec![
/// "prog", "--config", "some.cfg"
/// ]);
///
/// assert!(res.is_ok()); // We didn't use --config=my.cfg, so other wasn't required
/// ```
///
/// Setting `Arg::requires_if(val, arg)` and setting the value to `val` but *not* supplying
/// `arg` is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .requires_if("my.cfg", "input")
/// .long("config"))
/// .arg(Arg::new("input"))
/// .try_get_matches_from(vec![
/// "prog", "--config", "my.cfg"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
/// [`Arg::requires(name)`]: Arg::requires()
/// [Conflicting]: Arg::conflicts_with()
/// [override]: Arg::overrides_with()
#[must_use]
pub fn requires_if(mut self, val: impl Into<ArgPredicate>, arg_id: impl Into<Id>) -> Self {
self.requires.push((val.into(), arg_id.into()));
self
}
/// Allows multiple conditional requirements.
///
/// The requirement will only become valid if this arg's value matches the
/// [`ArgPredicate`].
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .requires_ifs([
/// ("val", "arg"),
/// ("other_val", "arg2"),
/// ])
/// # ;
/// ```
///
/// Setting `Arg::requires_ifs(["val", "arg"])` requires that the `arg` be used at runtime if the
/// defining argument's value is equal to `val`. If the defining argument's value is anything other
/// than `val`, `arg` isn't required.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .requires_ifs([
/// ("special.conf", "opt"),
/// ("other.conf", "other"),
/// ])
/// .long("config"))
/// .arg(Arg::new("opt")
/// .long("option")
/// .action(ArgAction::Set))
/// .arg(Arg::new("other"))
/// .try_get_matches_from(vec![
/// "prog", "--config", "special.conf"
/// ]);
///
/// assert!(res.is_err()); // We used --config=special.conf so --option <val> is required
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
///
/// Setting `Arg::requires_ifs` with [`ArgPredicate::IsPresent`] and *not* supplying all the
/// arguments is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction, builder::ArgPredicate};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .requires_ifs([
/// (ArgPredicate::IsPresent, "input"),
/// (ArgPredicate::IsPresent, "output"),
/// ])
/// .long("config"))
/// .arg(Arg::new("input"))
/// .arg(Arg::new("output"))
/// .try_get_matches_from(vec![
/// "prog", "--config", "file.conf", "in.txt"
/// ]);
///
/// assert!(res.is_err());
/// // We didn't use output
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::MissingRequiredArgument);
/// ```
///
/// [`Arg::requires(name)`]: Arg::requires()
/// [Conflicting]: Arg::conflicts_with()
/// [override]: Arg::overrides_with()
#[must_use]
pub fn requires_ifs(
mut self,
ifs: impl IntoIterator<Item = (impl Into<ArgPredicate>, impl Into<Id>)>,
) -> Self {
self.requires
.extend(ifs.into_iter().map(|(val, arg)| (val.into(), arg.into())));
self
}
#[doc(hidden)]
#[cfg_attr(
feature = "deprecated",
deprecated(since = "4.0.0", note = "Replaced with `Arg::requires_ifs`")
)]
pub fn requires_all(self, ids: impl IntoIterator<Item = impl Into<Id>>) -> Self {
self.requires_ifs(ids.into_iter().map(|id| (ArgPredicate::IsPresent, id)))
}
/// This argument is mutually exclusive with the specified argument.
///
/// **NOTE:** Conflicting rules take precedence over being required by default. Conflict rules
/// only need to be set for one of the two arguments, they do not need to be set for each.
///
/// **NOTE:** Defining a conflict is two-way, but does *not* need to defined for both arguments
/// (i.e. if A conflicts with B, defining `A.conflicts_with(B)` is sufficient. You do not
/// need to also do `B.conflicts_with(A)`)
///
/// **NOTE:** [`Arg::conflicts_with_all(names)`] allows specifying an argument which conflicts with more than one argument.
///
/// **NOTE** [`Arg::exclusive(true)`] allows specifying an argument which conflicts with every other argument.
///
/// **NOTE:** All arguments implicitly conflict with themselves.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .conflicts_with("debug")
/// # ;
/// ```
///
/// Setting conflicting argument, and having both arguments present at runtime is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .conflicts_with("debug")
/// .long("config"))
/// .arg(Arg::new("debug")
/// .long("debug")
/// .action(ArgAction::SetTrue))
/// .try_get_matches_from(vec![
/// "prog", "--debug", "--config", "file.conf"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::ArgumentConflict);
/// ```
///
/// [`Arg::conflicts_with_all(names)`]: Arg::conflicts_with_all()
/// [`Arg::exclusive(true)`]: Arg::exclusive()
#[must_use]
pub fn conflicts_with(mut self, arg_id: impl IntoResettable<Id>) -> Self {
if let Some(arg_id) = arg_id.into_resettable().into_option() {
self.blacklist.push(arg_id);
} else {
self.blacklist.clear();
}
self
}
/// This argument is mutually exclusive with the specified arguments.
///
/// See [`Arg::conflicts_with`].
///
/// **NOTE:** Conflicting rules take precedence over being required by default. Conflict rules
/// only need to be set for one of the two arguments, they do not need to be set for each.
///
/// **NOTE:** Defining a conflict is two-way, but does *not* need to defined for both arguments
/// (i.e. if A conflicts with B, defining `A.conflicts_with(B)` is sufficient. You do not need
/// need to also do `B.conflicts_with(A)`)
///
/// **NOTE:** [`Arg::exclusive(true)`] allows specifying an argument which conflicts with every other argument.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// Arg::new("config")
/// .conflicts_with_all(["debug", "input"])
/// # ;
/// ```
///
/// Setting conflicting argument, and having any of the arguments present at runtime with a
/// conflicting argument is an error.
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, Arg, error::ErrorKind, ArgAction};
/// let res = Command::new("prog")
/// .arg(Arg::new("cfg")
/// .action(ArgAction::Set)
/// .conflicts_with_all(["debug", "input"])
/// .long("config"))
/// .arg(Arg::new("debug")
/// .long("debug"))
/// .arg(Arg::new("input"))
/// .try_get_matches_from(vec![
/// "prog", "--config", "file.conf", "file.txt"
/// ]);
///
/// assert!(res.is_err());
/// assert_eq!(res.unwrap_err().kind(), ErrorKind::ArgumentConflict);
/// ```
/// [`Arg::conflicts_with`]: Arg::conflicts_with()
/// [`Arg::exclusive(true)`]: Arg::exclusive()
#[must_use]
pub fn conflicts_with_all(mut self, names: impl IntoIterator<Item = impl Into<Id>>) -> Self {
self.blacklist.extend(names.into_iter().map(Into::into));
self
}
/// Sets an overridable argument.
///
/// i.e. this argument and the following argument
/// will override each other in POSIX style (whichever argument was specified at runtime
/// **last** "wins")
///
/// **NOTE:** When an argument is overridden it is essentially as if it never was used, any
/// conflicts, requirements, etc. are evaluated **after** all "overrides" have been removed
///
/// **NOTE:** Overriding an argument implies they [conflict][Arg::conflicts_with`].
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, arg};
/// let m = Command::new("prog")
/// .arg(arg!(-f --flag "some flag")
/// .conflicts_with("debug"))
/// .arg(arg!(-d --debug "other flag"))
/// .arg(arg!(-c --color "third flag")
/// .overrides_with("flag"))
/// .get_matches_from(vec![
/// "prog", "-f", "-d", "-c"]);
/// // ^~~~~~~~~~~~^~~~~ flag is overridden by color
///
/// assert!(m.get_flag("color"));
/// assert!(m.get_flag("debug")); // even though flag conflicts with debug, it's as if flag
/// // was never used because it was overridden with color
/// assert!(!m.get_flag("flag"));
/// ```
#[must_use]
pub fn overrides_with(mut self, arg_id: impl IntoResettable<Id>) -> Self {
if let Some(arg_id) = arg_id.into_resettable().into_option() {
self.overrides.push(arg_id);
} else {
self.overrides.clear();
}
self
}
/// Sets multiple mutually overridable arguments by name.
///
/// i.e. this argument and the following argument will override each other in POSIX style
/// (whichever argument was specified at runtime **last** "wins")
///
/// **NOTE:** When an argument is overridden it is essentially as if it never was used, any
/// conflicts, requirements, etc. are evaluated **after** all "overrides" have been removed
///
/// **NOTE:** Overriding an argument implies they [conflict][Arg::conflicts_with_all`].
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::{Command, arg};
/// let m = Command::new("prog")
/// .arg(arg!(-f --flag "some flag")
/// .conflicts_with("color"))
/// .arg(arg!(-d --debug "other flag"))
/// .arg(arg!(-c --color "third flag")
/// .overrides_with_all(["flag", "debug"]))
/// .get_matches_from(vec![
/// "prog", "-f", "-d", "-c"]);
/// // ^~~~~~^~~~~~~~~ flag and debug are overridden by color
///
/// assert!(m.get_flag("color")); // even though flag conflicts with color, it's as if flag
/// // and debug were never used because they were overridden
/// // with color
/// assert!(!m.get_flag("debug"));
/// assert!(!m.get_flag("flag"));
/// ```
#[must_use]
pub fn overrides_with_all(mut self, names: impl IntoIterator<Item = impl Into<Id>>) -> Self {
self.overrides.extend(names.into_iter().map(Into::into));
self
}
}
/// # Reflection
impl Arg {
/// Get the name of the argument
#[inline]
pub fn get_id(&self) -> &Id {
&self.id
}
/// Get the help specified for this argument, if any
#[inline]
pub fn get_help(&self) -> Option<&StyledStr> {
self.help.as_ref()
}
/// Get the long help specified for this argument, if any
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// let arg = Arg::new("foo").long_help("long help");
/// assert_eq!(Some("long help".to_owned()), arg.get_long_help().map(|s| s.to_string()));
/// ```
///
#[inline]
pub fn get_long_help(&self) -> Option<&StyledStr> {
self.long_help.as_ref()
}
/// Get the help heading specified for this argument, if any
#[inline]
pub fn get_help_heading(&self) -> Option<&str> {
self.help_heading
.as_ref()
.map(|s| s.as_deref())
.unwrap_or_default()
}
/// Get the short option name for this argument, if any
#[inline]
pub fn get_short(&self) -> Option<char> {
self.short
}
/// Get visible short aliases for this argument, if any
#[inline]
pub fn get_visible_short_aliases(&self) -> Option<Vec<char>> {
if self.short_aliases.is_empty() {
None
} else {
Some(
self.short_aliases
.iter()
.filter_map(|(c, v)| if *v { Some(c) } else { None })
.copied()
.collect(),
)
}
}
/// Get *all* short aliases for this argument, if any, both visible and hidden.
#[inline]
pub fn get_all_short_aliases(&self) -> Option<Vec<char>> {
if self.short_aliases.is_empty() {
None
} else {
Some(self.short_aliases.iter().map(|(s, _)| s).copied().collect())
}
}
/// Get the short option name and its visible aliases, if any
#[inline]
pub fn get_short_and_visible_aliases(&self) -> Option<Vec<char>> {
let mut shorts = match self.short {
Some(short) => vec![short],
None => return None,
};
if let Some(aliases) = self.get_visible_short_aliases() {
shorts.extend(aliases);
}
Some(shorts)
}
/// Get the long option name for this argument, if any
#[inline]
pub fn get_long(&self) -> Option<&str> {
self.long.as_deref()
}
/// Get visible aliases for this argument, if any
#[inline]
pub fn get_visible_aliases(&self) -> Option<Vec<&str>> {
if self.aliases.is_empty() {
None
} else {
Some(
self.aliases
.iter()
.filter_map(|(s, v)| if *v { Some(s.as_str()) } else { None })
.collect(),
)
}
}
/// Get *all* aliases for this argument, if any, both visible and hidden.
#[inline]
pub fn get_all_aliases(&self) -> Option<Vec<&str>> {
if self.aliases.is_empty() {
None
} else {
Some(self.aliases.iter().map(|(s, _)| s.as_str()).collect())
}
}
/// Get the long option name and its visible aliases, if any
#[inline]
pub fn get_long_and_visible_aliases(&self) -> Option<Vec<&str>> {
let mut longs = match self.get_long() {
Some(long) => vec![long],
None => return None,
};
if let Some(aliases) = self.get_visible_aliases() {
longs.extend(aliases);
}
Some(longs)
}
/// Get hidden aliases for this argument, if any
#[inline]
pub fn get_aliases(&self) -> Option<Vec<&str>> {
if self.aliases.is_empty() {
None
} else {
Some(
self.aliases
.iter()
.filter_map(|(s, v)| if !*v { Some(s.as_str()) } else { None })
.collect(),
)
}
}
/// Get the names of possible values for this argument. Only useful for user
/// facing applications, such as building help messages or man files
pub fn get_possible_values(&self) -> Vec<PossibleValue> {
if !self.is_takes_value_set() {
vec![]
} else {
self.get_value_parser()
.possible_values()
.map(|pvs| pvs.collect())
.unwrap_or_default()
}
}
/// Get the names of values for this argument.
#[inline]
pub fn get_value_names(&self) -> Option<&[Str]> {
if self.val_names.is_empty() {
None
} else {
Some(&self.val_names)
}
}
/// Get the number of values for this argument.
#[inline]
pub fn get_num_args(&self) -> Option<ValueRange> {
self.num_vals
}
#[inline]
pub(crate) fn get_min_vals(&self) -> usize {
self.get_num_args().expect(INTERNAL_ERROR_MSG).min_values()
}
/// Get the delimiter between multiple values
#[inline]
pub fn get_value_delimiter(&self) -> Option<char> {
self.val_delim
}
/// Get the value terminator for this argument. The `value_terminator` is a value
/// that terminates parsing of multi-valued arguments.
#[inline]
pub fn get_value_terminator(&self) -> Option<&Str> {
self.terminator.as_ref()
}
/// Get the index of this argument, if any
#[inline]
pub fn get_index(&self) -> Option<usize> {
self.index
}
/// Get the value hint of this argument
pub fn get_value_hint(&self) -> ValueHint {
// HACK: we should use `Self::add` and `Self::remove` to type-check that `ArgExt` is used
self.ext.get::<ValueHint>().copied().unwrap_or_else(|| {
if self.is_takes_value_set() {
let type_id = self.get_value_parser().type_id();
if type_id == AnyValueId::of::<std::path::PathBuf>() {
ValueHint::AnyPath
} else {
ValueHint::default()
}
} else {
ValueHint::default()
}
})
}
/// Get the environment variable name specified for this argument, if any
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use std::ffi::OsStr;
/// # use clap::Arg;
/// let arg = Arg::new("foo").env("ENVIRONMENT");
/// assert_eq!(arg.get_env(), Some(OsStr::new("ENVIRONMENT")));
/// ```
#[cfg(feature = "env")]
pub fn get_env(&self) -> Option<&std::ffi::OsStr> {
self.env.as_ref().map(|x| x.0.as_os_str())
}
/// Get the default values specified for this argument, if any
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// let arg = Arg::new("foo").default_value("default value");
/// assert_eq!(arg.get_default_values(), &["default value"]);
/// ```
pub fn get_default_values(&self) -> &[OsStr] {
&self.default_vals
}
/// Checks whether this argument is a positional or not.
///
/// # Examples
///
/// ```rust
/// # use clap_builder as clap;
/// # use clap::Arg;
/// let arg = Arg::new("foo");
/// assert_eq!(arg.is_positional(), true);
///
/// let arg = Arg::new("foo").long("foo");
/// assert_eq!(arg.is_positional(), false);
/// ```
pub fn is_positional(&self) -> bool {
self.get_long().is_none() && self.get_short().is_none()
}
/// Reports whether [`Arg::required`] is set
pub fn is_required_set(&self) -> bool {
self.is_set(ArgSettings::Required)
}
pub(crate) fn is_multiple_values_set(&self) -> bool {
self.get_num_args().unwrap_or_default().is_multiple()
}
pub(crate) fn is_takes_value_set(&self) -> bool {
self.get_num_args()
.unwrap_or_else(|| 1.into())
.takes_values()
}
/// Report whether [`Arg::allow_hyphen_values`] is set
pub fn is_allow_hyphen_values_set(&self) -> bool {
self.is_set(ArgSettings::AllowHyphenValues)
}
/// Report whether [`Arg::allow_negative_numbers`] is set
pub fn is_allow_negative_numbers_set(&self) -> bool {
self.is_set(ArgSettings::AllowNegativeNumbers)
}
/// Behavior when parsing the argument
pub fn get_action(&self) -> &ArgAction {
const DEFAULT: ArgAction = ArgAction::Set;
self.action.as_ref().unwrap_or(&DEFAULT)
}
/// Configured parser for argument values
///
/// # Example
///
/// ```rust
/// # use clap_builder as clap;
/// let cmd = clap::Command::new("raw")
/// .arg(
/// clap::Arg::new("port")
/// .value_parser(clap::value_parser!(usize))
/// );
/// let value_parser = cmd.get_arguments()
/// .find(|a| a.get_id() == "port").unwrap()
/// .get_value_parser();
/// println!("{value_parser:?}");
/// ```
pub fn get_value_parser(&self) -> &super::ValueParser {
if let Some(value_parser) = self.value_parser.as_ref() {
value_parser
} else {
static DEFAULT: super::ValueParser = super::ValueParser::string();
&DEFAULT
}
}
/// Report whether [`Arg::global`] is set
pub fn is_global_set(&self) -> bool {
self.is_set(ArgSettings::Global)
}
/// Report whether [`Arg::next_line_help`] is set
pub fn is_next_line_help_set(&self) -> bool {
self.is_set(ArgSettings::NextLineHelp)
}
/// Report whether [`Arg::hide`] is set
pub fn is_hide_set(&self) -> bool {
self.is_set(ArgSettings::Hidden)
}
/// Report whether [`Arg::hide_default_value`] is set
pub fn is_hide_default_value_set(&self) -> bool {
self.is_set(ArgSettings::HideDefaultValue)
}
/// Report whether [`Arg::hide_possible_values`] is set
pub fn is_hide_possible_values_set(&self) -> bool {
self.is_set(ArgSettings::HidePossibleValues)
}
/// Report whether [`Arg::hide_env`] is set
#[cfg(feature = "env")]
pub fn is_hide_env_set(&self) -> bool {
self.is_set(ArgSettings::HideEnv)
}
/// Report whether [`Arg::hide_env_values`] is set
#[cfg(feature = "env")]
pub fn is_hide_env_values_set(&self) -> bool {
self.is_set(ArgSettings::HideEnvValues)
}
/// Report whether [`Arg::hide_short_help`] is set
pub fn is_hide_short_help_set(&self) -> bool {
self.is_set(ArgSettings::HiddenShortHelp)
}
/// Report whether [`Arg::hide_long_help`] is set
pub fn is_hide_long_help_set(&self) -> bool {
self.is_set(ArgSettings::HiddenLongHelp)
}
/// Report whether [`Arg::require_equals`] is set
pub fn is_require_equals_set(&self) -> bool {
self.is_set(ArgSettings::RequireEquals)
}
/// Reports whether [`Arg::exclusive`] is set
pub fn is_exclusive_set(&self) -> bool {
self.is_set(ArgSettings::Exclusive)
}
/// Report whether [`Arg::trailing_var_arg`] is set
pub fn is_trailing_var_arg_set(&self) -> bool {
self.is_set(ArgSettings::TrailingVarArg)
}
/// Reports whether [`Arg::last`] is set
pub fn is_last_set(&self) -> bool {
self.is_set(ArgSettings::Last)
}
/// Reports whether [`Arg::ignore_case`] is set
pub fn is_ignore_case_set(&self) -> bool {
self.is_set(ArgSettings::IgnoreCase)
}
/// Access an [`ArgExt`]
#[cfg(feature = "unstable-ext")]
pub fn get<T: ArgExt + Extension>(&self) -> Option<&T> {
self.ext.get::<T>()
}
/// Remove an [`ArgExt`]
#[cfg(feature = "unstable-ext")]
pub fn remove<T: ArgExt + Extension>(mut self) -> Option<T> {
self.ext.remove::<T>()
}
}
/// # Internally used only
impl Arg {
pub(crate) fn _build(&mut self) {
if self.action.is_none() {
if self.num_vals == Some(ValueRange::EMPTY) {
let action = ArgAction::SetTrue;
self.action = Some(action);
} else {
let action =
if self.is_positional() && self.num_vals.unwrap_or_default().is_unbounded() {
// Allow collecting arguments interleaved with flags
//
// Bounded values are probably a group and the user should explicitly opt-in to
// Append
ArgAction::Append
} else {
ArgAction::Set
};
self.action = Some(action);
}
}
if let Some(action) = self.action.as_ref() {
if let Some(default_value) = action.default_value() {
if self.default_vals.is_empty() {
self.default_vals = vec![default_value.into()];
}
}
if let Some(default_value) = action.default_missing_value() {
if self.default_missing_vals.is_empty() {
self.default_missing_vals = vec![default_value.into()];
}
}
}
if self.value_parser.is_none() {
if let Some(default) = self.action.as_ref().and_then(|a| a.default_value_parser()) {
self.value_parser = Some(default);
} else {
self.value_parser = Some(super::ValueParser::string());
}
}
let val_names_len = self.val_names.len();
if val_names_len > 1 {
self.num_vals.get_or_insert(val_names_len.into());
} else {
let nargs = if self.get_action().takes_values() {
ValueRange::SINGLE
} else {
ValueRange::EMPTY
};
self.num_vals.get_or_insert(nargs);
}
}
// Used for positionals when printing
pub(crate) fn name_no_brackets(&self) -> String {
debug!("Arg::name_no_brackets:{}", self.get_id());
let delim = " ";
if !self.val_names.is_empty() {
debug!("Arg::name_no_brackets: val_names={:#?}", self.val_names);
if self.val_names.len() > 1 {
self.val_names
.iter()
.map(|n| format!("<{n}>"))
.collect::<Vec<_>>()
.join(delim)
} else {
self.val_names
.first()
.expect(INTERNAL_ERROR_MSG)
.as_str()
.to_owned()
}
} else {
debug!("Arg::name_no_brackets: just name");
self.get_id().as_str().to_owned()
}
}
pub(crate) fn stylized(&self, styles: &Styles, required: Option<bool>) -> StyledStr {
use std::fmt::Write as _;
let literal = styles.get_literal();
let mut styled = StyledStr::new();
// Write the name such --long or -l
if let Some(l) = self.get_long() {
let _ = write!(
styled,
"{}--{l}{}",
literal.render(),
literal.render_reset()
);
} else if let Some(s) = self.get_short() {
let _ = write!(styled, "{}-{s}{}", literal.render(), literal.render_reset());
}
styled.push_styled(&self.stylize_arg_suffix(styles, required));
styled
}
pub(crate) fn stylize_arg_suffix(&self, styles: &Styles, required: Option<bool>) -> StyledStr {
use std::fmt::Write as _;
let literal = styles.get_literal();
let placeholder = styles.get_placeholder();
let mut styled = StyledStr::new();
let mut need_closing_bracket = false;
if self.is_takes_value_set() && !self.is_positional() {
let is_optional_val = self.get_min_vals() == 0;
let (style, start) = if self.is_require_equals_set() {
if is_optional_val {
need_closing_bracket = true;
(placeholder, "[=")
} else {
(literal, "=")
}
} else if is_optional_val {
need_closing_bracket = true;
(placeholder, " [")
} else {
(placeholder, " ")
};
let _ = write!(styled, "{}{start}{}", style.render(), style.render_reset());
}
if self.is_takes_value_set() || self.is_positional() {
let required = required.unwrap_or_else(|| self.is_required_set());
let arg_val = self.render_arg_val(required);
let _ = write!(
styled,
"{}{arg_val}{}",
placeholder.render(),
placeholder.render_reset()
);
} else if matches!(*self.get_action(), ArgAction::Count) {
let _ = write!(
styled,
"{}...{}",
placeholder.render(),
placeholder.render_reset()
);
}
if need_closing_bracket {
let _ = write!(
styled,
"{}]{}",
placeholder.render(),
placeholder.render_reset()
);
}
styled
}
/// Write the values such as `<name1> <name2>`
fn render_arg_val(&self, required: bool) -> String {
let mut rendered = String::new();
let num_vals = self.get_num_args().unwrap_or_else(|| 1.into());
let mut val_names = if self.val_names.is_empty() {
vec![self.id.as_internal_str().to_owned()]
} else {
self.val_names.clone()
};
if val_names.len() == 1 {
let min = num_vals.min_values().max(1);
let val_name = val_names.pop().unwrap();
val_names = vec![val_name; min];
}
debug_assert!(self.is_takes_value_set());
for (n, val_name) in val_names.iter().enumerate() {
let arg_name = if self.is_positional() && (num_vals.min_values() == 0 || !required) {
format!("[{val_name}]")
} else {
format!("<{val_name}>")
};
if n != 0 {
rendered.push(' ');
}
rendered.push_str(&arg_name);
}
let mut extra_values = false;
extra_values |= val_names.len() < num_vals.max_values();
if self.is_positional() && matches!(*self.get_action(), ArgAction::Append) {
extra_values = true;
}
if extra_values {
rendered.push_str("...");
}
rendered
}
/// Either multiple values or occurrences
pub(crate) fn is_multiple(&self) -> bool {
self.is_multiple_values_set() || matches!(*self.get_action(), ArgAction::Append)
}
#[cfg(feature = "help")]
pub(crate) fn get_display_order(&self) -> usize {
self.disp_ord.unwrap_or(999)
}
}
impl From<&'_ Arg> for Arg {
fn from(a: &Arg) -> Self {
a.clone()
}
}
impl PartialEq for Arg {
fn eq(&self, other: &Arg) -> bool {
self.get_id() == other.get_id()
}
}
impl PartialOrd for Arg {
fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
Some(self.cmp(other))
}
}
impl Ord for Arg {
fn cmp(&self, other: &Arg) -> Ordering {
self.get_id().cmp(other.get_id())
}
}
impl Eq for Arg {}
impl Display for Arg {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
let plain = Styles::plain();
self.stylized(&plain, None).fmt(f)
}
}
impl fmt::Debug for Arg {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> {
let mut ds = f.debug_struct("Arg");
#[allow(unused_mut)]
let mut ds = ds
.field("id", &self.id)
.field("help", &self.help)
.field("long_help", &self.long_help)
.field("action", &self.action)
.field("value_parser", &self.value_parser)
.field("blacklist", &self.blacklist)
.field("settings", &self.settings)
.field("overrides", &self.overrides)
.field("groups", &self.groups)
.field("requires", &self.requires)
.field("r_ifs", &self.r_ifs)
.field("r_unless", &self.r_unless)
.field("short", &self.short)
.field("long", &self.long)
.field("aliases", &self.aliases)
.field("short_aliases", &self.short_aliases)
.field("disp_ord", &self.disp_ord)
.field("val_names", &self.val_names)
.field("num_vals", &self.num_vals)
.field("val_delim", &self.val_delim)
.field("default_vals", &self.default_vals)
.field("default_vals_ifs", &self.default_vals_ifs)
.field("terminator", &self.terminator)
.field("index", &self.index)
.field("help_heading", &self.help_heading)
.field("default_missing_vals", &self.default_missing_vals)
.field("ext", &self.ext);
#[cfg(feature = "env")]
{
ds = ds.field("env", &self.env);
}
ds.finish()
}
}
/// User-provided data that can be attached to an [`Arg`]
#[cfg(feature = "unstable-ext")]
pub trait ArgExt: Extension {}
// Flags
#[cfg(test)]
mod test {
use super::Arg;
use super::ArgAction;
#[test]
fn flag_display_long() {
let mut f = Arg::new("flg").long("flag").action(ArgAction::SetTrue);
f._build();
assert_eq!(f.to_string(), "--flag");
}
#[test]
fn flag_display_short() {
let mut f2 = Arg::new("flg").short('f').action(ArgAction::SetTrue);
f2._build();
assert_eq!(f2.to_string(), "-f");
}
#[test]
fn flag_display_count() {
let mut f2 = Arg::new("flg").long("flag").action(ArgAction::Count);
f2._build();
assert_eq!(f2.to_string(), "--flag...");
}
#[test]
fn flag_display_single_alias() {
let mut f = Arg::new("flg")
.long("flag")
.visible_alias("als")
.action(ArgAction::SetTrue);
f._build();
assert_eq!(f.to_string(), "--flag");
}
#[test]
fn flag_display_multiple_aliases() {
let mut f = Arg::new("flg").short('f').action(ArgAction::SetTrue);
f.aliases = vec![
("alias_not_visible".into(), false),
("f2".into(), true),
("f3".into(), true),
("f4".into(), true),
];
f._build();
assert_eq!(f.to_string(), "-f");
}
#[test]
fn flag_display_single_short_alias() {
let mut f = Arg::new("flg").short('a').action(ArgAction::SetTrue);
f.short_aliases = vec![('b', true)];
f._build();
assert_eq!(f.to_string(), "-a");
}
#[test]
fn flag_display_multiple_short_aliases() {
let mut f = Arg::new("flg").short('a').action(ArgAction::SetTrue);
f.short_aliases = vec![('b', false), ('c', true), ('d', true), ('e', true)];
f._build();
assert_eq!(f.to_string(), "-a");
}
// Options
#[test]
fn option_display_multiple_occurrences() {
let mut o = Arg::new("opt").long("option").action(ArgAction::Append);
o._build();
assert_eq!(o.to_string(), "--option <opt>");
}
#[test]
fn option_display_multiple_values() {
let mut o = Arg::new("opt")
.long("option")
.action(ArgAction::Set)
.num_args(1..);
o._build();
assert_eq!(o.to_string(), "--option <opt>...");
}
#[test]
fn option_display_zero_or_more_values() {
let mut o = Arg::new("opt")
.long("option")
.action(ArgAction::Set)
.num_args(0..);
o._build();
assert_eq!(o.to_string(), "--option [<opt>...]");
}
#[test]
fn option_display_one_or_more_values() {
let mut o = Arg::new("opt")
.long("option")
.action(ArgAction::Set)
.num_args(1..);
o._build();
assert_eq!(o.to_string(), "--option <opt>...");
}
#[test]
fn option_display_zero_or_more_values_with_value_name() {
let mut o = Arg::new("opt")
.short('o')
.action(ArgAction::Set)
.num_args(0..)
.value_names(["file"]);
o._build();
assert_eq!(o.to_string(), "-o [<file>...]");
}
#[test]
fn option_display_one_or_more_values_with_value_name() {
let mut o = Arg::new("opt")
.short('o')
.action(ArgAction::Set)
.num_args(1..)
.value_names(["file"]);
o._build();
assert_eq!(o.to_string(), "-o <file>...");
}
#[test]
fn option_display_optional_value() {
let mut o = Arg::new("opt")
.long("option")
.action(ArgAction::Set)
.num_args(0..=1);
o._build();
assert_eq!(o.to_string(), "--option [<opt>]");
}
#[test]
fn option_display_value_names() {
let mut o = Arg::new("opt")
.short('o')
.action(ArgAction::Set)
.value_names(["file", "name"]);
o._build();
assert_eq!(o.to_string(), "-o <file> <name>");
}
#[test]
fn option_display3() {
let mut o = Arg::new("opt")
.short('o')
.num_args(1..)
.action(ArgAction::Set)
.value_names(["file", "name"]);
o._build();
assert_eq!(o.to_string(), "-o <file> <name>...");
}
#[test]
fn option_display_single_alias() {
let mut o = Arg::new("opt")
.long("option")
.action(ArgAction::Set)
.visible_alias("als");
o._build();
assert_eq!(o.to_string(), "--option <opt>");
}
#[test]
fn option_display_multiple_aliases() {
let mut o = Arg::new("opt")
.long("option")
.action(ArgAction::Set)
.visible_aliases(["als2", "als3", "als4"])
.alias("als_not_visible");
o._build();
assert_eq!(o.to_string(), "--option <opt>");
}
#[test]
fn option_display_single_short_alias() {
let mut o = Arg::new("opt")
.short('a')
.action(ArgAction::Set)
.visible_short_alias('b');
o._build();
assert_eq!(o.to_string(), "-a <opt>");
}
#[test]
fn option_display_multiple_short_aliases() {
let mut o = Arg::new("opt")
.short('a')
.action(ArgAction::Set)
.visible_short_aliases(['b', 'c', 'd'])
.short_alias('e');
o._build();
assert_eq!(o.to_string(), "-a <opt>");
}
// Positionals
#[test]
fn positional_display_multiple_values() {
let mut p = Arg::new("pos").index(1).num_args(1..);
p._build();
assert_eq!(p.to_string(), "[pos]...");
}
#[test]
fn positional_display_multiple_values_required() {
let mut p = Arg::new("pos").index(1).num_args(1..).required(true);
p._build();
assert_eq!(p.to_string(), "<pos>...");
}
#[test]
fn positional_display_zero_or_more_values() {
let mut p = Arg::new("pos").index(1).num_args(0..);
p._build();
assert_eq!(p.to_string(), "[pos]...");
}
#[test]
fn positional_display_one_or_more_values() {
let mut p = Arg::new("pos").index(1).num_args(1..);
p._build();
assert_eq!(p.to_string(), "[pos]...");
}
#[test]
fn positional_display_one_or_more_values_required() {
let mut p = Arg::new("pos").index(1).num_args(1..).required(true);
p._build();
assert_eq!(p.to_string(), "<pos>...");
}
#[test]
fn positional_display_optional_value() {
let mut p = Arg::new("pos")
.index(1)
.num_args(0..=1)
.action(ArgAction::Set);
p._build();
assert_eq!(p.to_string(), "[pos]");
}
#[test]
fn positional_display_multiple_occurrences() {
let mut p = Arg::new("pos").index(1).action(ArgAction::Append);
p._build();
assert_eq!(p.to_string(), "[pos]...");
}
#[test]
fn positional_display_multiple_occurrences_required() {
let mut p = Arg::new("pos")
.index(1)
.action(ArgAction::Append)
.required(true);
p._build();
assert_eq!(p.to_string(), "<pos>...");
}
#[test]
fn positional_display_required() {
let mut p = Arg::new("pos").index(1).required(true);
p._build();
assert_eq!(p.to_string(), "<pos>");
}
#[test]
fn positional_display_val_names() {
let mut p = Arg::new("pos").index(1).value_names(["file1", "file2"]);
p._build();
assert_eq!(p.to_string(), "[file1] [file2]");
}
#[test]
fn positional_display_val_names_required() {
let mut p = Arg::new("pos")
.index(1)
.value_names(["file1", "file2"])
.required(true);
p._build();
assert_eq!(p.to_string(), "<file1> <file2>");
}
}