Enum `ValueHint`

#[non_exhaustive]
pub enum ValueHint

Provide shell with hint on how to complete an argument.

See [Arg::value_hint][crate::Arg::value_hint] to set this on an argument.

See the clap_complete crate for completion script generation.

Overview of which hints are supported by which shell:

Hint	zsh	fish¹	dynamic
`AnyPath`	Yes	Yes	Yes
`FilePath`	Yes	Yes	Yes
`DirPath`	Yes	Yes	Yes
`ExecutablePath`	Yes	Partial	Yes
`CommandName`	Yes	Yes	No
`CommandString`	Yes	Partial	No
`CommandWithArguments`	Yes		No
`Username`	Yes	Yes	No
`Hostname`	Yes	Yes	No
`Url`	Yes		No
`EmailAddress`	Yes		No

fish completions currently only support named arguments (e.g. -o or --opt), not positional arguments. ↩

Variants

Unknown

Default value if hint is not specified. Follows shell default behavior, which is usually auto-completing filenames.

Other

None of the hints below apply. Disables shell completion for this argument.

AnyPath

Any existing path.

FilePath

Path to a file.

DirPath

Path to a directory.

ExecutablePath

Path to an executable file.

CommandName

Name of a command, without arguments. May be relative to PATH, or full path to executable.

CommandString

A single string containing a command and its arguments.

CommandWithArguments

Capture the remaining arguments as a command name and arguments for that command. This is common when writing shell wrappers that execute another command, for example sudo or env.

This hint is special, the argument must be a positional argument and have .num_args(1..) and Command must use Command::trailing_var_arg(true). The result is that the command line my_app ls -la / will be parsed as ["ls", "-la", "/"] and clap won't try to parse the -la argument itself.

Username

Name of a local operating system user.

Hostname

Host name of a computer. Shells usually parse /etc/hosts and .ssh/known_hosts to complete hostnames.

Url

Complete web address.

EmailAddress

Email address.

Trait Implementations

`impl Clone for ValueHint`

fn clone(&self) -> ValueHint

`impl Copy for ValueHint`

`impl Debug for ValueHint`

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

`impl Default for ValueHint`

fn default() -> ValueHint

`impl Eq for ValueHint`

`impl FromStr for ValueHint`

type Err = String;
fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err>

`impl Hash for ValueHint`

fn hash<__H: Hasher>(&self, state: &mut __H)

`impl IntoResettable<ValueHint> for ValueHint`

fn into_resettable(self) -> Resettable<ValueHint>

`impl PartialEq for ValueHint`

fn eq(&self, other: &ValueHint) -> bool

`impl StructuralPartialEq for ValueHint`

Auto Trait Implementations

`impl Freeze for ValueHint`

`impl RefUnwindSafe for ValueHint`

`impl Send for ValueHint`

`impl Sync for ValueHint`

`impl Unpin for ValueHint`

`impl UnsafeUnpin for ValueHint`

`impl UnwindSafe for ValueHint`

Blanket Implementations

`impl<T> Any for ValueHint where T: 'static + ?Sized,`

fn type_id(&self) -> TypeId

`impl<T> Borrow<T> for ValueHint where T: ?Sized,`

fn borrow(&self) -> &T

`impl<T> BorrowMut<T> for ValueHint where T: ?Sized,`

fn borrow_mut(&mut self) -> &mut T

`impl<T> CloneToUninit for ValueHint where T: Clone,`

unsafe fn clone_to_uninit(&self, dest: *mut u8)

`impl<T> From<T> for ValueHint`

fn from(t: T) -> T: Returns the argument unchanged.

`impl<T> ToOwned for ValueHint where T: Clone,`

type Owned = T;
fn to_owned(&self) -> T
fn clone_into(&self, target: &mut T)

`impl<T, U> Into<U> for ValueHint where U: From<T>,`

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

`impl<T, U> TryFrom<U> for ValueHint where U: Into<T>,`

type Error = Infallible;
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

`impl<T, U> TryInto<U> for ValueHint where U: TryFrom<T>,`

type Error = <U as TryFrom<T>>::Error;
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>