Enum bash_builtins::Error

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pub enum Error {
    Usage,
    ExitCode(c_int),
    GenericError(Box<dyn Error>),
}
Expand description

The error type for Builtin::call.

Usually, you don’t need to construct this type manually. Instead, use the ? operator for any Result in the body of the Builtin::call method, and errors will be converted to this type.

However, if you want to return a specific exit code, use the ExitCode variant.

Variants§

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Usage

Syntax error in usage.

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ExitCode(c_int)

Exit with a specific code.

§Example

use bash_builtins::{Args, Builtin, Error::ExitCode, Result};

impl Builtin for SomeName {
    fn call(&mut self, args: &mut Args) -> Result<()> {
        // In this builtin, we return `127` if there are
        // no arguments.
        if args.is_empty() {
            return Err(ExitCode(127));
        }

        // …

        Ok(())
    }
}
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GenericError(Box<dyn Error>)

Wrapper for any error.

This variant is used when the builtin propagates any error inside Builtin::call.

§Example

use std::fs;
use bash_builtins::{Args, Builtin, Error::ExitCode, Result};

impl Builtin for SomeName {
    fn call(&mut self, args: &mut Args) -> Result<()> {

        // fs::read can return an `io::Error`, which is wrapped
        // by `GenericError` and then used as the return value.
        let _ = fs::read("/some/config/file")?;

        // …

        Ok(())
    }
}

Trait Implementations§

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impl Debug for Error

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

Formats the value using the given formatter. Read more
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impl Display for Error

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

Formats the value using the given formatter. Read more
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impl<E> From<E> for Error
where E: Error + 'static,

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fn from(error: E) -> Self

Converts to this type from the input type.

Auto Trait Implementations§

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impl Freeze for Error

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impl !RefUnwindSafe for Error

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impl !Send for Error

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impl !Sync for Error

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impl Unpin for Error

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impl !UnwindSafe for Error

Blanket Implementations§

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

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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

Mutably borrows from an owned value. Read more
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impl<T> From<!> for T

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fn from(t: !) -> T

Converts to this type from the input type.
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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

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fn into(self) -> U

Calls U::from(self).

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

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impl<T> ToString for T
where T: Display + ?Sized,

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default fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.