Struct system_error::Error

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pub struct Error(/* private fields */);

Expand description

An error type for cross platform system-level errors.

This type captures the behavior and error message for errno on unix platforms, GetLastError() on Windows, and kern_return_t on macOS and iOS.

Implementations§

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impl Error

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pub fn last_os_error() -> Self

Returns an error representing the last OS error which occurred.

This function reads the value of errno for the target platform (e.g. GetLastError on Windows) and will return a corresponding instance of Error for the error code.

§Examples

use system_error::Error;

println!("last OS error: {:?}", Error::last_os_error());

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pub fn from_raw_os_error(code: OsCode) -> Self

Creates a new instance of an Error from a particular OS error code.

§Examples

On Linux:

use system_error::Error;
use std::io;

let error = Error::from_raw_os_error(22);
assert_eq!(error.kind(), io::ErrorKind::InvalidInput);

On Windows:

use system_error::Error;
use std::io;

let error = Error::from_raw_os_error(10022);
assert_eq!(error.kind(), io::ErrorKind::InvalidInput);

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pub fn from_raw_kernel_error(code: KernelCode) -> Self

Creates a new instance of an Error from a particular kernel error code.

§Examples

On macOS:

use system_error::Error;
use std::io;

let error = Error::from_raw_kernel_error(4);
assert_eq!(error.kind(), io::ErrorKind::InvalidInput);

On Linux:

use system_error::Error;
use std::io;

let error = Error::from_raw_kernel_error(4);
assert_eq!(error.kind(), io::ErrorKind::Other);

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pub fn kind(&self) -> ErrorKind

Returns the corresponding ErrorKind for this error.

§Examples

use system_error::Error;
use std::io;

assert_eq!(Error::from_raw_os_error(1).kind(), io::ErrorKind::PermissionDenied);

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pub fn raw_os_error(&self) -> Option<i32>

Returns the OS error that this error represents (if any).

If this Error was constructed via last_os_error or from_raw_os_error, then this function will return Some, otherwise it will return None.

§Examples

use system_error::Error;

fn print_os_error(err: &Error) {
    if let Some(raw_os_err) = err.raw_os_error() {
        println!("raw OS error: {:?}", raw_os_err);
    } else {
        println!("Not an OS error");
    }
}

let os_err = Error::last_os_error();
let kern_err = Error::from_raw_kernel_error(8);

// Will print "raw OS error: ...".
print_os_error(&os_err);
// Will print "Not an OS error".
print_os_error(&kern_err);

assert!(os_err.raw_os_error().is_some());
assert_eq!(kern_err.raw_os_error(), None);

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pub fn raw_kernel_error(&self) -> Option<i32>

Returns the kernel error that this error represents (if any).

If this Error was constructed via from_raw_kernel_error then this function will return Some, otherwise it will return None.

§Examples

use system_error::Error;

fn print_kernel_error(err: &Error) {
    if let Some(raw_kernel_err) = err.raw_kernel_error() {
        println!("raw kernel error: {:?}", raw_kernel_err);
    } else {
        println!("Not an kernel error");
    }
}

let kern_err = Error::from_raw_kernel_error(8);
let os_err = Error::last_os_error();

// Will print "raw kernel error: 8".
print_kernel_error(&kern_err);
// Will print "Not an kernel error".
print_kernel_error(&os_err);

assert_eq!(kern_err.raw_kernel_error(), Some(8));
assert_eq!(os_err.raw_kernel_error(), None);