rustix/io/errno.rs
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//! The `Errno` type, which is a minimal wrapper around an error code.
//!
//! We define the error constants as individual `const`s instead of an enum
//! because we may not know about all of the host's error values and we don't
//! want unrecognized values to create undefined behavior.
use crate::backend;
use core::{fmt, result};
#[cfg(feature = "std")]
use std::error;
/// A specialized [`Result`] type for `rustix` APIs.
pub type Result<T> = result::Result<T, Errno>;
/// `errno`—An error code.
///
/// The error type for `rustix` APIs. This is similar to [`std::io::Error`],
/// but only holds an OS error code, and no extra error value.
///
/// # References
/// - [POSIX]
/// - [Linux]
/// - [Winsock2]
/// - [FreeBSD]
/// - [NetBSD]
/// - [OpenBSD]
/// - [DragonFly BSD]
/// - [illumos]
/// - [glibc]
///
/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/errno.html
/// [Linux]: https://man7.org/linux/man-pages/man3/errno.3.html
/// [Winsock2]: https://learn.microsoft.com/en-us/windows/win32/winsock/windows-sockets-error-codes-2
/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?errno
/// [NetBSD]: https://man.netbsd.org/errno.2
/// [OpenBSD]: https://man.openbsd.org/errno.2
/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=errno§ion=2
/// [illumos]: https://illumos.org/man/3C/errno
/// [glibc]: https://www.gnu.org/software/libc/manual/html_node/Error-Codes.html
pub use backend::io::errno::Errno;
impl Errno {
/// Shorthand for `std::io::Error::from(self).kind()`.
#[cfg(feature = "std")]
#[inline]
pub fn kind(self) -> std::io::ErrorKind {
std::io::Error::from(self).kind()
}
}
impl fmt::Display for Errno {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
#[cfg(feature = "std")]
{
std::io::Error::from(*self).fmt(fmt)
}
#[cfg(not(feature = "std"))]
{
write!(fmt, "os error {}", self.raw_os_error())
}
}
}
impl fmt::Debug for Errno {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
#[cfg(feature = "std")]
{
std::io::Error::from(*self).fmt(fmt)
}
#[cfg(not(feature = "std"))]
{
write!(fmt, "os error {}", self.raw_os_error())
}
}
}
#[cfg(feature = "std")]
impl error::Error for Errno {}
#[cfg(feature = "std")]
impl From<Errno> for std::io::Error {
#[inline]
fn from(err: Errno) -> Self {
Self::from_raw_os_error(err.raw_os_error() as _)
}
}
/// Call `f` until it either succeeds or fails other than [`Errno::INTR`].
#[inline]
pub fn retry_on_intr<T, F: FnMut() -> Result<T>>(mut f: F) -> Result<T> {
loop {
match f() {
Err(Errno::INTR) => (),
result => return result,
}
}
}