Trait std::os::wasi::io::FromRawFd

1.1.0· source · [−]

pub trait FromRawFd {
    unsafe fn from_raw_fd(fd: RawFd) -> Self;
}

This is supported on WASI only.

Expand description

A trait to express the ability to construct an object from a raw file descriptor.

Required methods

source

unsafe fn from_raw_fd(fd: RawFd) -> Self

Constructs a new instance of Self from the given raw file descriptor.

This function consumes ownership of the specified file descriptor. The returned object will take responsibility for closing it when the object goes out of scope.

This function is also unsafe as the primitives currently returned have the contract that they are the sole owner of the file descriptor they are wrapping. Usage of this function could accidentally allow violating this contract which can cause memory unsafety in code that relies on it being true.

Example

use std::fs::File;
#[cfg(unix)]
use std::os::unix::io::{FromRawFd, IntoRawFd, RawFd};
#[cfg(target_os = "wasi")]
use std::os::wasi::io::{FromRawFd, IntoRawFd, RawFd};

let f = File::open("foo.txt")?;
let raw_fd: RawFd = f.into_raw_fd();
// SAFETY: no other functions should call `from_raw_fd`, so there
// is only one owner for the file descriptor.
let f = unsafe { File::from_raw_fd(raw_fd) };