1 //! The unsafe `close` for raw file descriptors.
2 //!
3 //! # Safety
4 //!
5 //! Operating on raw file descriptors is unsafe.
6 #![allow(unsafe_code)]
7 
8 use crate::backend;
9 use backend::fd::RawFd;
10 
11 /// `close(raw_fd)`—Closes a `RawFd` directly.
12 ///
13 /// Most users won't need to use this, as `OwnedFd` automatically closes its
14 /// file descriptor on `Drop`.
15 ///
16 /// This function does not return a `Result`, as it is the [responsibility] of
17 /// filesystem designers to not return errors from `close`. Users who chose to
18 /// use NFS or similar filesystems should take care to monitor for problems
19 /// externally.
20 ///
21 /// [responsibility]: https://lwn.net/Articles/576518/
22 ///
23 /// # References
24 ///  - [Beej's Guide to Network Programming]
25 ///  - [POSIX]
26 ///  - [Linux]
27 ///  - [Apple]
28 ///  - [Winsock]
29 ///  - [FreeBSD]
30 ///  - [NetBSD]
31 ///  - [OpenBSD]
32 ///  - [DragonFly BSD]
33 ///  - [illumos]
34 ///  - [glibc]
35 ///
36 /// [Beej's Guide to Network Programming]: https://beej.us/guide/bgnet/html/split/system-calls-or-bust.html#close-and-shutdownget-outta-my-face
37 /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html
38 /// [Linux]: https://man7.org/linux/man-pages/man2/close.2.html
39 /// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/close.2.html#//apple_ref/doc/man/2/close
40 /// [Winsock]: https://docs.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-closesocket
41 /// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?query=close&sektion=2
42 /// [NetBSD]: https://man.netbsd.org/close.2
43 /// [OpenBSD]: https://man.openbsd.org/close.2
44 /// [DragonFly BSD]: https://man.dragonflybsd.org/?command=close&section=2
45 /// [illumos]: https://illumos.org/man/2/close
46 /// [glibc]: https://www.gnu.org/software/libc/manual/html_node/Opening-and-Closing-Files.html#index-close
47 ///
48 /// # Safety
49 ///
50 /// This function takes a `RawFd`, which must be valid before the call, and is
51 /// not valid after the call.
52 #[inline]
close(raw_fd: RawFd)53 pub unsafe fn close(raw_fd: RawFd) {
54     backend::io::syscalls::close(raw_fd)
55 }
56