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Diffstat (limited to 'vendor/rustix/src/io/dup.rs')
| -rw-r--r-- | vendor/rustix/src/io/dup.rs | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/vendor/rustix/src/io/dup.rs b/vendor/rustix/src/io/dup.rs new file mode 100644 index 000000000..ffa0401f2 --- /dev/null +++ b/vendor/rustix/src/io/dup.rs @@ -0,0 +1,80 @@ +//! Functions which duplicate file descriptors. + +use crate::imp; +use crate::io::{self, OwnedFd}; +use imp::fd::AsFd; + +#[cfg(not(target_os = "wasi"))] +pub use imp::io::types::DupFlags; + +/// `dup(fd)`—Creates a new `OwnedFd` instance that shares the same +/// underlying [file description] as `fd`. +/// +/// This function does not set the `O_CLOEXEC` flag. To do a `dup` that does +/// set `O_CLOEXEC`, use [`fcntl_dupfd_cloexec`]. +/// +/// POSIX guarantees that `dup` will use the lowest unused file descriptor, +/// however it is not safe in general to rely on this, as file descriptors may +/// be unexpectedly allocated on other threads or in libraries. +/// +/// # References +/// - [POSIX] +/// - [Linux] +/// - [Apple] +/// +/// [file description]: https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_258 +/// [`fcntl_dupfd_cloexec`]: crate::fs::fcntl_dupfd_cloexec +/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/dup.html +/// [Linux]: https://man7.org/linux/man-pages/man2/dup.2.html +/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/dup.2.html +#[cfg(not(target_os = "wasi"))] +#[inline] +pub fn dup<Fd: AsFd>(fd: Fd) -> io::Result<OwnedFd> { + imp::io::syscalls::dup(fd.as_fd()) +} + +/// `dup2(fd, new)`—Changes the [file description] of a file descriptor. +/// +/// `dup2` conceptually closes `new` and then sets the file description for +/// `new` to be the same as the one for `fd`. This is a very unusual operation, +/// and should only be used on file descriptors where you know how `new` will +/// be subsequently used. +/// +/// This function does not set the `O_CLOEXEC` flag. To do a `dup2` that does +/// set `O_CLOEXEC`, use [`dup3`] with [`DupFlags::CLOEXEC`] on platforms which +/// support it, or [`fcntl_dupfd_cloexec`] +/// +/// # References +/// - [POSIX] +/// - [Linux] +/// - [Apple] +/// +/// [file description]: https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_258 +/// [`fcntl_dupfd_cloexec`]: crate::fs::fcntl_dupfd_cloexec +/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/dup2.html +/// [Linux]: https://man7.org/linux/man-pages/man2/dup2.2.html +/// [Apple]: https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man2/dup2.2.html +#[cfg(not(target_os = "wasi"))] +#[inline] +pub fn dup2<Fd: AsFd>(fd: Fd, new: &mut OwnedFd) -> io::Result<()> { + imp::io::syscalls::dup2(fd.as_fd(), new) +} + +/// `dup3(fd, new, flags)`—Changes the [file description] of a file +/// descriptor, with flags. +/// +/// `dup3` is the same as [`dup2`] but adds an additional flags operand, and it +/// fails in the case that `fd` and `new` have the same file descriptor value. +/// This additional difference is the reason this function isn't named +/// `dup2_with`. +/// +/// # References +/// - [Linux] +/// +/// [file description]: https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_258 +/// [Linux]: https://man7.org/linux/man-pages/man2/dup3.2.html +#[cfg(not(target_os = "wasi"))] +#[inline] +pub fn dup3<Fd: AsFd>(fd: Fd, new: &mut OwnedFd, flags: DupFlags) -> io::Result<()> { + imp::io::syscalls::dup3(fd.as_fd(), new, flags) +} |