filedesc

This crate exposes a single type: FileDesc, which acts as a thin wrapper around open file descriptors. The wrapped file descriptor is closed when the wrapper is dropped.

You can call FileDesc::new() with any type that implements IntoRawFd, or duplicate the file descriptor of a type that implements AsRawFd with duplicate_from, or directly from a raw file descriptor with from_raw_fd() and duplicate_raw_fd(). Wrapped file descriptors can also be duplicated with the duplicate() function.

Note that duplicating file descriptors is always unsafe, even if it is known to be a valid file descriptor. This is because the new file descriptor still shares ownership of the underlying kernel object with the original file descriptor. This could violate the assumptions of otherwise safe APIs, which in turn would lead to unsound programs.

Close-on-exec

Whenever the library duplicates a file descriptor, it tries to set the close-on-exec flag atomically. On platforms where this is not supported, the library falls back to setting the flag non-atomically. When an existing file descriptor is wrapped, the close-on-exec flag is left as it was.

You can also check or set the close-on-exec flag with the get_close_on_exec() and set_close_on_exec functions.

Example

```rust use filedesc::FileDesc; let fd = unsafe { FileDesc::fromrawfd(rawfd) }; let duplicated = unsafe { fd.duplicate()? }; asserteq!(duplicated.getcloseon_exec()?, true);

duplicated.setcloseonexec(false)?; asserteq!(duplicated.getcloseon_exec()?, false); ```