unix - How can I read from a specific raw file descriptor in Rust?

Question

Editor's note: This question is for a version of Rust prior to 1.0. Some answers have been updated to cover Rust 1.0 or up, but not all.

I am writing a systemd socket activated service in Rust. My process is being handed an open file descriptor by systemd.

Are there any Rust IO functions that take a raw file descriptor?

I'm using a Rust nightly before Rust 1.0.

Answer 1

I think right now your best bet is probably using the libc crate for working with raw file descriptors.

The movement of FileDesc to private scope was fallout from the runtime removal a few months back. See this RFC for some more context. std::os::unix currently has the type Fd, and I believe the long term idea is to expose more of the platform-specific functionality in that module.