libc - Raw FFI bindings to platforms' system libraries

libc provides all of the definitions necessary to easily interoperate with C code (or "C-like" code) on each of the platforms that Rust supports. This includes type definitions (e.g. c_int), constants (e.g. EINVAL) as well as function headers (e.g. malloc).

This crate exports all underlying platform types, functions, and constants under the crate root, so all items are accessible as libc::foo. The types and values of all the exported APIs match the platform that libc is compiled for.

Windows API bindings are not included in this crate. If you are looking for WinAPI bindings, consider using crates like windows-sys.

More detailed information about the design of this library can be found in its associated RFC.

v1.0 Roadmap

Currently, libc has two active branches: main for the upcoming v1.0 release, and libc-0.2 for the currently published version. By default all pull requests should target main; once reviewed, they can be cherry picked to the libc-0.2 branch if needed.

We will stop making new v0.2 releases once v1.0 is released.

See the section in CONTRIBUTING.md for more details.

Usage

Add the following to your Cargo.toml:

[dependencies]
libc = "0.2"

Features

std: by default libc links to the standard library. Disable this feature to remove this dependency and be able to use libc in #![no_std] crates.
extra_traits: all structs implemented in libc are Copy and Clone. This feature derives Debug, Eq, Hash, and PartialEq.
const-extern-fn: Changes some extern fns into const extern fns. If you use Rust >= 1.62, this feature is implicitly enabled. Otherwise it requires a nightly rustc.

Rust version support

The minimum supported Rust toolchain version is currently Rust 1.63.

Increases to the MSRV are allowed to change without a major (i.e. semver- breaking) release in order to avoid a ripple effect in the ecosystem. A policy for when this may change is a work in progress.

libc may continue to compile with Rust versions older than the current MSRV but this is not guaranteed.

Platform support

You can see the platform(target)-specific docs on docs.rs, select a platform you want to see.

See ci/build.sh for the platforms on which libc is guaranteed to build for each Rust toolchain. The test-matrix at GitHub Actions and Cirrus CI show the platforms in which libc tests are run.

License

This project is licensed under either of

at your option.

Contributing

We welcome all people who want to contribute. Please see the contributing instructions for more information.

Contributions in any form (issues, pull requests, etc.) to this project must adhere to Rust's Code of Conduct.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in libc by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

rust-lang/libc