# libc - Raw FFI bindings to platforms' system libraries
[![GHA Status]][GitHub Actions] [![Cirrus CI Status]][Cirrus CI] [![Latest Version]][crates.io] [![Documentation]][docs.rs] ![License]
`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][rfc].
[rfc]: https://github.com/rust-lang/rfcs/blob/HEAD/text/1291-promote-libc.md
[windows-sys]: https://docs.rs/windows-sys
## v0.3 Roadmap
The main branch is now for v0.3 which has some breaking changes.
For v0.2, please submit PRs to the `libc-0.2` branch instead. We will stop
making new v0.2 releases once we release v0.3 on crates.io.
See the [tracking issue](https://github.com/rust-lang/libc/issues/3248) for
details.
## Usage
Add the following to your `Cargo.toml`:
```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 `struct`s implemented in `libc` are `Copy` and `Clone`.
This feature derives `Debug`, `Eq`, `Hash`, and `PartialEq`.
* `const-extern-fn`: Changes some `extern fn`s into `const extern fn`s. If you
use Rust >= 1.62, this feature is implicitly enabled. Otherwise it requires a
nightly rustc.
* **deprecated**: `use_std` is deprecated, and is equivalent to `std`.
## Rust version support
The minimum supported Rust toolchain version is currently **Rust 1.13.0**. (libc
does not currently have any policy regarding changes to the minimum supported
Rust version; such policy is a work in progress.) APIs requiring newer Rust
features are only available on newer Rust toolchains:
| `union` | 1.19.0 |
| `const mem::size_of` | 1.24.0 |
| `repr(align)` | 1.25.0 |
| `extra_traits` | 1.25.0 |
| `core::ffi::c_void` | 1.30.0 |
| `repr(packed(N))` | 1.33.0 |
| `cfg(target_vendor)` | 1.33.0 |
| `const-extern-fn` | 1.62.0 |
## Platform support
You can see the platform(target)-specific docs on [docs.rs], select a platform
you want to see.
See [`ci/build.sh`](https://github.com/rust-lang/libc/blob/HEAD/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.
<div class="platform_docs"></div>
## License
This project is licensed under either of
* [Apache License, Version 2.0](https://www.apache.org/licenses/LICENSE-2.0)
([LICENSE-APACHE](https://github.com/rust-lang/libc/blob/HEAD/LICENSE-APACHE))
* [MIT License](https://opensource.org/licenses/MIT)
([LICENSE-MIT](https://github.com/rust-lang/libc/blob/HEAD/LICENSE-MIT))
at your option.
## Contributing
We welcome all people who want to contribute. Please see the
[contributing instructions] for more information.
[contributing instructions]: https://github.com/rust-lang/libc/blob/HEAD/CONTRIBUTING.md
Contributions in any form (issues, pull requests, etc.) to this project must
adhere to Rust's [Code of Conduct].
[Code of Conduct]: https://www.rust-lang.org/policies/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.
[GitHub Actions]: https://github.com/rust-lang/libc/actions
[GHA Status]: https://github.com/rust-lang/libc/workflows/CI/badge.svg
[Cirrus CI]: https://cirrus-ci.com/github/rust-lang/libc
[Cirrus CI Status]: https://api.cirrus-ci.com/github/rust-lang/libc.svg
[crates.io]: https://crates.io/crates/libc
[Latest Version]: https://img.shields.io/crates/v/libc.svg
[Documentation]: https://docs.rs/libc/badge.svg
[docs.rs]: https://docs.rs/libc
[License]: https://img.shields.io/crates/l/libc.svg