1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
|
<div align="center">
<h1><code>rustix</code></h1>
<p>
<strong>Safe Rust bindings to POSIX/Unix/Linux/Winsock2 syscalls</strong>
</p>
<strong>A <a href="https://bytecodealliance.org/">Bytecode Alliance</a> project</strong>
<p>
<a href="https://github.com/bytecodealliance/rustix/actions?query=workflow%3ACI"><img src="https://github.com/bytecodealliance/rustix/workflows/CI/badge.svg" alt="Github Actions CI Status" /></a>
<a href="https://bytecodealliance.zulipchat.com/#narrow/stream/206238-general"><img src="https://img.shields.io/badge/zulip-join_chat-brightgreen.svg" alt="zulip chat" /></a>
<a href="https://crates.io/crates/rustix"><img src="https://img.shields.io/crates/v/rustix.svg" alt="crates.io page" /></a>
<a href="https://docs.rs/rustix"><img src="https://docs.rs/rustix/badge.svg" alt="docs.rs docs" /></a>
</p>
</div>
`rustix` provides efficient memory-safe and [I/O-safe] wrappers to POSIX-like,
Unix-like, Linux, and Winsock2 syscall-like APIs, with configurable backends.
It uses Rust references, slices, and return values instead of raw pointers, and
[I/O safety types] instead of raw file descriptors, providing memory safety,
[I/O safety], and [provenance]. It uses `Result`s for reporting errors,
[`bitflags`] instead of bare integer flags, an [`Arg`] trait with optimizations
to efficiently accept any Rust string type, and several other efficient
conveniences.
`rustix` is low-level and, and while the `net` API supports Winsock2 on
Windows, the rest of the APIs do not support Windows; for higher-level and more
portable APIs built on this functionality, see the [`cap-std`], [`memfd`],
[`timerfd`], and [`io-streams`] crates, for example.
`rustix` currently has two backends available:
* linux_raw, which uses raw Linux system calls and vDSO calls, and is
supported on Linux on x86-64, x86, aarch64, riscv64gc, powerpc64le,
arm (v5 onwards), mipsel, and mips64el, with stable, nightly, and 1.63 Rust.
- By being implemented entirely in Rust, avoiding `libc`, `errno`, and pthread
cancellation, and employing some specialized optimizations, most functions
compile down to very efficient code, which can often be fully inlined into
user code.
- Most functions in `linux_raw` preserve memory, I/O safety, and pointer
provenance all the way down to the syscalls.
* libc, which uses the [`libc`] crate which provides bindings to native `libc`
libraries on Unix-family platforms, and [`windows-sys`] for Winsock2 on
Windows, and is portable to many OS's.
The linux_raw backend is enabled by default on platforms which support it. To
enable the libc backend instead, either enable the "use-libc" cargo feature,
or set the `RUSTFLAGS` environment variable to `--cfg=rustix_use_libc` when
building.
## Cargo features
The modules [`rustix::io`], [`rustix::fd`], and [`rustix::ffi`] are enabled
by default. The rest of the API is conditional with cargo feature flags:
| Name | Description |
| ---------- | -------------------------------------------------------------- |
| `event` | [`rustix::event`]—Polling and event operations. |
| `fs` | [`rustix::fs`]—Filesystem operations. |
| `io_uring` | [`rustix::io_uring`]—Linux io_uring. |
| `mm` | [`rustix::mm`]—Memory map operations. |
| `mount` | [`rustix::mount`]—Linux mount API. |
| `net` | [`rustix::net`]—Network-related operations. |
| `param` | [`rustix::param`]—Process parameters. |
| `pipe` | [`rustix::pipe`]—Pipe operations. |
| `process` | [`rustix::process`]—Process-associated operations. |
| `procfs` | [`rustix::procfs`]—Utilities for reading `/proc` on Linux. |
| `pty` | [`rustix::pty`]—Pseudoterminal operations. |
| `rand` | [`rustix::rand`]—Random-related operations. |
| `shm` | [`rustix::shm`]—POSIX shared memory. |
| `stdio` | [`rustix::stdio`]—Stdio-related operations. |
| `system` | [`rustix::system`]—System-related operations. |
| `termios` | [`rustix::termios`]—Terminal I/O stream operations. |
| `thread` | [`rustix::thread`]—Thread-associated operations. |
| `time` | [`rustix::time`]—Time-related operations. |
| | |
| `use-libc` | Enable the libc backend. |
[`rustix::event`]: https://docs.rs/rustix/*/rustix/event/index.html
[`rustix::fs`]: https://docs.rs/rustix/*/rustix/fs/index.html
[`rustix::io_uring`]: https://docs.rs/rustix/*/rustix/io_uring/index.html
[`rustix::mm`]: https://docs.rs/rustix/*/rustix/mm/index.html
[`rustix::mount`]: https://docs.rs/rustix/*/rustix/mount/index.html
[`rustix::net`]: https://docs.rs/rustix/*/rustix/net/index.html
[`rustix::param`]: https://docs.rs/rustix/*/rustix/param/index.html
[`rustix::pipe`]: https://docs.rs/rustix/*/rustix/pipe/index.html
[`rustix::process`]: https://docs.rs/rustix/*/rustix/process/index.html
[`rustix::procfs`]: https://docs.rs/rustix/*/rustix/procfs/index.html
[`rustix::pty`]: https://docs.rs/rustix/*/rustix/pty/index.html
[`rustix::rand`]: https://docs.rs/rustix/*/rustix/rand/index.html
[`rustix::shm`]: https://docs.rs/rustix/*/rustix/shm/index.html
[`rustix::stdio`]: https://docs.rs/rustix/*/rustix/stdio/index.html
[`rustix::system`]: https://docs.rs/rustix/*/rustix/system/index.html
[`rustix::termios`]: https://docs.rs/rustix/*/rustix/termios/index.html
[`rustix::thread`]: https://docs.rs/rustix/*/rustix/thread/index.html
[`rustix::time`]: https://docs.rs/rustix/*/rustix/time/index.html
[`rustix::io`]: https://docs.rs/rustix/*/rustix/io/index.html
[`rustix::fd`]: https://docs.rs/rustix/*/rustix/fd/index.html
[`rustix::ffi`]: https://docs.rs/rustix/*/rustix/ffi/index.html
## 64-bit Large File Support (LFS) and Year 2038 (y2038) support
`rustix` automatically uses 64-bit APIs when available, and avoids exposing
32-bit APIs that would have the year-2038 problem or fail to support large
files. For instance, `rustix::fstatvfs` calls `fstatvfs64`, and returns a
struct that's 64-bit even on 32-bit platforms.
## Similar crates
`rustix` is similar to [`nix`], [`simple_libc`], [`unix`], [`nc`], [`uapi`],
and [`rusl`]. `rustix` is architected for [I/O safety] with most APIs using
[`OwnedFd`] and [`AsFd`] to manipulate file descriptors rather than `File` or
even `c_int`, and supporting multiple backends so that it can use direct
syscalls while still being usable on all platforms `libc` supports. Like `nix`,
`rustix` has an optimized and flexible filename argument mechanism that allows
users to use a variety of string types, including non-UTF-8 string types.
[`relibc`] is a similar project which aims to be a full "libc", including
C-compatible interfaces and higher-level C/POSIX standard-library
functionality; `rustix` just aims to provide safe and idiomatic Rust interfaces
to low-level syscalls. `relibc` also doesn't tend to support features not
supported on Redox, such as `*at` functions like `openat`, which are important
features for `rustix`.
`rustix` has its own code for making direct syscalls, similar to the
[`syscall`], [`sc`], and [`scall`] crates, using the Rust `asm!` macro.
`rustix` can also use Linux's vDSO mechanism to optimize Linux `clock_gettime`
on all architectures, and all Linux system calls on x86. And `rustix`'s
syscalls report errors using an optimized `Errno` type.
`rustix`'s `*at` functions are similar to the [`openat`] crate, but `rustix`
provides them as free functions rather than associated functions of a `Dir`
type. `rustix`'s `CWD` constant exposes the special `AT_FDCWD` value in a safe
way, so users don't need to open `.` to get a current-directory handle.
`rustix`'s `openat2` function is similar to the [`openat2`] crate, but uses I/O
safety types rather than `RawFd`. `rustix` does not provide dynamic feature
detection, so users must handle the [`NOSYS`] error themselves.
`rustix`'s `termios` module is similar to the [`termios`] crate, but uses I/O
safety types rather than `RawFd`, and the flags parameters to functions such as
`tcsetattr` are `enum`s rather than bare integers. And, rustix calls its
`tcgetattr` function `tcgetattr`, rather than `Termios::from_fd`.
## Minimum Supported Rust Version (MSRV)
This crate currently works on the version of [Rust on Debian stable], which is
currently [Rust 1.63]. This policy may change in the future, in minor version
releases, so users using a fixed version of Rust should pin to a specific
version of this crate.
## Minimum Linux Version
On Linux platforms, rustix requires at least Linux 3.2. This is at most the
oldest Linux version supported by:
- [any current Rust target], or
- [kernel.org] at the time of rustix's [MSRV] release.
The specifics of this policy may change in the future, but we intend it to
always reflect “very old” Linux versions.
[MSRV]: #minimum-supported-rust-version-msrv
[Rust 1.63]: https://blog.rust-lang.org/2022/08/11/Rust-1.63.0.html
[any current Rust target]: https://doc.rust-lang.org/nightly/rustc/platform-support.html
[kernel.org]: https://www.kernel.org/releases.html
[Rust on Debian stable]: https://packages.debian.org/stable/rust/rustc
[`nix`]: https://crates.io/crates/nix
[`unix`]: https://crates.io/crates/unix
[`nc`]: https://crates.io/crates/nc
[`simple_libc`]: https://crates.io/crates/simple_libc
[`uapi`]: https://crates.io/crates/uapi
[`rusl`]: https://lib.rs/crates/rusl
[`relibc`]: https://gitlab.redox-os.org/redox-os/relibc
[`syscall`]: https://crates.io/crates/syscall
[`sc`]: https://crates.io/crates/sc
[`scall`]: https://crates.io/crates/scall
[`openat`]: https://crates.io/crates/openat
[`openat2`]: https://crates.io/crates/openat2
[I/O safety types]: https://doc.rust-lang.org/stable/std/os/fd/index.html#structs
[`termios`]: https://crates.io/crates/termios
[`libc`]: https://crates.io/crates/libc
[`windows-sys`]: https://crates.io/crates/windows-sys
[`cap-std`]: https://crates.io/crates/cap-std
[`memfd`]: https://crates.io/crates/memfd
[`timerfd`]: https://crates.io/crates/timerfd
[`io-streams`]: https://crates.io/crates/io-streams
[`bitflags`]: https://crates.io/crates/bitflags
[`Arg`]: https://docs.rs/rustix/*/rustix/path/trait.Arg.html
[I/O-safe]: https://github.com/rust-lang/rfcs/blob/master/text/3128-io-safety.md
[I/O safety]: https://github.com/rust-lang/rfcs/blob/master/text/3128-io-safety.md
[provenance]: https://github.com/rust-lang/rust/issues/95228
[`OwnedFd`]: https://doc.rust-lang.org/stable/std/os/fd/struct.OwnedFd.html
[`AsFd`]: https://doc.rust-lang.org/stable/std/os/fd/trait.AsFd.html
[`NOSYS`]: https://docs.rs/rustix/*/rustix/io/struct.Errno.html#associatedconstant.NOSYS
|
