posish

posish provides efficient memory-safe and [I/O-safe] wrappers to "POSIX-ish" libc APIs and syscalls.

posish is relatively low-level and does not support Windows; for higher-level and portable APIs to this functionality, see the [system-interface], [cap-std], and [fs-set-times] crates.

Linux raw syscall support

On Linux, posish can optionally be configured to use the raw Linux syscall ABI directly instead of libc. To enable this, use Rust nightly, and set the RUSTFLAGS environment variable to --cfg linux_raw, or otherwise pass --cfg linux_raw to rustc. This mode is new, and so far only supports x86-64 and aarch64, but a fair amount of code has been successfully adapted to use it, and ports to most other architectures should be straightforward.

This feature is fun in two ways: - By being implemented entirely in Rust, avoiding libc, errno, and pthread cancellation, and using type layout optimizations and an optimized error type, most functions compile down to very simple code and can even be fully inlined into user code. - Memory buffers are kept in Rust slices, out parameters are returned as regular values, and file descriptors are kept in [io-lifetimes] types, so most functions preserve memory safety and I/O safety all the way down to the syscalls.