A Bytecode Alliance project
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 target the raw
Linux syscall ABI directly instead of calling through libc. To enable this,
add --cfg linux_raw to the RUSTFLAGS environment variable, or otherwise
pass --cfg linux_raw to rustc. This mode is new, and so far only tested on
x86-64, but a fair amount of code has been successfully adapted to use it,
and ports to other architectures should be straightforward.
This feature has two fun properties:
- By being implemented in Rust, avoiding
libc,errno, andstd::io::Error, most functions compile down to very simple code and can even be fully inlined into user code. - Memory buffers are kept in Rust slices, and file descriptors are kept in
io-lifetimestypes, so most functions preserve memory safety and I/O safety all the way down to the syscall.