Crate posish

posish provides safe wrappers to libc functions. The current focus is on the functionality needed by cap-std and system-interface that isn't provided by std or getrandom.

The wrappers perform the following tasks:

• Error values are translated to Results.
• Out-parameters are translated to return values.
• Path arguments can by any kind of string type.
• File descriptors are passed in through arguments implementing AsRawFd instead of as bare integers and returned as std::fs::Files.
• Constants use enums and bitflags types.
• Multiplexed functions (eg. fcntl, ioctl, etc.) are de-multiplexed.
• Variadic functions (eg. openat, etc.) are presented as non-variadic.
• Functions and types which need 64 suffixes to enable large-file support are used automatically.
• Behaviors that depend on the sizes of C types like long are hidden.
• File offsets and sizes are presented as i64 and u64 rather than off_t.
• In some places, more human-friendly and less historical-accident names are used.

Things they don't do include:

• Emulating functions that aren't natively supported on a platform.
• Detecting whether functions are supported at runtime.
• Hiding significant differences between platforms.
• Hiding ambient authorities.
• Imposing sandboxing features such as filesystem path or network address sandboxing.

See cap-std and system-interface for libraries which do hide ambient authorities and perform sandboxing.

Safety

This library follows std in considering dynamic integer values that have no meaning outside of OS APIs to be similar to raw pointers, from a safety perspective. For example, std::os::unix::io::FromRawFd::from_raw_fd is unsafe since it takes a raw file descriptor. In this library, raw file descriptors and raw directory seek locations are considered to be similar to raw pointers in terms of safety.

Modules

fs	Filesystem operations.
io	I/O operations.
net	Network-related operations.
path	Filesystem path operations.
process	Process-associated operations.
time	Time-related operations.