Crate dynlink 

Cross-platform dynamic linking.

This library provides a platform-independent API that allows dynamic linking shared objects, and use the data and functions they contains.

Usage

With this library shared object functions can be used.

use std::error;

use dynlink::api::Handle;

// sum.c
//
// int sum_of(int a, int b) {
//    return a + b;
// }

fn main() -> Result<(), Box<dyn error::Error>> {
    unsafe {
        let handle = Handle::open("libsum.so")?;
        let sum_fn = handle.lookup::<extern "C" fn(i32, i32) -> i32>("sum_of")?;

        println!("{}", sum_fn.apply(|f| f(1, 1)));

        Ok(())
    }
}

The main purpose of this library is to write safe (or unsafe) wrappers for shared objects.

use std::error;

use dynlink::api::Handle;

// sum.c
//
// int sum_of(int a, int b) {
//    return a + b;
// }

struct MathLib {
    // symbols must not outlive the handle that owns them
    _handle: Handle,
    sum_fn: extern "C" fn(i32, i32) -> i32,
}

impl MathLib {
    pub fn load() -> Result<Self, Box<dyn error::Error>> {
        unsafe {
            let handle = Handle::open("libsum.so")?;
            let sum_fn = handle.lookup("sum_of")?.leak();

            Ok(Self {
                _handle: handle,
                sum_fn: sum_fn,
            })
        }
    }

    pub fn sum(&self, a: i32, b: i32) -> i32 {
        (self.sum_fn)(a, b)
    }
}

fn main() -> Result<(), Box<dyn error::Error>> {
    let mathlib = MathLib::load()?;
    println!("{}", mathlib.sum(1, 1));

    Ok(())
}

Platform-specific APIs are also available in the platform module.

#![cfg(target_os = "linux")]

use std::error;

use dynlink::platform::{PlatformHandle, RTLD_LAZY, RTLD_LOCAL};

fn main() -> Result<(), Box<dyn error::Error>> {
    unsafe {
        let handle = PlatformHandle::openc(c"libsum.so", RTLD_LOCAL | RTLD_LAZY)?;
        let sum_fn = handle.lookupc::<extern "C" fn(i32, i32) -> i32>(c"sum_of")?;

        println!("{}", sum_fn.apply(|f| f(1, 1)));

        Ok(())
    }
}

Modules

api

platform