blink.rs

extern crate sysfs_gpio;

use sysfs_gpio::{Direction,Pin};
use std::time::Duration;
use std::thread::sleep;

fn main() {
    let led = Pin::new(16);
    led.with_exported(|| {
        sleep(Duration::from_millis(1000));
        try!(led.set_direction(Direction::Low));
        for _ in 0..10 {
            println!("GO!");
            try!(led.set_value(0));
            sleep(Duration::from_millis(1000));
            try!(led.set_value(1));
            sleep(Duration::from_millis(1000));
        }
        led.set_value(0)
    }).unwrap();
}

open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libgcc_s.so.1", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/librt.so.1", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
open("/usr/lib/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
open("/sys/devices/system/cpu/online", O_RDONLY|O_CLOEXEC) = 3
open("/proc/self/maps", O_RDONLY|O_CLOEXEC) = 3
open("/sys/class/gpio/export", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE|O_CLOEXEC, 0666) = 3
open("/sys/class/gpio/gpio16/direction", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE|O_CLOEXEC, 0666) = -1 EACCES (Permission denied)
open("/sys/class/gpio/unexport", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE|O_CLOEXEC, 0666) = 3
thread '<main>' panicked at 'called `Result::unwrap()` on an `Err` value: Io(Error { repr: Os { code: 13, message: "Permission denied" } })', /buildslave/rust-buildbot/slave/nightly-dist-rustc-cross-host-linux/build/src/libcore/result.rs:785
note: Run with `RUST_BACKTRACE=1` for a backtrace.
+++ exited with 101 +++

udev rule:

SUBSYSTEM=="gpio*", PROGRAM="/bin/sh -c '\
    chown -R root:gpio /sys/class/gpio && chmod -R 770 /sys/class/gpio;
    chown -R root:gpio /sys$devpath && chmod -R 770 /sys$devpath\
'"