First Rust program (apart from Hello, world) to actually learn something, since there appear to be no books yet and the thing keeps changing anyways

music-thing.rs

use std::io::{stdin, stdout};
use std::run;
use std::libc;
use std::libc::c_int;

static SIGCONT: c_int = 18;
static SIGSTOP: c_int = 19;

trait ProcessSignal {
	fn kill(&self, signal: c_int);
}

impl ProcessSignal for run::Process {
	fn kill(&self, signal: c_int) {
		unsafe {
			libc::funcs::posix88::signal::kill(self.get_id(), signal);
		}
	}
}

fn main() {
	let mut current_process: Option<run::Process> = None;

	loop {
		let input = stdin().read_line();
		let (action, argument) = {
			let mut command = input.splitn_iter(' ', 1);
			(command.next(), command.next())
		};

		match (action, argument) {
			(Some("play"), Some(track)) => {
				if current_process.is_some() {
					current_process.get_mut_ref().destroy();
				}

				let path = fmt!("/home/ryan/music/%s", track);
				let options = run::ProcessOptions {
					env: None,
					dir: None,
					in_fd: None,
					out_fd: None,
					err_fd: Some(2)
				};

				current_process = Some(run::Process::new("play", [path], options));
			},
			(Some("play"), None) => {
				if current_process.is_some() {
					current_process.get_ref().kill(SIGCONT);
				} else {
					fail!("No current process to pause!");
				}
			},
			(Some("pause"), None) => {
				if current_process.is_some() {
					current_process.get_ref().kill(SIGSTOP);
				} else {
					fail!("No current process to pause!");
				}
			},
			(Some("wtf"), None) => {
				let output = current_process.get_mut_ref().finish_with_output();

				println("Error:");
				stdout().write(output.error);
				println("Output:");
				stdout().write(output.output);
			},
			(Some(a), _) => println(fmt!("Unrecognized action %s", a)),
			_ => fail!()
		}
	}
}