example which invoke external process

invoke_external_process.rs

// 外部プロセス呼び出しサンプル
// 外部プロセスの標準出力・エラー出力はこのプロセスのものを使う

extern crate libc;
use std::io::{Command, IoResult};
use std::io::process::ProcessExit;
use std::io::process::ProcessExit::{ExitStatus, ExitSignal};
use std::io::process::StdioContainer::InheritFd;

// POSIX 以外だとどうなる？
use libc::consts::os::posix88::{STDOUT_FILENO, STDERR_FILENO};

fn main() {
    //match exec("sleep", &["10000"], 1000) { // long running process
    //match exec("foo", &[], 1000) { // invalid command
    //match exec("cat", &["foo"], 1000) { // error exit command
    match exec("echo", &["foo", "bar"], 1000) { // valid command
        Ok(ExitStatus(s)) => println!("exit: {}", s),
        Ok(ExitSignal(s)) => println!("received signal: {}", s),
        Err(_) => panic!("timeout"),
    }
}

fn exec(prog: &str, args: &[&str], timeout: u64) -> IoResult<ProcessExit> {
    let mut c = Command::new(prog);
    c.args(args)
        .stdout(InheritFd(STDOUT_FILENO))
        .stderr(InheritFd(STDERR_FILENO));

    let mut p = try!(c.spawn());
    p.set_timeout(Some(timeout));

    let r = p.wait();
    if r.is_err() {
        let _ = p.signal_kill();
    }

    r
}