coreutils/whoami/whoami.rs

#[crate_id(name="whoami", version="1.0.0", author="KokaKiwi")];

/*
 * This file is part of the uutils coreutils package.
 *
 * (c) Jordi Boggiano <j.boggiano@seld.be>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/* last synced with: whoami (GNU coreutils) 8.21 */

extern mod extra;

use std::io::print;
use std::os;
use std::str;
use std::libc;
use extra::getopts::groups;

struct c_passwd {
    pw_name: *libc::c_char,
    // Maybe I should put here others struct members, but...Well, maybe.
}

extern {
    pub fn geteuid() -> libc::c_int;
    pub fn getpwuid(uid: libc::c_int) -> *c_passwd;
}

unsafe fn getusername() -> ~str {
    let passwd: *c_passwd = getpwuid(geteuid());

    let pw_name: *libc::c_char = (*passwd).pw_name;
    let name = str::raw::from_c_str(pw_name);

    name
}

fn main() {
    let args = os::args();
    let program = args[0].as_slice();
    let opts = ~[
        groups::optflag("h", "help", "display this help and exit"),
        groups::optflag("V", "version", "output version information and exit"),
    ];
    let matches = match groups::getopts(args.tail(), opts) {
        Ok(m) => m,
        Err(f) => fail!(f.to_err_msg()),
    };
    if matches.opt_present("help") {
        println!("whoami 1.0.0");
        println!("");
        println!("Usage:");
        println!("  {:s}", program);
        println!("");
        print(groups::usage("print effective userid", opts));
        return;
    }
    if matches.opt_present("version") {
        println!("whoami 1.0.0");
        return;
    }

    exec();
}

pub fn exec() {
    unsafe {
        let username = getusername();
        println!("{:s}", username);
    }
}