coreutils/printenv/printenv.rs
2014-05-23 14:28:40 +02:00

81 lines
2.2 KiB
Rust

#![crate_id(name="printenv", vers="1.0.0", author="Seldaek")]
/*
* 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: printenv (GNU coreutils) 8.13 */
#![feature(macro_rules)]
extern crate getopts;
extern crate libc;
use std::os;
use std::io::print;
#[path = "../common/util.rs"]
mod util;
static NAME: &'static str = "printenv";
fn main() {
let args: Vec<StrBuf> = os::args().iter().map(|x| x.to_strbuf()).collect();
let program = args.get(0).clone();
let opts = ~[
getopts::optflag("0", "null", "end each output line with 0 byte rather than newline"),
getopts::optflag("h", "help", "display this help and exit"),
getopts::optflag("V", "version", "output version information and exit"),
];
let matches = match getopts::getopts(args.tail(), opts) {
Ok(m) => m,
Err(f) => {
crash!(1, "Invalid options\n{}", f.to_err_msg())
}
};
if matches.opt_present("help") {
println!("printenv 1.0.0");
println!("");
println!("Usage:");
println!(" {0:s} [VARIABLE]... [OPTION]...", program);
println!("");
print(getopts::usage("Prints the given environment VARIABLE(s), otherwise prints them all.", opts).as_slice());
return;
}
if matches.opt_present("version") {
println!("printenv 1.0.0");
return;
}
let mut separator = "\n";
if matches.opt_present("null") {
separator = "\x00";
};
exec(matches.free, separator);
}
pub fn exec(args: Vec<StrBuf>, separator: &str) {
if args.is_empty() {
let vars = os::env();
for (env_var, value) in vars.move_iter() {
print!("{0:s}={1:s}", env_var, value);
print(separator);
}
return;
}
for env_var in args.iter() {
match os::getenv(env_var.as_slice()) {
Some(var) => {
print(var.as_slice());
print(separator);
}
_ => ()
}
}
}