coreutils/tee/tee.rs
pabzdzdzwiagief f1e8a30872 Implement tee
2013-12-23 18:12:26 +01:00

108 lines
3.4 KiB
Rust

#[link(name="tee", vers="1.0.0", author="Aleksander Bielawski")];
/*
* This file is part of the uutils coreutils package.
*
* (c) Aleksander Bielawski <pabzdzdzwiagief@gmail.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
extern mod extra;
use std::io::{stdin, stdout, Append, File, Truncate, Write};
use std::io::{io_error, result, EndOfFile};
use std::io::signal::{Interrupt, Listener};
use std::io::util::{copy, MultiWriter};
use std::os::{args, set_exit_status};
use extra::getopts::groups::{getopts, optflag, usage};
static NAME: &'static str = "tee";
static VERSION: &'static str = "1.0.0";
fn main() {
match options(args()).and_then(exec) {
Err(message) => {
error!("{}: {}", args()[0], message);
set_exit_status(1)
},
Ok(status) => set_exit_status(status)
}
}
struct Options {
program: ~str,
append: bool,
ignore_interrupts: bool,
print_and_exit: Option<~str>,
files: ~[Path]
}
fn options(args: &[~str]) -> Result<Options, ~str> {
let opts = ~[
optflag("a", "append", "append to the given FILEs, do not overwrite"),
optflag("i", "ignore-interrupts", "ignore interrupt signals"),
optflag("", "help", "display this help and exit"),
optflag("", "version", "output version information and exit")];
getopts(args.tail(), opts).map_err(|e| e.to_err_msg()).and_then(|m| {
let version = format!("{} {}", NAME, VERSION);
let program = args[0].clone();
let arguments = "[OPTION]... [FILE]...";
let brief = "Copy standard input to each FILE, and also to standard " +
"output.";
let comment = "If a FILE is -, copy again to standard output.";
let help = format!("{}\n\nUsage:\n {} {}\n\n{}\n{}",
version, program, arguments, usage(brief, opts),
comment);
let names = m.free + ~[~"-"];
let to_print = if m.opt_present("help") { Some(help) }
else if m.opt_present("version") { Some(version) }
else { None };
Ok(Options {
program: program,
append: m.opt_present("append"),
ignore_interrupts: m.opt_present("ignore-interrupts"),
print_and_exit: to_print,
files: names.map(|name| Path::new(name.clone()))
})
})
}
fn open(path: &Path, append: bool) -> ~Writer {
if *path == Path::new("-") {
~stdout() as ~Writer
} else {
let mode = if append { Append } else { Truncate };
~File::open_mode(path, mode, Write) as ~Writer
}
}
fn exec(options: Options) -> Result<int, ~str> {
match options.print_and_exit {
Some(text) => {
println(text);
Ok(0)
},
None => tee(options)
}
}
fn tee(options: Options) -> Result<int, ~str> {
let mut handler = Listener::new();
if options.ignore_interrupts {
handler.register(Interrupt);
}
result(|| io_error::cond.trap(|e| {
if e.kind != EndOfFile {
io_error::cond.raise(e);
}
}).inside(|| {
let writers = options.files.map(|path| open(path, options.append));
let output = &mut MultiWriter::new(writers);
let input = &mut stdin();
copy(input, output);
output.flush();
0
})).map_err(|err| err.desc.to_owned())
}