coreutils/tee/tee.rs
2014-05-28 08:33:39 +02:00

154 lines
4.7 KiB
Rust

#![crate_id(name="tee", vers="1.0.0", author="Aleksander Bielawski")]
#![license="MIT"]
#![feature(phase)]
#![feature(macro_rules)]
/*
* 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 crate getopts;
#[phase(syntax, link)] extern crate log;
use std::io::{println, stdin, stdout, Append, File, Truncate, Write};
use std::io::{IoResult};
use std::io::util::{copy, NullWriter, MultiWriter};
use std::os::{args, set_exit_status};
use getopts::{getopts, optflag, usage};
static NAME: &'static str = "tee";
static VERSION: &'static str = "1.0.0";
fn main() {
match options(args().as_slice()).and_then(exec) {
Ok(_) => set_exit_status(0),
Err(_) => set_exit_status(1)
}
}
struct Options {
program: String,
append: bool,
ignore_interrupts: bool,
print_and_exit: Option<String>,
files: Box<Vec<Path>>
}
fn options(args: &[String]) -> Result<Options, ()> {
let opts = ~[
optflag("a", "append", "append to the given FILEs, do not overwrite"),
optflag("i", "ignore-interrupts", "ignore interrupt signals"),
optflag("h", "help", "display this help and exit"),
optflag("V", "version", "output version information and exit"),
];
let args: Vec<String> = args.iter().map(|x| x.to_string()).collect();
getopts(args.tail(), opts).map_err(|e| e.to_err_msg()).and_then(|m| {
let version = format!("{} {}", NAME, VERSION);
let program = args.get(0).as_slice();
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.clone().move_iter().collect::<Vec<String>>().append_one("-".to_string());
let to_print = if m.opt_present("help") { Some(help) }
else if m.opt_present("version") { Some(version) }
else { None };
Ok(Options {
program: program.to_string(),
append: m.opt_present("append"),
ignore_interrupts: m.opt_present("ignore-interrupts"),
print_and_exit: to_print,
files: box names.iter().map(|name| Path::new(name.clone())).collect()
})
}).map_err(|message| warn(message.as_slice()))
}
fn exec(options: Options) -> Result<(), ()> {
match options.print_and_exit {
Some(text) => Ok(println(text.as_slice())),
None => tee(options)
}
}
fn tee(options: Options) -> Result<(), ()> {
let writers = options.files.iter().map(|path| open(path, options.append)).collect();
let output = &mut MultiWriter::new(writers);
let input = &mut NamedReader { inner: box stdin() as Box<Reader> };
if copy(input, output).is_err() || output.flush().is_err() {
Err(())
} else {
Ok(())
}
}
fn open(path: &Path, append: bool) -> Box<Writer> {
let inner = if *path == Path::new("-") {
box stdout() as Box<Writer>
} else {
let mode = if append { Append } else { Truncate };
match File::open_mode(path, mode, Write) {
Ok(file) => box file as Box<Writer>,
Err(_) => box NullWriter as Box<Writer>
}
};
box NamedWriter { inner: inner, path: box path.clone() } as Box<Writer>
}
struct NamedWriter {
inner: Box<Writer>,
path: Box<Path>
}
impl Writer for NamedWriter {
fn write(&mut self, buf: &[u8]) -> IoResult<()> {
with_path(self.path.clone(), || {
let val = self.inner.write(buf);
if val.is_err() {
self.inner = box NullWriter as Box<Writer>;
}
val
})
}
fn flush(&mut self) -> IoResult<()> {
with_path(self.path.clone(), || {
let val = self.inner.flush();
if val.is_err() {
self.inner = box NullWriter as Box<Writer>;
}
val
})
}
}
struct NamedReader {
inner: Box<Reader>
}
impl Reader for NamedReader {
fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
with_path(&Path::new("stdin"), || {
self.inner.read(buf)
})
}
}
fn with_path<T>(path: &Path, cb: || -> IoResult<T>) -> IoResult<T> {
match cb() {
Err(f) => { warn(format!("{}: {}", path.display(), f.to_str()).as_slice()); Err(f) }
okay => okay
}
}
fn warn(message: &str) {
error!("{}: {}", args().get(0), message);
}