coreutils/comm/comm.rs
Brian Anderson bad19f6016 Remove tail return statements.
Per review feedback.
2014-06-11 21:48:38 -07:00

140 lines
3.9 KiB
Rust

#![crate_id(name="comm", vers="1.0.0", author="Michael Gehring")]
/*
* This file is part of the uutils coreutils package.
*
* (c) Michael Gehring <mg@ebfe.org>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
extern crate getopts;
use std::cmp::Ord;
use std::io::{BufferedReader, IoResult, print};
use std::io::fs::File;
use std::io::stdio::stdin;
use std::os;
use std::path::Path;
static NAME : &'static str = "comm";
static VERSION : &'static str = "1.0.0";
fn mkdelim(col: uint, opts: &getopts::Matches) -> String {
let mut s = String::new();
let delim = match opts.opt_str("output-delimiter") {
Some(d) => d.clone(),
None => "\t".to_string(),
};
if col > 1 && !opts.opt_present("1") {
s.push_str(delim.as_slice());
}
if col > 2 && !opts.opt_present("2") {
s.push_str(delim.as_slice());
}
s
}
fn ensure_nl(line: String) -> String {
match line.as_slice().chars().last() {
Some('\n') => line,
_ => line.append("\n"),
}
}
fn comm(a: &mut Box<Buffer>, b: &mut Box<Buffer>, opts: &getopts::Matches) {
let delim = Vec::from_fn(4, |col| mkdelim(col, opts));
let mut ra = a.read_line();
let mut rb = b.read_line();
while ra.is_ok() || rb.is_ok() {
let ord = match (ra.clone(), rb.clone()) {
(Err(_), Ok(_)) => Greater,
(Ok(_) , Err(_)) => Less,
(Ok(s0), Ok(s1)) => s0.cmp(&s1),
_ => unreachable!(),
};
match ord {
Less => {
if !opts.opt_present("1") {
print!("{}{}", delim.get(1), ra.map(ensure_nl).unwrap());
}
ra = a.read_line();
}
Greater => {
if !opts.opt_present("2") {
print!("{}{}", delim.get(2), rb.map(ensure_nl).unwrap());
}
rb = b.read_line();
}
Equal => {
if !opts.opt_present("3") {
print!("{}{}", delim.get(3), ra.map(ensure_nl).unwrap());
}
ra = a.read_line();
rb = b.read_line();
}
}
}
}
fn open_file(name: &str) -> IoResult<Box<Buffer>> {
match name {
"-" => Ok(box stdin() as Box<Buffer>),
_ => {
let f = try!(File::open(&Path::new(name)));
Ok(box BufferedReader::new(f) as Box<Buffer>)
}
}
}
#[allow(dead_code)]
fn main() { os::set_exit_status(uumain(os::args())); }
pub fn uumain(args: Vec<String>) -> int {
let opts = [
getopts::optflag("1", "", "suppress column 1 (lines uniq to FILE1)"),
getopts::optflag("2", "", "suppress column 2 (lines uniq to FILE2)"),
getopts::optflag("3", "", "suppress column 3 (lines that appear in both files)"),
getopts::optopt("", "output-delimiter", "separate columns with STR", "STR"),
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(err) => fail!("{}", err.to_err_msg()),
};
if matches.opt_present("version") {
println!("{} {}", NAME, VERSION);
return 0;
}
if matches.opt_present("help") || matches.free.len() != 2 {
println!("{} {}", NAME, VERSION);
println!("");
println!("Usage:");
println!(" {} [OPTIONS] FILE1 FILE2", NAME);
println!("");
print(getopts::usage("Compare sorted files line by line.", opts.as_slice()).as_slice());
if matches.free.len() != 2 {
return 0;
}
return 0;
}
let mut f1 = open_file(matches.free.get(0).as_slice()).unwrap();
let mut f2 = open_file(matches.free.get(1).as_slice()).unwrap();
comm(&mut f1, &mut f2, &matches);
0
}