use std::cmp::Ordering;
use std::fs::File;
use std::io::{self, stdin, BufRead, BufReader, Stdin};
use std::path::Path;
use uucore::error::{FromIo, UResult};
use uucore::line_ending::LineEnding;
use uucore::{format_usage, help_about, help_usage};
use clap::{crate_version, Arg, ArgAction, ArgMatches, Command};
const ABOUT: &str = help_about!("comm.md");
const USAGE: &str = help_usage!("comm.md");
mod options {
pub const COLUMN_1: &str = "1";
pub const COLUMN_2: &str = "2";
pub const COLUMN_3: &str = "3";
pub const DELIMITER: &str = "output-delimiter";
pub const DELIMITER_DEFAULT: &str = "\t";
pub const FILE_1: &str = "FILE1";
pub const FILE_2: &str = "FILE2";
pub const TOTAL: &str = "total";
pub const ZERO_TERMINATED: &str = "zero-terminated";
}
enum Input {
Stdin(Stdin),
FileIn(BufReader<File>),
}
struct LineReader {
line_ending: LineEnding,
input: Input,
}
impl LineReader {
fn new(input: Input, line_ending: LineEnding) -> Self {
Self { input, line_ending }
}
fn read_line(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
let line_ending = self.line_ending.into();
let result = match &mut self.input {
Input::Stdin(r) => r.lock().read_until(line_ending, buf),
Input::FileIn(r) => r.read_until(line_ending, buf),
};
if !buf.ends_with(&[line_ending]) {
buf.push(line_ending);
}
result
}
}
fn comm(a: &mut LineReader, b: &mut LineReader, opts: &ArgMatches) {
let delim = match opts.get_one::<String>(options::DELIMITER).unwrap().as_str() {
"" => "\0",
delim => delim,
};
let width_col_1 = usize::from(!opts.get_flag(options::COLUMN_1));
let width_col_2 = usize::from(!opts.get_flag(options::COLUMN_2));
let delim_col_2 = delim.repeat(width_col_1);
let delim_col_3 = delim.repeat(width_col_1 + width_col_2);
let ra = &mut Vec::new();
let mut na = a.read_line(ra);
let rb = &mut Vec::new();
let mut nb = b.read_line(rb);
let mut total_col_1 = 0;
let mut total_col_2 = 0;
let mut total_col_3 = 0;
while na.is_ok() || nb.is_ok() {
let ord = match (na.is_ok(), nb.is_ok()) {
(false, true) => Ordering::Greater,
(true, false) => Ordering::Less,
(true, true) => match (&na, &nb) {
(&Ok(0), &Ok(0)) => break,
(&Ok(0), _) => Ordering::Greater,
(_, &Ok(0)) => Ordering::Less,
_ => ra.cmp(&rb),
},
_ => unreachable!(),
};
match ord {
Ordering::Less => {
if !opts.get_flag(options::COLUMN_1) {
print!("{}", String::from_utf8_lossy(ra));
}
ra.clear();
na = a.read_line(ra);
total_col_1 += 1;
}
Ordering::Greater => {
if !opts.get_flag(options::COLUMN_2) {
print!("{delim_col_2}{}", String::from_utf8_lossy(rb));
}
rb.clear();
nb = b.read_line(rb);
total_col_2 += 1;
}
Ordering::Equal => {
if !opts.get_flag(options::COLUMN_3) {
print!("{delim_col_3}{}", String::from_utf8_lossy(ra));
}
ra.clear();
rb.clear();
na = a.read_line(ra);
nb = b.read_line(rb);
total_col_3 += 1;
}
}
}
if opts.get_flag(options::TOTAL) {
let line_ending = LineEnding::from_zero_flag(opts.get_flag(options::ZERO_TERMINATED));
print!("{total_col_1}{delim}{total_col_2}{delim}{total_col_3}{delim}total{line_ending}");
}
}
fn open_file(name: &str, line_ending: LineEnding) -> io::Result<LineReader> {
if name == "-" {
Ok(LineReader::new(Input::Stdin(stdin()), line_ending))
} else {
let f = File::open(Path::new(name))?;
Ok(LineReader::new(
Input::FileIn(BufReader::new(f)),
line_ending,
))
}
}
#[uucore::main]
pub fn uumain(args: impl uucore::Args) -> UResult<()> {
let args = args.collect_lossy();
let matches = uu_app().try_get_matches_from(args)?;
let line_ending = LineEnding::from_zero_flag(matches.get_flag(options::ZERO_TERMINATED));
let filename1 = matches.get_one::<String>(options::FILE_1).unwrap();
let filename2 = matches.get_one::<String>(options::FILE_2).unwrap();
let mut f1 = open_file(filename1, line_ending).map_err_context(|| filename1.to_string())?;
let mut f2 = open_file(filename2, line_ending).map_err_context(|| filename2.to_string())?;
comm(&mut f1, &mut f2, &matches);
Ok(())
}
pub fn uu_app() -> Command {
Command::new(uucore::util_name())
.version(crate_version!())
.about(ABOUT)
.override_usage(format_usage(USAGE))
.infer_long_args(true)
.arg(
Arg::new(options::COLUMN_1)
.short('1')
.help("suppress column 1 (lines unique to FILE1)")
.action(ArgAction::SetTrue),
)
.arg(
Arg::new(options::COLUMN_2)
.short('2')
.help("suppress column 2 (lines unique to FILE2)")
.action(ArgAction::SetTrue),
)
.arg(
Arg::new(options::COLUMN_3)
.short('3')
.help("suppress column 3 (lines that appear in both files)")
.action(ArgAction::SetTrue),
)
.arg(
Arg::new(options::DELIMITER)
.long(options::DELIMITER)
.help("separate columns with STR")
.value_name("STR")
.default_value(options::DELIMITER_DEFAULT)
.hide_default_value(true),
)
.arg(
Arg::new(options::ZERO_TERMINATED)
.long(options::ZERO_TERMINATED)
.short('z')
.overrides_with(options::ZERO_TERMINATED)
.help("line delimiter is NUL, not newline")
.action(ArgAction::SetTrue),
)
.arg(
Arg::new(options::FILE_1)
.required(true)
.value_hint(clap::ValueHint::FilePath),
)
.arg(
Arg::new(options::FILE_2)
.required(true)
.value_hint(clap::ValueHint::FilePath),
)
.arg(
Arg::new(options::TOTAL)
.long(options::TOTAL)
.help("output a summary")
.action(ArgAction::SetTrue),
)
}