coreutils/src/cat.rs

// Copyright (c) 2022 YAC
// SPDX-License-Identifier: AGPL-3.0-or-later

/* This file is part of YAC coreutils.
 *
 * YAC coreutils is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Affero General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * YAC coreutils is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see https://www.gnu.org/licenses/.
 */

use std::env;
use std::fs::{File, read, read_to_string};
use std::io;
use std::io::{ Read, Write };
use std::os::unix::io::FromRawFd;
use std::str;

use arg::Args;

use sysexits::ExitCode;

#[derive(Args, Debug)]
struct Arguments {
  #[arg(short = "u")]
  u: bool,

  paths: Vec<String>,
}

fn main() -> ExitCode {
  let mut arguments = env::args().collect::<Vec<String>>();
  let argv0 = arguments.remove(0);

  let mut args = Arguments::from_args(arguments
    .iter()
    .map(String::as_str)
    .collect::<Vec<&str>>()
  ).unwrap();

  let mut output = String::new();

  if args.paths.is_empty() { args.paths.push("-".to_string()); }

  for path in args.paths {
    if path == "-" {
      let mut bytes: Vec<u8> = Vec::new();
      io::stdin().lock().read_to_end(&mut bytes).unwrap();

      for byte in &bytes {
        output.push_str(str::from_utf8(&[byte.to_owned()]).unwrap());
      }
    } else {
      match read_to_string(&path) {
        Ok(contents) => { output.push_str(&contents) },
        Err(_) => {
          eprintln!("{}: {}: No such file or directory.", &argv0, &path);
          return ExitCode::NoInput;
        },
      };
    }
    print!("{}", output);
    output.clear();
  }
  ExitCode::Ok
}