coreutils/src/bin/coreutils.rs

// 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 lazy_static;
extern crate textwrap;
extern crate uucore;

use lazy_static::lazy_static;
use std::collections::hash_map::HashMap;
use std::io::Write;

static VERSION: &str = env!("CARGO_PKG_VERSION");

lazy_static! {
    static ref BINARY_PATH: std::path::PathBuf = {
        // support symlinks by using args[0], when possible, with fallback to current_exe()
        match std::env::args().next() {
            Some(ref s) if !s.is_empty() => std::path::PathBuf::from(s),
            _ => std::env::current_exe().unwrap(),
        }
    };
    static ref NAME: &'static str = &*BINARY_PATH.file_stem().unwrap().to_str().unwrap();
}

include!(concat!(env!("OUT_DIR"), "/uutils_map.rs"));

fn usage(utils: &UtilityMap) {
    println!("{} {} (multi-call binary)\n", *NAME, VERSION);
    println!("Usage: {} [function [arguments...]]\n", *NAME);
    println!("Currently defined functions/utilities:\n");
    #[allow(clippy::map_clone)]
    let mut utils: Vec<&str> = utils.keys().map(|&s| s).collect();
    utils.sort();
    let display_list = utils.join(", ");
    let width = std::cmp::min(textwrap::termwidth(), 100) - 4 * 2; // (opinion/heuristic) max 100 chars wide with 4 character side indentions
    println!(
        "{}",
        textwrap::indent(&textwrap::fill(&display_list, width), "    ")
    );
}

fn main() {
    uucore::panic::mute_sigpipe_panic();

    let utils = util_map();
    let mut args: Vec<String> = uucore::args().collect();

    let binary = &BINARY_PATH;
    let binary_as_util = binary.file_stem().unwrap().to_str().unwrap();

    // binary name equals util name?
    if let Some(&uumain) = utils.get(binary_as_util) {
        std::process::exit(uumain(args));
    }

    // binary name equals prefixed util name?
    // * prefix/stem may be any string ending in a non-alphanumeric character
    if let Some(util) = utils.keys().find(|util| {
        binary_as_util.ends_with(*util)
            && !(&binary_as_util[..binary_as_util.len() - (*util).len()])
                .ends_with(char::is_alphanumeric)
    }) {
        // prefixed util => replace 0th (aka, executable name) argument
        args[0] = (*util).to_owned();
    } else {
        // unmatched binary name => regard as multi-binary container and advance argument list
        args.remove(0);
    }

    // 0th argument equals util name?
    if !args.is_empty() {
        let util = &args[0][..];

        match utils.get(util) {
            Some(&uumain) => {
                std::process::exit(uumain(args.clone()));
            }
            None => {
                if &args[0][..] == "--help" || &args[0][..] == "-h" {
                    // see if they want help on a specific util
                    if args.len() >= 2 {
                        let util = &args[1][..];
                        match utils.get(util) {
                            Some(&uumain) => {
                                let code = uumain(vec![util.to_owned(), "--help".to_owned()]);
                                std::io::stdout().flush().expect("could not flush stdout");
                                std::process::exit(code);
                            }
                            None => {
                                println!("{}: function/utility not found", util);
                                std::process::exit(1);
                            }
                        }
                    }
                    usage(&utils);
                    std::process::exit(0);
                } else {
                    println!("{}: function/utility not found", util);
                    std::process::exit(1);
                }
            }
        }
    } else {
        // no arguments provided
        usage(&utils);
        std::process::exit(0);
    }
}