main.rs

extern crate walkdir;

use std::error::Error;
use std::fs::File;
use std::io::{self, Read, Write};
use std::process;

use walkdir::WalkDir;

fn main() {
    if let Err(err) = try_main() {
        eprintln!("{}", err);
        process::exit(1);
    }
}

fn try_main() -> Result<(), Box<Error>> {
    let nul = 0;
    let stdout = io::stdout();
    let mut stdout = stdout.lock();

    for entry in WalkDir::new("./").into_iter().filter_map(|e| e.ok()) {
        if !entry.file_type().is_file() {
            continue;
        }

        let mut bytes_count = 0;
        let mut file = File::open(entry.path())
            .map_err(|err| format!("{}: {}", entry.path().display(), err))?;

        let mut s = Vec::with_capacity(file.metadata()?.len() as usize);
        file.read_to_end(&mut s)?;

        for b in s.into_iter() {
            if b == nul {
                writeln!(
                    stdout,
                    "{} bytes={} binary file",
                    entry.path().display(),
                    bytes_count
                )?;
                break;
            }
            bytes_count += 1;
        }
        writeln!(stdout, "{} bytes={}", entry.path().display(), bytes_count)?;
    }
    Ok(())
}