1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
// Filebuffer -- Fast and simple file reading
// Copyright 2016 Ruud van Asseldonk
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// A copy of the License has been included in the root of the repository.
// This example implements the `sha256sum` program in Rust using the IO primitives in the
// standard library. Compare with `sha256sum_filebuffer` which uses the Filebuffer library.
use std::env;
use std::fs;
use std::io;
use std::io::BufRead;
use sha2::{Sha256, Digest};
fn main() {
for fname in env::args().skip(1) {
let file = fs::File::open(&fname).expect("failed to open file");
let mut reader = io::BufReader::new(file);
let mut hasher = Sha256::new();
loop {
let consumed_len = {
let buffer = reader.fill_buf().expect("failed to read from file");
if buffer.len() == 0 {
// End of file.
break;
}
hasher.update(buffer);
buffer.len()
};
reader.consume(consumed_len);
}
let result = hasher.finalize();
let result = hex::encode(result.as_slice());
// Match the output format of `sha256sum`, which has two spaces between the hash and name.
println!("{} {}", result, fname);
}
}
|
