decomp-toolkit/src/cmd/shasum.rs

108 lines
3.3 KiB
Rust

use std::{
fs::{File, OpenOptions},
io::{BufRead, BufReader, Read},
path::Path,
};
use anyhow::{Context, Error, Result};
use argh::FromArgs;
use filetime::{set_file_mtime, FileTime};
use sha1::{Digest, Sha1};
#[derive(FromArgs, PartialEq, Eq, Debug)]
/// Print or check SHA1 (160-bit) checksums.
#[argh(subcommand, name = "shasum")]
pub struct Args {
#[argh(switch, short = 'c')]
/// check SHA sums against given list
check: bool,
#[argh(positional)]
/// path to file
file: String,
#[argh(option, short = 'o')]
/// touch output file on successful check
output: Option<String>,
}
const DEFAULT_BUF_SIZE: usize = 8192;
pub fn run(args: Args) -> Result<()> {
let file =
File::open(&args.file).with_context(|| format!("Failed to open file '{}'", args.file))?;
if args.check {
check(args, file)
} else {
hash(args, file)
}
}
fn check(args: Args, file: File) -> Result<()> {
let reader = BufReader::new(file);
let mut mismatches = 0usize;
for line in reader.lines() {
let line = match line {
Ok(line) => line,
Err(e) => return Err(Error::msg(format!("File read failed: {}", e))),
};
let (hash, file_name) =
line.split_once(' ').ok_or_else(|| Error::msg(format!("Invalid line: {}", line)))?;
let file_name = match file_name.chars().next() {
Some(' ') | Some('*') => &file_name[1..],
_ => return Err(Error::msg(format!("Invalid line: {}", line))),
};
let mut hash_bytes = [0u8; 20];
hex::decode_to_slice(hash, &mut hash_bytes)
.with_context(|| format!("Invalid line: {}", line))?;
let file = File::open(file_name)
.with_context(|| format!("Failed to open file '{}'", file_name))?;
let found_hash = file_sha1(file)?;
if hash_bytes == found_hash.as_ref() {
println!("{}: OK", file_name);
} else {
println!("{}: FAILED", file_name);
mismatches += 1;
}
}
if mismatches != 0 {
eprintln!("WARNING: {} computed checksum did NOT match", mismatches);
std::process::exit(1);
}
if let Some(out_path) = args.output {
touch(&out_path).with_context(|| format!("Failed to touch output file '{}'", out_path))?;
}
Ok(())
}
fn hash(args: Args, file: File) -> Result<()> {
let hash = file_sha1(file)?;
let mut hash_buf = [0u8; 40];
let hash_str = base16ct::lower::encode_str(&hash, &mut hash_buf)
.map_err(|e| Error::msg(format!("Failed to encode hash: {}", e)))?;
println!("{} {}", hash_str, args.file);
Ok(())
}
fn file_sha1(mut file: File) -> Result<sha1::digest::Output<Sha1>> {
let mut buf = [0u8; DEFAULT_BUF_SIZE];
let mut hasher = Sha1::new();
Ok(loop {
let read = file.read(&mut buf).context("File read failed")?;
if read == 0 {
break hasher.finalize();
}
hasher.update(&buf[0..read]);
})
}
fn touch<P: AsRef<Path>>(path: P) -> std::io::Result<()> {
if path.as_ref().exists() {
set_file_mtime(path, FileTime::now())
} else {
match OpenOptions::new().create(true).write(true).open(path) {
Ok(_) => Ok(()),
Err(e) => Err(e),
}
}
}