coreutils/src/sum/sum.rs

145 lines
3.4 KiB
Rust

#![crate_name = "sum"]
/*
* This file is part of the uutils coreutils package.
*
* (c) T. Jameson Little <t.jameson.little@gmail.com>
*
* For the full copyright and license information, please view the LICENSE file
* that was distributed with this source code.
*/
extern crate getopts;
extern crate libc;
use std::fs::File;
use std::io::{Read, Result, stdin, Write};
use std::path::Path;
#[path="../common/util.rs"]
#[macro_use]
mod util;
static NAME: &'static str = "sum";
static VERSION: &'static str = "1.0.0";
fn bsd_sum(mut reader: Box<Read>) -> (usize, u16) {
let mut buf = [0; 1024];
let mut blocks_read = 0;
let mut checksum: u16 = 0;
loop {
match reader.read(&mut buf) {
Ok(n) if n != 0 => {
blocks_read += 1;
for &byte in buf[..n].iter() {
checksum = (checksum >> 1) + ((checksum & 1) << 15);
checksum += byte as u16;
}
},
_ => break,
}
}
(blocks_read, checksum)
}
fn sysv_sum(mut reader: Box<Read>) -> (usize, u16) {
let mut buf = [0; 512];
let mut blocks_read = 0;
let mut ret = 0;
loop {
match reader.read(&mut buf) {
Ok(n) if n != 0 => {
blocks_read += 1;
for &byte in buf[..n].iter() {
ret += byte as u32;
}
},
_ => break,
}
}
ret = (ret & 0xffff) + (ret >> 16);
ret = (ret & 0xffff) + (ret >> 16);
(blocks_read, ret as u16)
}
fn open(name: &str) -> Result<Box<Read>> {
match name {
"-" => Ok(Box::new(stdin()) as Box<Read>),
_ => {
let f = try!(File::open(&Path::new(name)));
Ok(Box::new(f) as Box<Read>)
}
}
}
pub fn uumain(args: Vec<String>) -> i32 {
let mut opts = getopts::Options::new();
opts.optflag("r", "", "use the BSD compatible algorithm (default)");
opts.optflag("s", "sysv", "use System V compatible algorithm");
opts.optflag("h", "help", "show this help message");
opts.optflag("v", "version", "print the version and exit");
let matches = match opts.parse(&args[1..]) {
Ok(m) => m,
Err(f) => crash!(1, "Invalid options\n{}", f)
};
if matches.opt_present("help") {
let msg = format!("{0} {1}
Usage:
{0} [OPTION]... [FILE]...
Checksum and count the blocks in a file.", NAME, VERSION);
println!("{}\nWith no FILE, or when FILE is -, read standard input.", opts.usage(&msg));
return 0;
}
if matches.opt_present("version") {
println!("{} {}", NAME, VERSION);
return 0;
}
let sysv = matches.opt_present("sysv");
let files = if matches.free.is_empty() {
vec!["-".to_string()]
} else {
matches.free
};
let print_names = if sysv {
files.len() > 1 || files[0] != "-"
} else {
files.len() > 1
};
for file in files.iter() {
let reader = match open(file) {
Ok(f) => f,
_ => crash!(1, "unable to open file")
};
let (blocks, sum) = if sysv {
sysv_sum(reader)
} else {
bsd_sum(reader)
};
if print_names {
println!("{} {} {}", sum, blocks, file);
} else {
println!("{} {}", sum, blocks);
}
}
0
}
#[allow(dead_code)]
fn main() {
std::process::exit(uumain(std::env::args().collect()));
}