ssed.rs

use std::io::File;

fn main() {
    let args = ::std::os::args();
    let string = &args[1];
    let replace = &args[2];
    let path = &args[3];
    assert!(replace.len() == string.len());
    println!("Replacing`{}` with `{}` in `{}`...", string, replace, path);
    let chars: Vec<char> = string.as_slice().chars().collect();
    let rchars: Vec<char> = replace.as_slice().chars().collect();
    let mut bytes = File::open(&Path::new(path)).read_to_end().unwrap();
    'each_byte: for i in range(0, bytes.len() - chars.len()) {
        for j in range(0, chars.len() - 1) {
            let chdiff = chars[j] as i32 - chars[j + 1] as i32;
            let bdiff = bytes[i + j] as i32 - bytes[i + j + 1] as i32;
            if chdiff != bdiff {
                continue 'each_byte;
            }
        }
        for j in range(0, chars.len()) {
            let diff = chars[j] as i32 - rchars[j] as i32;
            bytes[i + j] = (bytes[i + j] as i32 - diff) as u8;
        }
    }
    let mut file = File::create(&Path::new(*path + ".modif"));
    file.write(bytes.as_slice()).unwrap();
}