utf8_to_gb18030.rs

use std::io::prelude::*;
use std::{fs::File, path::PathBuf};

use encoding_rs::GB18030;

fn main() -> std::io::Result<()> {
    let mut input_path = std::env::args().skip(1).next().map(PathBuf::from).unwrap();
    let mut in_file = File::open(&input_path)?;

    let mut src = String::new();
    in_file.read_to_string(&mut src)?;

    let (dst, _, _) = GB18030.encode(&src);

    input_path.set_file_name(format!(
        "gb_{}",
        input_path
            .file_name()
            .and_then(|s| s.to_str())
            .unwrap_or("")
    ));
    let mut out_file = File::create(&input_path)?;
    out_file.write_all(&dst)?;
    Ok(())
}