use std::{fs, io, io::prelude::*, path::PathBuf};
fn mess_in_the_middle(path: PathBuf) -> io::Result<()> {
let mut file = fs::OpenOptions::new().read(false).write(true).open(path)?;
file.seek(io::SeekFrom::Start(file.metadata()?.len() / 2))?;
file.write_all(b"hello")?;
Ok(())
}
fn main() -> Result<(), Box<dyn std::error::Error>> {
let mut args = std::env::args().skip(1);
let scmd = args.next().expect("sub command");
match &*scmd {
"mess-in-the-middle" => mess_in_the_middle(PathBuf::from(args.next().expect("path to file to mess with")))?,
_ => unimplemented!("Unknown subcommand: {}", scmd),
};
Ok(())
}