fn main() {
	if std::env::args().len() != 2 {
		eprintln!("usage: popline <file>\n");
		eprintln!("removes the first line of a file and rewrites it to disk without that line");
		std::process::exit(1);
	}

	let file = std::path::PathBuf::from(std::env::args().nth(1).unwrap());
	let string = std::fs::read_to_string(&file).unwrap();
	let mut lines = string.lines();

	let line = match lines.next() {
		None => {
			std::process::exit(1);
		}
		Some(line) => line,
	};

	let write = lines.collect::<Vec<&str>>().join("\n");
	std::fs::write(file, write).unwrap();

	println!("{line}");
}