Power logger written in Rust

powerlogger.rs

use std::{
    env::args,
    fs::{read_to_string, File},
    io::Write,
    thread::sleep,
    time::Duration,
};

fn main() -> std::io::Result<()> {
    let args: Vec<String> = args().collect();
    let mut outfile = File::create(args[1].clone())?;
    outfile.write_all(b"voltage,current\n")?;
    loop {
        let voltage = read_to_string("/sys/class/power_supply/BAT0/voltage_now")
            .unwrap_or_default()
            .trim()
            .parse::<i32>()
            .unwrap_or(-1);
        let current = read_to_string("/sys/class/power_supply/BAT0/current_now")
            .unwrap_or_default()
            .trim()
            .parse::<i32>()
            .unwrap_or(-1);
        outfile.write_fmt(format_args!("{},{}\n", voltage, current))?;
        sleep(Duration::from_secs(1));
    }
}