linapi 0.5.3

//! Utility functions
use crate::system::UEventAction;
use std::{collections::HashMap, fs, io::prelude::*, path::Path};

/// Technically Linux requires sysfs to be at `/sys`, calling it a system
/// configuration error otherwise.
///
/// But our upcoming distro is planning to experiment with filesystem layout
/// changes, including of `/sys`, so do this to allow easily changing it.
pub const SYSFS_PATH: &str = "/sys";

/// Kernel Module location. Same reasons as [`SYSFS_PATH`].
pub const MODULE_PATH: &str = "/lib/modules";

/// Device file location. Same reasons as [`SYSFS_PATH`].
pub const DEV_PATH: &str = "/dev";

/// Read a uevent file
///
/// # Arguments
///
/// - `path`, path to the uevent file.
pub fn read_uevent(path: &Path) -> HashMap<String, String> {
    let mut map = HashMap::new();
    for line in fs::read_to_string(path).unwrap().split_terminator('\n') {
        let line: &str = line;
        let mut i = line.split('=');
        let key = i.next().unwrap().into();
        let val = i.next().unwrap().into();
        map.insert(key, val);
    }
    map
}

/// Write a uevent file
///
/// # Arguments
///
/// - `path`, path to the uevent file.
pub fn write_uevent(
    path: &Path,
    action: UEventAction,
    uuid: Option<String>,
    args: HashMap<String, String>,
) {
    let mut data = String::new();
    match action {
        UEventAction::Add => data.push_str("add"),
        UEventAction::Change => data.push_str("change"),
        UEventAction::Remove => data.push_str("remove"),
    }
    data.push(' ');
    if let Some(uuid) = uuid {
        data.push_str(&uuid);
        data.push(' ');
    }
    for (k, v) in args {
        data.push_str(&k);
        data.push('=');
        data.push_str(&v);
        data.push(' ');
    }
    //
    let mut f = fs::OpenOptions::new().write(true).open(path).unwrap();
    f.write_all(data.trim().as_bytes()).unwrap();
}