usdpl-rs/usdpl-back/src/api_common/files.rs

46 lines
1.3 KiB
Rust

//! Common low-level file operations
use std::fmt::Display;
use std::path::Path;
use std::fs::File;
use std::io::{Read, Write, self};
use std::str::FromStr;
/// Write something to a file.
/// Useful for kernel configuration files.
#[inline]
pub fn write_single<P: AsRef<Path>, D: Display>(path: P, display: D) -> Result<(), io::Error> {
let mut file = File::create(path)?;
write!(file, "{}", display)
}
/// read_single error
#[derive(Debug)]
pub enum ReadError<E> {
/// IO Error
Io(io::Error),
/// String parsing error
Parse(E),
}
impl<E: std::error::Error> std::fmt::Display for ReadError<E> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
Self::Io(io) => write!(f, "io: {}", io),
Self::Parse(e) => write!(f, "parse: {}", e),
}
}
}
impl<E: std::error::Error> std::error::Error for ReadError<E> {
}
/// Read something from a file.
/// Useful for kernel configuration files.
#[inline]
pub fn read_single<P: AsRef<Path>, D: FromStr<Err=E>, E>(path: P) -> Result<D, ReadError<E>> {
let mut file = File::open(path).map_err(ReadError::Io)?;
let mut string = String::new();
file.read_to_string(&mut string).map_err(ReadError::Io)?;
string.trim().parse().map_err(ReadError::Parse)
}