upgrade to edition 2021, clippy fixes, error fixed

Cargo.lock

@@ -60,7 +60,7 @@ dependencies = [
 
 [[package]]
 name = "lamp"
-version = "0.1.0"
+version = "0.2.0"
 dependencies = [
  "clap",
  "exitcode",
@@ -68,9 +68,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.103"
+version = "0.2.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd8f7255a17a627354f321ef0055d63b898c6fb27eff628af4d1b66b7331edf6"
+checksum = "869d572136620d55835903746bcb5cdc54cb2851fd0aeec53220b4bb65ef3013"
 
 [[package]]
 name = "strsim"

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "lamp"
-version = "0.1.0"
-authors = ["crapStone <wewr.mc@gmail.com>"]
-edition = "2018"
+version = "0.2.0"
+authors = ["crapStone <crapstone01@gmail.com>"]
+edition = "2021"
 
 build = "build.rs"
 

src/cli.rs

@@ -5,6 +5,7 @@ pub fn build_cli() -> App<'static, 'static> {
         .version(env!("CARGO_PKG_VERSION"))
         .author("crapStone <crapstone01@gmail.com>")
         .about("Utility to interact with backlight")
+        .global_setting(clap::AppSettings::ArgRequiredElseHelp)
         .arg(
             Arg::with_name("set")
                 .short("s")
@@ -47,7 +48,10 @@ pub fn build_cli() -> App<'static, 'static> {
                 .long("full")
                 .help("Sets brightness to highest value"),
         )
-        .group(ArgGroup::with_name("brightness_control").args(&["set", "inc", "dec", "get", "zer", "ful"]))
+        .group(
+            ArgGroup::with_name("brightness_control")
+                .args(&["set", "inc", "dec", "get", "zer", "ful"]),
+        )
         .arg(
             Arg::with_name("list")
                 .short("l")

src/controllers.rs

@@ -4,8 +4,6 @@ use std::io::prelude::*;
 use std::path::{Path, PathBuf};
 use std::process::exit;
 
-use exitcode;
-
 const SYS_PATHS: [&str; 2] = ["/sys/class/backlight", "/sys/class/leds"];
 
 pub trait Controller {
@@ -34,7 +32,7 @@ pub struct RawController {
 
 impl RawController {
     pub fn new(path: Box<PathBuf>) -> Self {
-        Self { path: path }
+        Self { path }
     }
 }
 
@@ -185,7 +183,7 @@ pub fn get_controllers() -> (String, HashMap<String, Box<PathBuf>>) {
 
     let mut default = None;
 
-    for path in SYS_PATHS.iter() {
+    for path in SYS_PATHS {
         if Path::new(path).exists() {
             for name in Path::new(path).read_dir().unwrap() {
                 let name = name.unwrap().path();

src/main.rs

@@ -3,12 +3,13 @@ mod controllers;
 
 use std::process::exit;
 
-use exitcode;
-
 use controllers::{Controller, LinController, LogController, RawController};
 
+use crate::cli::build_cli;
+
 fn main() {
-    let matches = cli::parse_args();
+    let app = build_cli();
+    let matches = app.get_matches();
 
     let (default_ctrl, ctrls) = controllers::get_controllers();
 
@@ -41,7 +42,7 @@ fn main() {
     } else if matches.is_present("ful") {
         controller.set_brightness(controller.get_max_brightness());
     } else {
-        panic!("{}", ERROR_MSG);
+        build_cli().print_long_help().unwrap();
     }
 
     exit(exitcode::OK);