Add clap as a CLI argument parser and add debug flag to change log level

Cargo.toml

@@ -22,6 +22,7 @@ ddc = "0.2"
 ddc-hi = "0.4"
 rusb = "^0.9"
 shell-words = "1.0"
+clap = { version = "4.5.21", features = ["derive"] }
 
 [build-dependencies]
 vergen-git2 = { version = "1.0.0", features = ["build", "cargo"] }

src/app.rs

@@ -6,10 +6,10 @@
 use anyhow::{Context, Result};
 
 use crate::configuration::{Configuration, SwitchDirection};
-use crate::display_control;
 use crate::logging;
 use crate::platform::{wake_displays, PnPDetect};
 use crate::usb;
+use crate::{display_control, Args};
 
 pub struct App {
     config: Configuration,
@@ -38,8 +38,8 @@ impl usb::UsbCallback for App {
 }
 
 impl App {
-    pub fn new() -> Result<Self> {
-        logging::init_logging().context("failed to initialize logging")?;
+    pub fn new(args: Args) -> Result<Self> {
+        logging::init_logging(args.debug).context("failed to initialize logging")?;
         info!(
             "display-switch v{version} built on {timestamp} from git {git}",
             version = env!("CARGO_PKG_VERSION"),

src/logging.rs

@@ -10,16 +10,17 @@ use simplelog::*;
 
 use crate::configuration::Configuration;
 
-pub fn init_logging() -> Result<()> {
+pub fn init_logging(log_debug: bool) -> Result<()> {
+    let log_level = if log_debug {
+        LevelFilter::Debug
+    } else {
+        LevelFilter::Info
+    };
+
     Ok(CombinedLogger::init(vec![
-        TermLogger::new(
-            LevelFilter::Debug,
-            Config::default(),
-            TerminalMode::Mixed,
-            ColorChoice::Auto,
-        ),
+        TermLogger::new(log_level, Config::default(), TerminalMode::Mixed, ColorChoice::Auto),
         WriteLogger::new(
-            LevelFilter::Debug,
+            log_level,
             Config::default(),
             File::create(Configuration::log_file_name()?)?,
         ),

src/main.rs

@@ -8,7 +8,7 @@
 extern crate log;
 
 use anyhow::Result;
-use std::env;
+use clap::Parser;
 
 #[cfg(target_os = "windows")]
 use winapi::um::wincon::{AttachConsole, ATTACH_PARENT_PROCESS};
@@ -21,6 +21,14 @@ mod logging;
 mod platform;
 mod usb;
 
+#[derive(Parser, Debug)]
+#[command(version)]
+struct Args {
+    /// Print debug information
+    #[arg(short, long, default_value_t = false)]
+    debug: bool,
+}
+
 /// On Windows, re-attach the console, if parent process has the console. This allows
 /// to see the log output when run from the command line.
 fn attach_console() {
@@ -32,14 +40,9 @@ fn attach_console() {
 
 fn main() -> Result<()> {
     attach_console();
+    let args = Args::parse();
 
-    let args: Vec<String> = env::args().collect();
-    if args.len() == 2 && args[1] == "--version" {
-        println!("{} v{}", env!("CARGO_PKG_NAME"), env!("CARGO_PKG_VERSION"));
-        return Ok(());
-    }
-
-    let app = app::App::new()?;
+    let app = app::App::new(args)?;
     app.run()?;
     Ok(())
 }